Limiting nature of continuum generation in silicon
Prakash Koonath, Daniel R. Solli, and Bahram Jalali
Spectral broadening in silicon through self-phase modulation is studied numerically and experimentally in the normal dispersion regime. Temporal dynamics of the free carriers generated during the propagation of optical pulses, through the process of two-photon absorption, affect the amplitude and ph ... [Appl. Phys. Lett. 93, 091114 (2008)] published Thu Sep 4, 2008.
Variable optical delays at 1.55 mu m using fast light in an InAs/InP quantum dash based semiconductor optical amplifier
A. Martinez, G. Aubin, F. Lelarge, R. Brenot, J. Landreau et al.
Room temperature optical variable delays are demonstrated using InAs/InP quantum dash semiconductor optical amplifiers (SOAs) at 1.55 [mu]m. A microwave frequency modulated single optical beam allows to demonstrate fast light through the achievement of maximum optical delays of 136 ps at 250 MHz an ... [Appl. Phys. Lett. 93, 091116 (2008)] published Thu Sep 4, 2008.
Single-laser-shot detection of nitric oxide in reacting flows using electronic resonance enhanced coherent anti-Stokes Raman scattering
Ning Chai, Sameer V. Naik, Normand M. Laurendeau, Robert P. Lucht, Sukesh Roy et al.
Single-laser-shot electronic resonance enhanced coherent anti-Stokes Raman scattering (ERE-CARS) spectra of nitric oxide (NO) were generated using the 532 nm output of an injection-seeded Nd:YAG (yttrium aluminum garnet) laser as the pump beam, a broadband dye laser at approximately 591 nm as the St ... [Appl. Phys. Lett. 93, 091115 (2008)] published Thu Sep 4, 2008.
Anisotropic optical gain in m-plane In[sub x]Ga[sub 1 - x]N/GaN multiple quantum well laser diode wafers fabricated on the low defect density freestanding GaN substrates
T. Onuma, K. Okamoto, H. Ohta, and S. F. Chichibu
The threshold power density for the stimulated emission (SE) at 400 nm of m-plane InGaN/GaN multiple quantum well (QW) laser diode (LD) wafer excited with a stripe along the c-axis was found to be lower than along the a-axis, although the SEs exhibited transverse electric field mode for both configu ... [Appl. Phys. Lett. 93, 091112 (2008)] published Thu Sep 4, 2008.
Solitons and vortices in honeycomb defocusing photonic lattices
K. J. H. Law, H. Susanto, and P. G. Kevrekidis
Solitons and necklaces in the first band gap of a two-dimensional optically induced honeycomb defocusing photonic lattice are theoretically considered. It is shown that dipoles, soliton necklaces, and vortex necklaces exist and may possess regions of stable propagation through a photorefractive crys ... [Phys. Rev. A 78, 033802 (2008)] published Thu Sep 4, 2008.
Band edge states of the = 0 gap of Fibonacci photonic lattices
A. Bruno-Alfonso, E. Reyes-Gomez, S. B. Cavalcanti, and L. E. Oliveira
The stationary and normally incident electromagnetic modes in Fibonacci lattices with generating layers of positive and negative indices of refraction are calculated by a transfer-matrix technique. It is shown that the condition for constructive interference of reflected waves is fulfilled when the ... [Phys. Rev. A 78, 035801 (2008)] published Thu Sep 4, 2008.
Improved beam uniformity in multimode fibers using piezoelectric-based spatial mode scrambling for medical applications
Lianshan Yan, X. Steve Yao, Lynn Lin, and Xiaojun Chen
We improve the beam uniformity passing through multimode fibers using piezoelectric-based spatial mode scrambling. Both fiber squeezing and stretching techniques are applied and compared. A more than sixfold difference in the power intensity crossing the output beam profile without mode scrambling c ... [Opt. Eng. 47, 090502 (2008)] published Thu Sep 4, 2008.
Multiphoton absorption in CsLiB[sub 6]O[sub 10] with femtosecond infrared laser pulses
J. N. Babu Reddy, V. B. Naik, Suja Elizabeth, H. L. Bhat, N. Venkatram et al.
Nonlinear absorption and refraction characteristics of cesium lithium borate (CsLiBO) crystal have been studied using Z-scan technique. Ti:sapphire laser with 110 fs pulse width operating at 800 nm wavelength and pulse repetition rate of 1 kHz is used as the source of photons. Intensity of the laser ... [J. Appl. Phys. 104, 053108 (2008)] published Thu Sep 4, 2008.
Truncated photonic crystal cavities with optimized mode confinement
Carl A. Bauer, Gregory R. Werner, and John R. Cary
Optimization of a truncated, dielectric photonic crystal cavity leads to configurations that are far from truncated crystal cavities, and which have significantly better radiation confinement. Starting from a two-dimensional truncated photonic crystal cavity with optimal Q-factor, moving the rods fr ... [J. Appl. Phys. 104, 053107 (2008)] published Thu Sep 4, 2008.
Fabrication of quartz mold with submicrometer features based on laser-assisted contact transfer method
Yung-Chun Lee, Chun-Hsiang Chen, Cheng-Yu Chiu, and Fuh-Yu Chang
We report a simple method for fabricating quartz molds with submicrometer- and nanoscaled surface structures. It utilizes an excimer laser as the energy source and a roller-type contact-printing setup for directly transferring a patterned metallic thin film from a silicon mold to a quartz substrate. ... [J. Micro/Nanolith. MEMS MOEMS 7, 033006 (2008)] published Thu Sep 4, 2008.
Compact high power broadband Er[sup 3+] - Yb[sup 3+]-codoped superfluorescent fiber source
Feng Song, Zhenzhou Cheng, Changguang Zou, Lin Han, Xiaochen Yu et al.
Compact high power broadband superfluorescent fiber source has been demonstrated using an ultrashort ErYb-codoped phosphate glass fiber. The fiber is 10.4-cm-long and at 1.68 W pump power, an output power of 16.85 mW, a mean wavelength of 1540.9 nm, a bandwidth of 18.4 nm, and a slope efficiency of ... [Appl. Phys. Lett. 93, 091108 (2008)] published Wed Sep 3, 2008.
High-power AlInGaN-based violet laser diodes with InGaN optical confinement layers
Sung-Nam Lee, J. K. Son, H. S. Paek, Y. J. Sung, K. S. Kim et al.
InGaN optical confinement layers (OCLs) were introduced into blue-violet AlInGaN-based laser diodes (LDs), resulting in the drastic improvements of lasing performance. Comparing with conventional LD structure, the lowest threshold current density of 2.3 kA/cm has been achieved by adding 100-nm-thic ... [Appl. Phys. Lett. 93, 091109 (2008)] published Wed Sep 3, 2008.
Three-dimensional model for light-induced chaotic rotations in liquid crystals under spin and orbital angular momentum transfer processes
Etienne Brasselet, Bruno Piccirillo, and Enrico Santamato
Liquid crystals interacting with light represent a unique class of soft-matter systems that exhibit various generic nonlinear behaviors, including chaotic rotational dynamics. Despite several experimental observations, complex nematic liquid crystal director rotations in presence of spin and orbital ... [Phys. Rev. E 78, 031703 (2008)] published Wed Sep 3, 2008.
Cooling an optical fiber to 4.5 K by indirect thermal contact with a liquid-helium flow and spectroscopic temperature measurements
Daisuke Hashimoto and Kaoru Shimizu
We have made it possible to cool a 10-m-long optical fiber to 4.5 K in a compact helium-flow cryostat. The cryostat is vacuum loaded and the cooling principle is based on thermal contact with a copper holder cooled by the liquid-helium flow. To measure the temperature directly, we employed two diffe ... [Rev. Sci. Instrum. 79, 093102 (2008)] published Wed Sep 3, 2008.
Two-photon beating experiment using biphotons generated from a two-level system
Jianming Wen, Shengwang Du, Morton H. Rubin, and Eun Oh
We propose a two-photon beating experiment based upon biphotons generated from a resonant pumping two-level system operating in a backward geometry. On the one hand, the linear optical-response leads biphotons produced from two sidebands in the Mollow triplet to propagate with tunable refractive ind ... [Phys. Rev. A 78, 033801 (2008)] published Wed Sep 3, 2008.
Spectral characteristics of continuous wave broadband from a fiber laser with a low dispersion fiber in the cavity
Deepa Venkitesh and R. Vijaya
The spectral width of the continuous wave broadband generated in an erbium doped fiber ring laser containing a dispersion shifted fiber (DSF) in a filterless cavity is found to be governed by the nature of the gain spectrum of the doped fiber, in addition to the nonlinear effects. This dependence is ... [J. Appl. Phys. 104, 053104 (2008)] published Wed Sep 3, 2008.
New signal-processing instrument for dual-wavelength/split-beam spectrophotometers
Charles W. Wade
Several new techniques for processing signals from dual-wavelength/split-beam spectrophotometers are discussed and contrasted with earlier methods. Based on these techniques, a signal-processing instrument has been built which achieves significant improvements in speed, range, accuracy, and noise re ... [Rev. Sci. Instrum. 46, 987 (2008)] published Wed Sep 3, 2008.
Demountable optical windows using heat shrinkable tubing
R. N. Zitter and D. F. Koster
Heat shrinkable tubing provides a new way of mounting optical windows on systems that is simple and quick and permits fast and easy removal. ... [Rev. Sci. Instrum. 46, 1116 (2008)] published Wed Sep 3, 2008.
Current-regulated, high-voltage power supply for cw gas lasers
Dwight Maxson, D. G. Seiler, and Larry Tipton
An economical, high-voltage, highly stable, current-regulated power supply with less than 0.1% rms ripple is described. The dynamic capabilities of 030 kV and 030 mA provide a versatile instrument for use with many cw gas lasers. ... [Rev. Sci. Instrum. 46, 1110 (2008)] published Wed Sep 3, 2008.
Water-jacketed electric field birefringence cell
E. D. Baily
A simple water-jacketed electric birefringence cell is described which is suitable for use with a laser light source. The electrodes in the cell form an integral part of the cell walls, thus permitting a low internal volume (~ 0.4 ml) to be achieved. This makes the cell particularly suitable for use ... [Rev. Sci. Instrum. 46, 1105 (2008)] published Wed Sep 3, 2008.
Simple and reliable subsonic HF chemical laser with 40 W power output (16 W DF)
D. Proch, H. Pummer, K. L. Kompa, and J. Wanner
The design and performance of a transverse flow subsonic chemical laser with a total power output of 40 W for HF and 16 W for DF are presented. Laser operation has been observed in the wavelength range 2.63.0 [mu] for HF and 3.64.0 [mu] for DF resulting from v=21 and 10 transitions of the HF molecul ... [Rev. Sci. Instrum. 46, 1101 (2008)] published Wed Sep 3, 2008.
Microwave discharge atom source for chemical lasers
R. A. McFarlane
A high-power, cw microwave magnetron is used to produce a discharge in a gas column flowing at high velocity. The large atom production rate obtained makes this a valuable atom source for chemical laser application. ... [Rev. Sci. Instrum. 46, 1063 (2008)] published Wed Sep 3, 2008.
Prealignment of gas laser cavities
K. G. Hernqvist and A. H. Firester
A method of coarse alignment and fine tuning of the cavity of a gas laser is presented. The laser cavity to be aligned is treated as a FabryPerot cavity, and its transmission of a frequency-swept laser is maximized. An experiment is described showing that this fine-tuning procedure results in maximu ... [Rev. Sci. Instrum. 46, 1040 (2008)] published Wed Sep 3, 2008.
High-vacuum Raman cell for the study of finite particle effects
H. K. Bockelmann, R. G. Schlecht, and R. McKay
A high-vacuum Raman cell using the backscattering geometry for use in studies of microcrystals, surface effects, and physical and chemical adsorption is described. The circuit and description for a temperature controller are also included. ... [Rev. Sci. Instrum. 46, 1008 (2008)] published Wed Sep 3, 2008.
Ultraviolet source suitable for Tokamak preionization
P. Smeulders
In order to ionize molecular deuterium a photon energy greater than 15.6 eV is required. This is created by radiation from bombardment of a thick wall by energetic electrons, as in x- tubes. A high voltage pulse extracts the electrons by field emission from the sharp pointed electrode and accelerate ... [Rev. Sci. Instrum. 46, 909 (2008)] published Wed Sep 3, 2008.
Plastic optical fiber displacement sensor for study of the dynamic response of a solid exposed to an intense pulsed electron beam
R. Bailly-Salins
The principle of the branched fiber bundle sensor has been known for many years. The apparatus which is described in this paper is distinguished by simple fabrication, low cost, high sensitivity, and a fast response time. It is used for measuring the velocity of the back surface of an irradiated alu ... [Rev. Sci. Instrum. 46, 879 (2008)] published Wed Sep 3, 2008.
CO[sub 2] oscillator--pulse shaper--amplifier system producing 0.1 J in a 500 psec laser pulse
Hoi-Sing Kwok and Eli Yablonovitch
The output of an optical free induction decay pulse generator was amplified up to the 0.1 J level. A pulse width of 500 psec was resolved on a Tektronix 519 oscilloscope using a pyroelectric detector. This agreed well with a linear computer model of the system response. ... [Rev. Sci. Instrum. 46, 814 (2008)] published Wed Sep 3, 2008.
Number fluctuation correlation function for light scattering in crossed laser beams
G. C. Duncan and M. R. Olschewsky
The number fluctuation correlation function for light scattered by particles in crossed, equal intensity laser beams is derived. The beams are assumed to possess intensity profiles that are respectively Gaussian transverse to the directions of propagation. A further Gaussian dependence introduces th ... [J. Chem. Phys. 63, 1868 (2008)] published Wed Sep 3, 2008.
On the solution of the phase retrieval problem
B. J. Hoenders
It is shown that the intensity in the image plane of a microscope determines uniquely the phase of the corresponding image wavefunction up to an over-all phase. This result is obtained using the a priori information that both the image wavefunction and the unperturbed wavefunction in the Fraunhofer ... [J. Math. Phys. 16, 1719 (2008)] published Wed Sep 3, 2008.
A Goursat problem for the fourth moment equation
M. N. Oguztoreli
The solution of a Goursat problem for the pseudoparabolic equation satisfied by the fourth statistical moment of an initially plane wave propagating in a random medium is presented, using an integrodifferential equation technique. Two-dimensional propagations are considered. ... [J. Math. Phys. 16, 1244 (2008)] published Wed Sep 3, 2008.
A definition of quantum detection point processes
C. Benard
A definition of quantum particle detection point processes is given for normal and locally normal systems. This is realized by building coincidence measurement operators, describing in a thoroughly quantum formalism the coincidence experiments that have been actually performed (photon) or that might ... [J. Math. Phys. 16, 710 (2008)] published Wed Sep 3, 2008.
Electro-Optic Modulation of Single Photons
Pavel Kolchin, Chinmay Belthangady, Shengwang Du, G. Y. Yin, and S. E. Harris
We use the Stokes photon of a biphoton pair to set the time origin for electro-optic modulation of the wave function of the anti-Stokes photon thereby allowing arbitrary phase and amplitude modulation. We demonstrate conditional single-photon wave functions composed of several pulses, or instead, ha ... [Phys. Rev. Lett. 101, 103601 (2008)] published Wed Sep 3, 2008.
Two Regimes of Slow-Light Losses Revealed by Adiabatic Reduction of Group Velocity
R. J. P. Engelen, D. Mori, T. Baba, and L. Kuipers
The losses in a photonic crystal waveguide were measured with a near-field microscope in the group velocity range of c/7 down to c/200. Our measurements show that the losses scale proportional to v for group velocities above c/30. Below c/30, the losses are no longer described by the same power-law ... [Phys. Rev. Lett. 101, 103901 (2008)] published Wed Sep 3, 2008.
Influence of residual disorder on the anticrossing of Bloch modes probed in k space
N. Le Thomas, V. Zabelin, R. Houdre, M. V. Kotlyar, and T. F. Krauss
We retrieve the dispersion properties of photonic crystal waveguides near the band edge with high experimental accuracy. The dispersion diagram of the waveguide modes in the complex-valued plane is directly measured in the far field by using a Fourier space imaging technique. We show that the invest ... [Phys. Rev. B 78, 125301 (2008)] published Tue Sep 2, 2008.
Ultrafast probing of light-matter interaction in a midinfrared quantum cascade laser
Wolfgang Parz, Thomas Muller, Juraj Darmo, Karl Unterrainer, Max Austerer et al.
In this work, we study the interaction of ultrashort midinfrared pulses with the active medium of an InGaAs/InAlAs/InP quantum cascade laser emitting at an 11.7 [mu]m wavelength. Applying an electro-optic sampling technique allowed us to measure the complete phase resolved transmission spectra at o ... [Appl. Phys. Lett. 93, 091105 (2008)] published Tue Sep 2, 2008.
Electric control of spatial beam position based on the Goos--H[a-umlaut]nchen effect
Yi Wang, Zhuangqi Cao, Honggen Li, Jun Hao, Tianyi Yu et al.
A structure of symmetrical metal-cladding waveguide, which contains optically nonlinear material in the guiding layer, is proposed to control the lateral shift of the reflected beam via an external electric field. Owing to the high sensitivity of ultrahigh-order modes, any minute index change of the ... [Appl. Phys. Lett. 93, 091103 (2008)] published Tue Sep 2, 2008.
Mercury Bromide (HgBr[sub 2]): A promising nonlinear optical material in IR region with a high laser damage threshold
T. Liu, J. Qin, G. Zhang, T. Zhu, F. Niu et al.
Nonlinear optical (NLO) crystals have played a key role in laser technology, and the existing materials for the IR range showed relatively low laser damage threshold in common. A NLO material HgBr is presented here. It shows a powder second harmonic generation about ten times as large as that of KHP ... [Appl. Phys. Lett. 93, 091102 (2008)] published Tue Sep 2, 2008.
Influence, detection, and measurement of depolarization in Hertzian reflecto-polarimetry and reflecto-ellipsometry
R. Sardos
Radar specialists know that during the reflection of waves the phenomenon of depolarization appears in a more or less intense manner depending upon atmospheric conditions. The measurement of depolarization in a laboratory setting is difficult because the problem involves measuring a weak, incoherent ... [Rev. Sci. Instrum. 46, 1503 (2008)] published Tue Sep 2, 2008.
Laser-triggered spark gap and Kerr cell shutter using a low impedance transmission line
J.-C. Diels
Kerr cells driven by 50 Omega impedance circuits are generally risetime limited due to the capacitance of the cell. Faster risetimes may be achieved with lower impedance circuits. However, the lower the impedance, the more reflections occur at the localized elements and the higher the electric field ... [Rev. Sci. Instrum. 46, 1704 (2008)] published Tue Sep 2, 2008.
Water spark gap for a nitrogen laser
Seishiro Saikan and Fujio Shimizu
Satisfactory operation of the Blumlein type nitrogen laser was obtained by using a water-filled spark gap. The water-filled spark gap uses flowing water, and the Blumlein circuit is charged by a Marx-bank driver. ... [Rev. Sci. Instrum. 46, 1700 (2008)] published Tue Sep 2, 2008.
Versatile cells for optical studies in fluids
R. Hocken, M. R. Moldover, E. Muth, and S. Gerner
A sample cell for optical studies of fluids is described. ... [Rev. Sci. Instrum. 46, 1699 (2008)] published Tue Sep 2, 2008.
Technique for background elimination in infrared measurements
Kenneth L. Moore
A technique has been devised for electronically eliminating background signals in chopped infrared measuring systems by subtracting a reference signal of proper frequency, phase, and amplitude from the background signal. Subsequently acquired point-source or distant-small-source signals are converte ... [Rev. Sci. Instrum. 46, 1667 (2008)] published Tue Sep 2, 2008.
Apparatus for rapid measurement of optical rotation changes
Motoyuki Tsuda
An apparatus for rapid measurement of optical rotation changes has been developed in the face of large absorption changes with time resolutions of 10 [mu]sec (sensitivity 0.018 degrees ) and 4 msec (sensitivity 0.0016 degrees ). Applications are briefly described for the study of rapid transient pro ... [Rev. Sci. Instrum. 46, 1419 (2008)] published Tue Sep 2, 2008.
Crossed-beam apparatus for simultaneous spectrophotometric observation and microwave exposure of biochemical samples
John W. Allis, Claude M. Weil, and David E. Janes, Jr.
A spectrophotometer has been adapted for use as a simultaneous observationexposure system for irradiation of biochemical samples by 1.72.6 GHz electromagnetic radiation. A waveguide applicator is mounted vertically in the sample compartment of a Cary 15 spectrophotometer such that the sample can be ... [Rev. Sci. Instrum. 46, 1344 (2008)] published Tue Sep 2, 2008.
Versatile wide range precision spectrophotometer allowing simultaneous measurement of transmittance and reflectance
Alfred P. DeFonzo
An optical system is described having three equal paths split from a single beam and recombined into a single beam. A method for electronically processing the signal to obtain the transmittance and reflectance as well as an interfacing system, which allows complete programming of scans and direct da ... [Rev. Sci. Instrum. 46, 1329 (2008)] published Tue Sep 2, 2008.
Doppler-independent selective heterodyne radiometry for detection of remote species
Malvin Carl Teich
A multiple-frequency heterodyne radiometer is proposed for the detection of radiation from known species moving with unknown velocities. Expressions for the signal-to-noise ratio and the minimum detectable total power are obtained for sinusoidal signals and for Gaussian signals with both Gaussian an ... [Rev. Sci. Instrum. 46, 1313 (2008)] published Tue Sep 2, 2008.
Q-switching of laser cavity with an open-air spark gap
S. Ishii and B. Ahlborn
A laser cavity has been Q-switched using a spark plasma as the optically active element. ... [Rev. Sci. Instrum. 46, 1287 (2008)] published Tue Sep 2, 2008.
Digital light scattering photometer
S. P. Lee, W. Tscharnuter, and B. Chu
We have constructed a three-channel digital (ratio) photometer using TTL integrated circuit. Each channel has its own separate scaler and timer with eight-digit counting capacities. The instrument is particularly useful for precise determinations of correlation lengths of critical fluid systems and ... [Rev. Sci. Instrum. 46, 1278 (2008)] published Tue Sep 2, 2008.
One nanosecond CO[sub 2] laser chain for laser--target interaction studies
F. Rheault, J.-L. Lachambre, P. Lavigne, H. Pepin, and H. A. Baldis
A CO oscillatoramplifier laser system generating short pulses of radiation in the gigawatt range is described. Emphasis is laid upon self-oscillation problems associated with a high-gain amplifier chain. The insertion of SF, Freon, and CHOH cells between the amplifier modules is found efficient in s ... [Rev. Sci. Instrum. 46, 1244 (2008)] published Tue Sep 2, 2008.
Two-channel laboratory scattering meter
W. R. McCluney
An instrument was designed and built that measures the light scattered at 2 degrees and at 90 degrees simultaneously. The instrument employs a laser source, solid-state detectors, and a flow-through scattering cell for laboratory use. A Mie theory computer program was used to calculate the theoret ... [Rev. Sci. Instrum. 46, 1231 (2008)] published Tue Sep 2, 2008.
Laser temperature-jump spectrophotometer using stimulated Raman effect in H[sub 2] gas for the study of nanosecond fast chemical relaxation times
Syed Ameen
A laser temperature-jump spectrophotometer for the study of chemical relaxation times with a heating time of about 18 nsec is described. The stimulated Raman effect in hydrogen gas at 80-atm pressure produces a frequency shift of a neodymium-glass laser from 1.06 to 1.89 [mu], at which the absorbanc ... [Rev. Sci. Instrum. 46, 1209 (2008)] published Tue Sep 2, 2008.
Single photon fluorimetry
Dean W. Chandler
We present modifications of the phase fluorimeter previously described by Schlag et al. These modifications make the instrument more versatile and eliminate the need for custom-made components. ... [Rev. Sci. Instrum. 46, 786 (2008)] published Tue Sep 2, 2008.
Hot window, metal vapor tube
D. E. Altman, G. J. Barstow, M. Geller, G. Mooradian, C. Ingram et al.
A new quartz laser tube, which can operate at 1000 degrees C for metal vapors, has been built. The tube was operated in a three-zone oven, with the Brewster windows at a slightly higher temperature than the main laser body. Thus, a buffer gas was not necessary to prevent condensation of the metal on ... [Rev. Sci. Instrum. 46, 666 (2008)] published Tue Sep 2, 2008.
High performance, far-infrared bolometer working directly in a helium bath
N. Coron, G. Dambier, J. Leblanc, and J-P. Moalic
This paper describes the mounting of a high performance, far-infrared, three-part bolometer designed to permit its use directly in a helium bath. It can be matched with low loss to any optical system or to a waveguide. Optimal performance and constant characteristics have been obtained; D (at 4 K an ... [Rev. Sci. Instrum. 46, 492 (2008)] published Tue Sep 2, 2008.
Simple, adjustable lens holder
Donald A. Jennings
The construction of a simple, adjustable lens holder is described. This lens holder is unique in that it will firmly hold small lenses without taking up space at the edge of the lens or stopping them down. ... [Rev. Sci. Instrum. 46, 487 (2008)] published Tue Sep 2, 2008.
Phase fluorometer with a continuously variable frequency
M. Hauser and G. Heidt
Primarily to investigate nonexponentially decaying fluorences, a phase fluorometer has been developed with a frequency continously variable between 0.5 and 72 MHz. ... [Rev. Sci. Instrum. 46, 470 (2008)] published Tue Sep 2, 2008.
Application of multilayer dielectric coatings to cylindrical substrates
A. H. Firester, D. M. Hoffman, and M. E. Heller
Occasionally the need arises for a multilayer dielectric coating applied to a cylindrical surface. We describe a technique and device for making and simultaneously monitoring multilayer dielectric coatings on cylindrical substrates, and some typical results which demonstrate the degree of filter uni ... [Rev. Sci. Instrum. 46, 335 (2008)] published Tue Sep 2, 2008.
Laser beam waist determination by means of multiphoton ionization
E. H. A. Granneman and M. J. van der Wiel
The twophoton ionization process in Cs at lambda = 4545 A is used as a tool for accurate measurement of an Arion laser beam waist. The method is based on the variation of the relative multiphoton ionization yield with the position of a lens between laser and ionization region; it does not require kn ... [Rev. Sci. Instrum. 46, 332 (2008)] published Tue Sep 2, 2008.
Conversion of a commercial CO[sub 2] laser to CO operation at 5.6 mu
J. A. Davis
Modifications on a commercial room temperature CO laser to create a CO laser are discussed. Powers of 1 W were easily obtained in the 5.45.6 [mu] wavelength region. ... [Rev. Sci. Instrum. 46, 323 (2008)] published Tue Sep 2, 2008.
Simple single and tandem microchannelplate mountings for x - uv or low energy particle windowless image converters
L. Bettinali, F. Pecorella, and J. P. Rager
Full details are given for the realization of a windowless image converter for low energy particle or soft xray spectroscopy, based on the use of new microchannelplate mountings in which the electrical contacts are secured by small spring load pincontacts. Among other improvements, this kind of moun ... [Rev. Sci. Instrum. 46, 322 (2008)] published Tue Sep 2, 2008.
High power CO[sub 2] laser energy detector
A. A. Offenberger, P. R. Smy, and N. H. Burnett
A CO laser energy detector is described which uses the pressure rise generated in a vaccum cell by gaseous infrared absorption to provide linear energy detection over many decades, good responsivity, wide aperture, and inline beam monitoring. Nonadiabatic pressure measurements resulting when the bea ... [Rev. Sci. Instrum. 46, 317 (2008)] published Tue Sep 2, 2008.
A simple, reliable waveguide dye laser for ophthalmological applications
P. Burlamacchi, R. Pratesi, and U. Vanni
The principle of operation, construction, and performance of a compact waveguide dye laser, especially designed as a source of retinal photocoagulators, are described, The guiding effects produced by the thermal gradients induced by the pumping pulse and the use of closed resonator make the laser ve ... [Rev. Sci. Instrum. 46, 281 (2008)] published Tue Sep 2, 2008.
Thermal blooming compensation using coherent optical adaptive techniques (COAT)
William B. Bridges and James E. Pearson
Real-time compensation for thermally induced beam distortion has been demonstrated using a phase-adaptive aperture subdivided into 18 elements coupled with an 18-channel multidither servo system. The results were obtained using an argon ion laser and a nonlinear liquid cell placed in the near field ... [Appl. Phys. Lett. 26, 539 (2008)] published Tue Sep 2, 2008.
Equivalence of the coupled-mode and Floquet-Bloch formalisms in periodic optical waveguides
A. Yariv and A. Gover
A comparison of two theories used to analyze distributed feedback lasers and periodic optical devices finds them, contrary to some claims, to be formally equivalent. ... [Appl. Phys. Lett. 26, 537 (2008)] published Tue Sep 2, 2008.
Transient effects in wavelength-modulated dye lasers
C. L. Tang, J. M. Telle, and C. Ghizoni
A new laser transient effect is observed in a wavelength-modulated cw dye laser. A theory for this effect is developed and shown to be in close agreement with the observed transients. ... [Appl. Phys. Lett. 26, 534 (2008)] published Tue Sep 2, 2008.
Excitation mechanism of the He-I[sup + ] laser
T. Shay, H. Kano, and G. J. Collins
We have investigated the afterglow decay rates of sixteen iodine ion, I(II), laser lines in spontaneous emissions. All lines originate from the four triplet terms of the 5s5p(D)6p electronic configuration. The variation of the I(II) spontaneous emission decay rates with increasing iodine pressure pr ... [Appl. Phys. Lett. 26, 531 (2008)] published Tue Sep 2, 2008.
Room-temperature heterojunction laser diodes of In[sub x]Ga[sub 1 - x]As/In[sub y]Ga[sub 1 - y]P with emission wavelength between 0.9 and 1.15 mu m
C. J. Nuese and G. H. Olsen
Vapor-grown p-n heterojunction laser structures of InGaAs/InGaP have been prepared with laser threshold current densities as low as 15 000 A/cm at room temperature and 1000 A/cm at 77 degrees K. Emission wavelengths between 1.025 and 1.15 [mu]m have been obtained at 300 degrees K. ... [Appl. Phys. Lett. 26, 528 (2008)] published Tue Sep 2, 2008.
Gain spectrum of a high-pressure CO[sub 2] laser
J. L. Miller, A. H. M. Ross, and E. V. George
The gain spectrum of a high-pressure uv preionized CO laser was measured for pressures to 14 atm. The data show an ~10% increase in the gain of the P branch of the 961-cm (00 degrees 1) - (10 degrees 0) band which is attributed to the overlapping 927-cm 011- (110) band. The measured gain was shown t ... [Appl. Phys. Lett. 26, 523 (2008)] published Tue Sep 2, 2008.
Quasi-cw laser emission from the second positive band of nitrogen
S. N. Suchard, L. Galvan, and D. G. Sutton
Experimental results are presented for the observation of a second positive nitrogen laser that has a pulse length much longer than the radiative lifetime of the upper laser level. Preliminary measurements of the temporal behavior of this laser indicate that it was operating in a quasi-continuous-wa ... [Appl. Phys. Lett. 26, 521 (2008)] published Tue Sep 2, 2008.
GaAs-AlGaAs double heterostructure lasers with taper-coupled passive waveguides
F. K. Reinhart and R. A. Logan
Taper-coupled laser structures suitable for integrated optics applications were grown by a liquid phase epitaxy process. Reduced threshold current densities, j=6.3 kA/cm [mu]m, and external differential quantum efficiencies eta as high as 28% were measured with nominally undoped n-type active layers ... [Appl. Phys. Lett. 26, 516 (2008)] published Tue Sep 2, 2008.
Observations of small-signal gain in high-pressure pulsed CO electric discharge laser
M. J. W. Boness and R. E. Center
Measurements are reported of the magnitude and temporal behavior of small-signal gain in a pulsed high-pressure carbon monoxide electric discharge laser. These are compared with predictions derived from kinetic modeling calculations. Maximum gain of 4.5%/cm was measured on the 9P (10) and 8P (10) tr ... [Appl. Phys. Lett. 26, 511 (2008)] published Tue Sep 2, 2008.
Extension of absolute frequency measurements to 148 THz: Frequencies of the 2.0- and 3.5-mu m Xe laser
D. A. Jennings, F. R. Petersen, and K. M. Evenson
Absolute infrared frequency measurement has been extended to 148 THz (the highest frequency ever directly measured) with measurement of the two strong cw laser lines of Xe. The frequencies were synthesized with stabilized CO and 3.39-[mu]m He-Ne lasers and mixed on a W-Ni point-contact diode. The me ... [Appl. Phys. Lett. 26, 510 (2008)] published Tue Sep 2, 2008.
Transverse self-sustained discharge CO[sub 2] laser
David B. Cohn
A scalable transverse self-sustained discharge maintained between an array of flow-stabilized cathodes and a common anode has demonstrated specific input powers of 800 W/g/sec and power densities of 100 W/cm per cathode for CO-N-He mixtures at pressures of 5070 Torr. Optical extraction at 15% effici ... [Appl. Phys. Lett. 26, 508 (2008)] published Tue Sep 2, 2008.
Two-photon stimulated emission and pulse amplification
Horace P. Yuen
Threshold conditions are given for the sustained operation of standing-wave and long-pulse traveling-wave two-photon lasers. Pulse shortening in long-pulse two-photon amplification, a behavior absent in the one-photon case, is also demonstrated analytically. ... [Appl. Phys. Lett. 26, 505 (2008)] published Tue Sep 2, 2008.
High-efficiency multiply pulsed copper vapor laser utilizing copper chloride as a lasant
Che J. Chen and Gary R. Russell
A copper vapor laser operating at a wavelength of 5106 A and a pulse repetition rate up to 30 000 pulses/sec has been constructed and investigated. The best results obtained to date are as follows: energy and power density of 35 [mu]J cm and 1.7 kW cm; pulsewidth 20 nsec; average density 0.7 W cm; l ... [Appl. Phys. Lett. 26, 504 (2008)] published Tue Sep 2, 2008.
Spatially coherent radiation from an array of GaAs lasers
Elisabeth M. PhilippRutz
Spatially coherent radiation from a monolithic array of three homostructure GaAs lasers is reported. The three lasers, with their mirror faces antireflection coated, are operated in external optical cavity built of spherical lenses and plane mirrors. The spatially coherent beam formation makes use o ... [Appl. Phys. Lett. 26, 475 (2008)] published Tue Sep 2, 2008.
Transmission properties of a low - loss near - parabolic - index fiber
L. G. Cohen, P. Kaiser, J. B. Mac Chesney, P. B. O'Connor, and H. M. Presby
Pulse dispersion, refractiveindex profile, and loss measurements were made on a lowloss gradedindex optical fiber fabricated by a chemical vapor deposition technique. The transmission loss spectra had a minimum value of 3.8 dB/km at 1.06[mu]m wavelength. The core refractive index had a powerlaw prof ... [Appl. Phys. Lett. 26, 472 (2008)] published Tue Sep 2, 2008.
Push - pull thin - film optical modulator
J. C. Webster and F. Zernike
An electrooptic amplitude modulator was made by placing two channeldefined waveguide phase modulators in the legs of a Jamin interferometer. Using a novel detection method, modulation was observed up to 1.8 GHz, although the rolloff in the modulator response started at about 750 MHz. Full amplitude ... [Appl. Phys. Lett. 26, 465 (2008)] published Tue Sep 2, 2008.
Laser oscillation from quantum states in very thin GaAs - Al[sub 0.2]Ga[sub 0.8]As multilayer structures
J. P. van der Ziel, R. Dingle, R. C. Miller, W. Wiegmann, and W. A. Nordland, Jr.
We report optically pumped laser oscillation from multilayer heterostructures consisting of alternating layers of GaAs and AlGaAs. Very thin GaAs layers (50500 A) exhibit onedimensional bound states above the band gap of bulk GaAs. The laser oscillation occurs at energies which are slightly below th ... [Appl. Phys. Lett. 26, 463 (2008)] published Tue Sep 2, 2008.
Interferometric tuning of a 15 - atm CO[sub 2] laser
F. O'Neill and W. T. Whitney
Efficient controlled frequency narrowing and tuning of a highpower 15atm electronbeamcontrolled CO laser has been achieved using a FabryPerot etalon as a dispersive element in the laser resonator. Tuning has been accomplished over the free spectral range of the etalon (~2.3 cm) giving a laser linewi ... [Appl. Phys. Lett. 26, 454 (2008)] published Tue Sep 2, 2008.
Spin resonance matching in tunable far - infrared generation by optical mixing via spin - flip transitions
V. T. Nguyen and T. J. Bridges
The generation of continuously tunable farinfrared radiation by difference frequency mixing, using the electron spin nonlinearity and a spinflip laser, has been significantly improved. This has been done by tuning the sharp spin resonance of the mixer to the difference frequency by correct placement ... [Appl. Phys. Lett. 26, 452 (2008)] published Tue Sep 2, 2008.
A 3400 - [A-ring] p - terphenyl dye laser pumped by a CO[sub 2] - laser - produced plasma
W. T. Silfvast and O. R. Wood II
Ultraviolet radiation from a xenon plasma produced with a highpressure pulsed CO laser has been used to pump a 3400A pterphenyl dye laser. Potential advantages of laserporduced plasmas over electrical flashlamps as pumping sources for uv dye lasers are discussed. ... [Appl. Phys. Lett. 26, 447 (2008)] published Tue Sep 2, 2008.
Completeley optical coincidence logic employing a dye laser
E. J. Johnson, L. A. Riseberg, A. Lempicki, and H. Samelson
We report the theory and experimental demonstration of a laser device which performs the functions of binary arithmetic completely optically. The coincidence circuit employs polarization coding of the logic variables and is based upon the bistable polarization behavior of a dye laser in a birefringe ... [Appl. Phys. Lett. 26, 444 (2008)] published Tue Sep 2, 2008.
Enhanced nonlinear optical effects in rotationally twinned crystals
C. F. Dewey, Jr. and L. O. Hocker
We have produced continuously tunable infrared radiation between 4 and 21 [mu]m by mixing the outputs of a ruby laser and a rubypumped dye laser in a single rotationally twinned ZnSe crystal. The peak output power of 5 W at 4 [mu]m is approximately 250 times larger than the power obtained from an un ... [Appl. Phys. Lett. 26, 442 (2008)] published Tue Sep 2, 2008.
Continuously tunable submillimeter wave source
M. A. Piestrup, R. N. Fleming, and R. H. Pantell
A method for spanning the 1001000[mu] portion of the spectrum with continuously tunable coherent radiation is described. The approach is based upon laser light scattering from the longwavelength side of the Asymmetry soft mode in LiNbO. In contrast with other techniques, this method uses a single fi ... [Appl. Phys. Lett. 26, 418 (2008)] published Tue Sep 2, 2008.
Thin - film optical magnetic mode converters
R. D. Henry
A new type of thinfilm magnetooptic mode converter is described which has the potential to perform both reciprocal and nonreciprocal mode conversion. As a reciprocal mode converter, the fabrication of the device is straightforward and presents some features not available in previous designs. The sam ... [Appl. Phys. Lett. 26, 408 (2008)] published Tue Sep 2, 2008.
LiNb[sub x]Ta[sub 1 - x]O[sub 3] optical waveguiding layer in LiTaO[sub 3] fabricated by diffusion of LiNbO[sub 3] sputtered film
Makoto Minakata, Juichi Noda, and Naoya Uchida
Thermal diffusion of a rfsputtered LiNbO thin film into a LiTaO substrate has been investigated. By an appropriate choice of diffusion conditions, a singlemode waveguiding layer with the composition LiNbTaO has been fabricated. The refractiveindex change at the surface is about 0.9 x 10 for both n a ... [Appl. Phys. Lett. 26, 395 (2008)] published Tue Sep 2, 2008.
Ga[sub x]In[sub 1 - x]P - Ga[sub y]Al[sub 1 - y]As heterojunction close - confinement injection laser
G. Schul and P. Mischel
Heterojunction laser diodes with GaInP active layer have been fabricated from GaAsGaInPGa AlAsGaAs heterostructures made by liquid phase epitaxy from Garich and Inrich solutions. Stripegeometry lasers have been operated at 77 K with threshold current densities as low as 2500 A/cm with an emission wa ... [Appl. Phys. Lett. 26, 394 (2008)] published Tue Sep 2, 2008.
An aluminum/SiO[sub 2]/silicon - on - sapphire light valve matrix for projection displays
J. Guldberg, H. C. Nathanson, D. L. Balthis, and A. S. Jensen
A new electronbeamaddressed light valve structure has been tested which is composed of a large array of 0.002 x 0.002in. 3000Athick aluminized silicon dioxide electrostatically deflectable squares, suspended by a centrally located 45[mu]mtall silicon post over a transparent sapphire substrate. The d ... [Appl. Phys. Lett. 26, 391 (2008)] published Tue Sep 2, 2008.
Subnanosecond tunable dye laser pulse generation by controlled resonator transients
Chinlon Lin and C. V. Shank
A general technique for subnanosecond pulse generation from laserpumped dye lasers is described. The technique makes use of the resonator transients. These transients are in the form of damped relaxation oscillation and their durations can be controlled by proper choices of photon cavity decay time ... [Appl. Phys. Lett. 26, 389 (2008)] published Tue Sep 2, 2008.
Tapered section of multimode cladded fibers as mode filters and mode analyzers
Takeshi Ozeki, Takao Ito, and Toshifumi Tamura
Mode filtering characteristics of biconical tapers in multimode fibers were examined. The insertion loss of a biconical taper for the HE mode is 0.2 dB and the rejection ratios for higherorder modes are more than 20 dB. The mode conversion in a biconical taper is sufficiently small except for the HE ... [Appl. Phys. Lett. 26, 386 (2008)] published Tue Sep 2, 2008.
Rotational coupling and laser dynamics in TE CO[sub 2] lasers
E. A. Ballik, B. K. Garside, and J. Reid
A model of the gainswitched TE CO laser is presented which explicitly includes rotational relaxation within the sublevels of the 10.4[mu] laser band. Careful comparison with experiment is made employing a Qswitched cavity, and it is shown that rotational coupling dominates the laser dynamics at pres ... [Appl. Phys. Lett. 26, 380 (2008)] published Tue Sep 2, 2008.
Phase - matched second harmonic generation in a liquid - filled waveguide
B. F. Levine, C. G. Bethea, and R. A. Logan
Phasematched second harmonic generation in a nitrobenzenefilled waveguide has been accomplished by using a periodic electrode to modulate the nonlinear susceptibility. ... [Appl. Phys. Lett. 26, 375 (2008)] published Tue Sep 2, 2008.
Air - combustion product N[sub 2] - CO[sub 2] electric laser
D. H. DouglasHamilton, G. W. Sutton, L. Westra, and R. S. Lowder
Efficient electronbeam sustainer CO laser action has been obtained in H : N : CO mixtures, using H as COnu deactivant. This opens up the possibility of using a fuelrich hydrocarbon combustion product as a readily obtained laser gas mixtures, since such a mixture can be generated containing free H. E ... [Appl. Phys. Lett. 26, 373 (2008)] published Tue Sep 2, 2008.
Thickness dependence of acousto - optic diffraction efficiency in ZnO - film optical waveguides
J. Kushibiki, H. Sasaki, N. Chubachi, N. Mikoshiba, and K. Shibayama
The thickness dependence of the efficiency of the Bragg diffraction between the same optical modes (TE-->TE, TM-->TM) by acoustic surface waves in ZnOfilm optical waveguides is investigated at an acoustic frequency of 130 MHz and a film thickness from 0.6 to 8.0 [mu]m. It is observed that the effici ... [Appl. Phys. Lett. 26, 362 (2008)] published Tue Sep 2, 2008.
Frequency doubling in KB[sub 5]O[sub 8] [center-dot] 4H[sub 2]O and NH[sub 4]B[sub 5]O[sub 8] [center-dot] 4H[sub 2]O to 217.3 nm
C. F. Dewey, Jr., W. R. Cook, Jr., R. T. Hodgson, and J. J. Wynne
We have produced tunable phase-matched second-harmonic radiation in a KBO4HO crystal between 217.3 and 234.5 nm. Phase matching was achieved by crystal rotation. We also studied frequency doubling in NHBO4HO. ... [Appl. Phys. Lett. 26, 714 (2008)] published Tue Sep 2, 2008.
Optical bends and rings fabricated by preferential etching
Cheng-Chung Tseng, Dan Botez, and Shyh Wang
We have applied the preferential etching technique to the fabrication of optical bends and rings. Nearly perfect smooth waveguide walls formed by crystalline planes can still be obtained in the curved section. Applications of such preferentially etched optical bends and rings in integrated optics ar ... [Appl. Phys. Lett. 26, 699 (2008)] published Tue Sep 2, 2008.
cw fiber laser of NdLa pentaphosphate
H. P. Weber, P. F. Liao, B. C. Tofield, and P. M. Bridenbaugh
cw operation at 1.051 [mu]m of a waveguide laser consisting of a crystalline fiber of NdLaPO, 12 x 12 [mu]m in cross section and 0.68 mm in length, is reported. When longitudinally pumped with a Kr ion laser at 752.5 nm the room-temperature laser threshold was less than 10-mW absorbed power. ... [Appl. Phys. Lett. 26, 692 (2008)] published Tue Sep 2, 2008.
TeO[sub 2] anisotropic Bragg light deflector without midband degeneracy
T. Yano, M. Kawabuchi, A. Fukumoto, and A. Watanabe
An advanced acousto-optic light deflector has been designed using the acoustic shear wave traveling slightly off the [110] axis in TeO. The midband mode degeneracy reported by Warner et al., which decreases the diffracted light intensity, has been shifted off from the active frequency region. A line ... [Appl. Phys. Lett. 26, 689 (2008)] published Tue Sep 2, 2008.
Third harmonic generation in phase-matched alkali metal vapors
D. M. Bloom, G. W. Bekkers, J. F. Young, and S. E. Harris
We report improvements in conversion efficiency for third harmonic generation in sodium and rubidium vapor. 30-psec pulses of radiation at 1.064 [mu]m have been converted to 0.3547 [mu]m with an energy conversion efficiency of 10%. Factors limiting conversion efficiency are discussed. ... [Appl. Phys. Lett. 26, 687 (2008)] published Tue Sep 2, 2008.
Optical waveguides in LiNbO[sub 3] by ion exchange technique
Manhar L. Shah
Optical waveguides produced in LiNbO by immersing the x-cut plates into molten AgNO are reported. An increase in the extraordinary refractive index of LiNbO at the surface of the plate due to silver exchange is estimated to be 0.12. In such a waveguide, optical losses of 6 dB/cm were measured for th ... [Appl. Phys. Lett. 26, 652 (2008)] published Tue Sep 2, 2008.
Low-threshold cw LiNdP[sub 4]O[sub 12] laser
S. R. Chinn and H. Y-P. Hong
We have studied cw room-temperature lasing behavior of LiNdPO. A threshold of 360-[mu]W optical excitation power at 0.582-[mu]m wavelength was measured, with 18% power conversion efficiency to 1.048-[mu]m radiation at 1-mW output. The crystal structure is found to be monoclinic (C2/c) rather than or ... [Appl. Phys. Lett. 26, 649 (2008)] published Tue Sep 2, 2008.
Astigmatism and coma-free prism dye ring laser
Gerd Marowsky
The characteristics of two prism ring lasers for cw operation have been experimentally studied. With improved compensation for aberrations due to astigmatism and coma, cw ring lasers operated in the traveling-wave mode provide high output efficiency, stable narrow bandwidth in multimode and single-m ... [Appl. Phys. Lett. 26, 647 (2008)] published Tue Sep 2, 2008.
Low-divergence beams from grating-coupled composite guide heterostructure GaAlAs diode lasers
R. D. Burnham, D. R. Scifres, and W. Streifer
Room-temperature operation of a new grating-coupled heterostructure diode laser is reported. The laser contains two GaAs layers separated by a GaAlAs layer. One of the GaAs layers is electrically pumped, whereas the other is corrugated. Light is distributed over both layers and the grating couples o ... [Appl. Phys. Lett. 26, 644 (2008)] published Tue Sep 2, 2008.
GaAs electro-optic channel-waveguide modulator
J. C. Campbell, F. A. Blum, and D. W. Shaw
We describe a GaAs electro-optic channel waveguide which can be used as a high-speed modulator with a potential bandwidth of 1 GHz. A narrow Schottky-barrier strip permits beam trapping to be controlled by an applied voltage. Ninety-five percent amplitude modulation has been obtained with a minimum ... [Appl. Phys. Lett. 26, 640 (2008)] published Tue Sep 2, 2008.
Diffusion kinetics and optical quality in LiNbO[sub 3]-LiTaO[sub 3] optical waveguides
G. Y. Chin, A. A. Ballman, P. K. Tien, and S. Riva-Sanseverino
Diffusivity measurements have been made at 1000, 1100, and 1200 degrees C on LiNbO-LiTaO single-crystal thin films prepared by melt-phase and liquid-phase epitaxy. The interdiffusion coefficient is determined to be D~5 x 10 exp[40(kcal/mol)/RT] cm sec. In addition, we found substantial reduction in ... [Appl. Phys. Lett. 26, 637 (2008)] published Tue Sep 2, 2008.
Far-infrared superradiant laser action in methyl fluoride
D. E. Evans, L. E. Sharp, B. W. James, and W. A. Peebles
Submillimeter laser pulses exceeding 1-MW power have been generated superradiantly in CHF gas pumped by 200 MW of 9.55-[mu] CO TEA laser radiation. When far-infrared output was restricted to operation on the 496 line alone, 0.5 MW was achieved within a bandwidth of 100 MHz. ... [Appl. Phys. Lett. 26, 630 (2008)] published Tue Sep 2, 2008.
Effective absorption for thermal blooming due to aerosols
C. H. Chan
Thermal blooming on laser propagation due to the presence of aerosol particles is considered. Emphasis is placed on the derivation of an effective absorption coefficient alpha(t), where alpha(t) corresponds to that part of aerosol absorption which heats up the air only. Becuase of the small but nonv ... [Appl. Phys. Lett. 26, 628 (2008)] published Tue Sep 2, 2008.
Table-top Ar-N[sub 2] laser
E. R. Ault
A compact ArN excitation transfer laser pumped by a coaxial electron gun is demonstrated. This laser emits a 40-ns, 300-kW pulse at a nominal repetition rate of 1 HZ. With 45 J of energy delivered to the electron gun, 12 mJ of laser output at 3577 A is obtained. A 2.8% laser efficiency is estimated ... [Appl. Phys. Lett. 26, 619 (2008)] published Tue Sep 2, 2008.
Comment on ''Dynamic model of high-pressure rare-gas excimer lasers''
J. B. Gerardo and A. Wayne Johnson
The model of the rare-gas excimer lasers that was recently proposed by Werner et al. is shown to be inconsistent with some experimental measurements of xenon dimer laser gain and laser intensity. Measurements of the laser intensity and laser-medium gain of a xenon dimer laser show that the laser pul ... [Appl. Phys. Lett. 26, 582 (2008)] published Tue Sep 2, 2008.
Optimum diffusion condition in the fabrication of a plastic lenslike medium
K. Iga, K. Yokomori, and T. Sakayori
The optimum fabrication condition has been found in the preparation of a plastic lenslike medium which has a parabolic dielectric constant distribution. The maximum possible value of the focusing constant g=0.21 mm was obtained for diallyl isophthalatemethylmethacrylate combination with a rod radius ... [Appl. Phys. Lett. 26, 578 (2008)] published Tue Sep 2, 2008.
Nondestructive refractive-index profile measurements of clad optical fibers
M. E. Marhic, P. S. Ho, and M. Epstein
An interferometric method in conjunction with Abel inversion is used to precisely measure the index of refraction profile of clad optical fibers without perturbing them. The sample is immersed in index-matching fluid, so that fiber index variations cause only small phase shifts for rays propagating ... [Appl. Phys. Lett. 26, 574 (2008)] published Tue Sep 2, 2008.
Very rapid tuning of cw dye laser
John M. Telle and C. L. Tang
A method is described which allows the cw dye laser to be tuned over hundreds of angstroms on a nanosecond time scale in spite of the 100-nsec cavity decay and buildup time. Data are provided to verify the proposed method. This tuning rate is fast enough to do, for example, chemical kinetic studies ... [Appl. Phys. Lett. 26, 572 (2008)] published Tue Sep 2, 2008.
Linear and nonlinear optical properties of lithium perchlorate trihydrate LiClO[sub 4] [center-dot] 3H[sub 2]O
J. G. Bergman, Denise Williams, G. R. Crane, and R. N. Storey
Lithium perchlorate trihydrate (LiClO3HO) is shown to be nearly noncritically phase matchable for a 0.53-[mu] pump, generating ultraviolet at 0.265 [mu]. The water white crystals are transparent out to 2100 A. The nonlinear coefficients d, d, and d are (0.79, 0.68, 0.77) x d(SiO), respectively. ... [Appl. Phys. Lett. 26, 571 (2008)] published Tue Sep 2, 2008.
Conversion of cw light into a train of subnanosecond pulses using frequency modulation and the dispersion of a near-resonant atomic vapor
J. E. Bjorkholm, E. H. Turner, and D. B. Pearson
Sinusoidally frequency-modulated cw laser light is converted into a train of repetitive short pulses by passing it through a nearly resonant atomic vapor. Using a 200-MHz modulation frequency and sodium vapor, pulses as short as 240 psec, having peak powers of 6.3 times the input power, have been ob ... [Appl. Phys. Lett. 26, 564 (2008)] published Tue Sep 2, 2008.
A new waveguide switch/modulator for integrated optics
W. E. Martin
A waveguide optical switch and/or modulator device is described that uses a single-mode waveguide version of the Mach-Zehnder interferometer. A mode selective branching waveguide is used for switching, and modulation can be accomplished without external polarizers in single-mode waveguides. The oper ... [Appl. Phys. Lett. 26, 562 (2008)] published Tue Sep 2, 2008.
High-pressure chemical waveguide laser
T. O. Poehler, R. E. Walker, and J. W. Leight
The exothermic chain reactions between deuterium and fluorine have been used to produce laser emission from carbon dioxide in a high-pressure chemical waveguide laser. Chemical chain reactions initiated by flash photolysis of this system produced 10.6-[mu]m radiation from a 3-mm-diam laser tube havi ... [Appl. Phys. Lett. 26, 560 (2008)] published Tue Sep 2, 2008.
Influence of fluid-dynamic phenomena on the occurrence of constriction in cw convection laser discharges
W. J. Wiegand and William L. Nighan
The influence of gas residence time, turbulence, and discharge uniformity on the electrical power density threshold for glow constriction has been investigated for conditions typical of high-power cw convection-cooled molecular lasers. Relatively independent evaluation of the effect of these propert ... [Appl. Phys. Lett. 26, 554 (2008)] published Tue Sep 2, 2008.
Taper couplers for GaAs - Al[sub x]Ga[sub 1 - x]As waveguide layers produced by liquid phase and molecular beam epitaxy
J. L. Merz, R. A. Logan, W. Wiegmann, and A. C. Gossard
Growth techniques and passive evaluation of tapered waveguide light couplers produced by LPE and MBE are reported. Coupling efficiencies approaching 100% for the transfer of light from a GaAs layer to a layer of AlGaAs are observed for MBE tapers, and tapers fabricated by LPE allow ~50% coupling, su ... [Appl. Phys. Lett. 26, 337 (2008)] published Tue Sep 2, 2008.
Simple TEA laser geometry with volumetric photoionization
B. J. Reits and A. H. M. Olbertz
A weak uv source conditions a CO laser gas discharge with the aid of the seed gas trinpropylamine. Rich mixtures and high input energy densities can be used, resulting in extremely high peak powers. ... [Appl. Phys. Lett. 26, 335 (2008)] published Tue Sep 2, 2008.
High - power mode - locked TEA CO[sub 2] laser using an unstable resonator
P. E. Dyer and D. J. James
A passively modelocked TEA CO laser has been operated with an unstable resonator, and modelocked trains with peak powers >~150 MW, together with near diffractionlimited beams, have been obtained. Single axial mode operation at a power level of 14 MW has also been achieved. These results represent a ... [Appl. Phys. Lett. 26, 331 (2008)] published Tue Sep 2, 2008.
Diffused two - dimensional optical waveguides in GaAs
E. Garmire, D. F. Lovelace, and G. H. B. Thompson
TE and TE optical waveguide modes have been observed in GaAs stripe pn junctions produced by zinc diffusion through SiO masks into ntype substrates. Excellent agreement was found between guided light profiles at 1.15 [mu]m and those predicted on the basis of refractive index profiles given by the fr ... [Appl. Phys. Lett. 26, 329 (2008)] published Tue Sep 2, 2008.
Single - crystal fiber optical devices: A Nd:YAG fiber laser
C. A. Burrus and J. Stone
Singlecrystal fibers of Nd:YAG have been grown in diameters as small as, but not limited to, 50 [mu]m by a pedestal growth (modified zone melting) technique. Roomtemperature cw laser operation has been achieved with 0.51cmlong samples. The method is directly applicable to the growth of singlecrystal ... [Appl. Phys. Lett. 26, 318 (2008)] published Tue Sep 2, 2008.
Optically pumped vibrational transition laser in OCS
H. R. Schlossberg and H. R. Fetterman
Laser oscillation between vibrational states has been demonstrated at 19 [mu]m in OCS by optical pumping on the nu overtone with a CO TEA laser. Analysis of the molecular kinetics indicates this technique to be general and capable of yielding many highpower (>~1000 W) laser lines below 50 [mu]m. ... [Appl. Phys. Lett. 26, 316 (2008)] published Tue Sep 2, 2008.
Anomalous dispersion effects on pulse propagation in high - pressure CO[sub 2] amplifiers
G. T. Schappert and M. J. Herbst
We have measured the time delay of a P (20) short pulse propagating through a highpressure CO amplifier under smallsignalgain conditions. The reduced velocity agrees with the group velocity, which is about 0.92c. The effect is proportional to the small signal gain divided by the linewidth. ... [Appl. Phys. Lett. 26, 314 (2008)] published Tue Sep 2, 2008.
Transversely pumped LNP laser performance
Kenju Otsuka and Tomoaki Yamada
We report on quaiscontinuous laser oscillation of lithium neodymium tetraphosphate of 2mm length pumped transversely with a chopped argon laser. The roomtemperature threshold was 95 mW and the slope efficiency was 3.7%. The threshold of transverse pumping was 2.5 times that of longitudinal pumping; ... [Appl. Phys. Lett. 26, 311 (2008)] published Tue Sep 2, 2008.
Electrically based spectral power measurements through use of a tunable cw laser
Jon Geist, Bruce Steiner, Russell Schaefer, Edward Zalewski, and Antonio Corrons
A new approach to radiant power measurements is described. A continuously tunable cw dye laser was used to measure the absolute spectral response of a silicon photodiode and narrow bandpass filter by comparison with an electrically calibrated pyroelectric detector. The filtered photodetector was the ... [Appl. Phys. Lett. 26, 309 (2008)] published Tue Sep 2, 2008.
Optical directional couplers and grating couplers using a new high - resolution photolocking material
W. J. Tomlinson, H. P. Weber, C. A. Pryde, and E. A. Chandross
Lowloss singlemode optical waveguides (~4 x 1.5 [mu]m), optical directional couplers, and grating couplers were made by the photolocking process in a new highresolution system using naphthalenethiol as the dopant. Index changes of up to 1.3% and optical losses typically 0.3 dB/cm were achieved (at l ... [Appl. Phys. Lett. 26, 303 (2008)] published Tue Sep 2, 2008.
Electro - optic intensity modulation in LiTaO[sub 3] ridge waveguide
Juichi Noda, Naoya Uchida, Makoto Minakata, Tadashi Saku, Shoichi Saito et al.
A narrow rectangular ridge for 24 [mu]m (width of the top) x 6 [mu]m (height) x 5.4 mm (length) has been formed on Cudiffused xplate LiTaO using the sputteretching technique. The intensity modulation of the optical wave confined in the ridge has been made up to 1 GHz with a halfwave voltage of 253 ... [Appl. Phys. Lett. 26, 298 (2008)] published Tue Sep 2, 2008.
Optical intensity modulator with three - dimensional waveguide
Shingo Uehara, Kiichi Takamoto, Seitaro Matsuo, and Yoshiharu Yamauchi
A LiTaO optical waveguide modulator, in which a laser beam is confined in both transverse dimensions, has been fabricated. The threedimensional waveguiding operation was achieved by using an ionetched thin core slab and a slit metal cladding. Waveguide porperties for 0.633 and 1.15[mu]m laser beams ... [Appl. Phys. Lett. 26, 296 (2008)] published Tue Sep 2, 2008.
Onset of convection due to horizontal laser beams
R. D. Boyd and C. M. Vest
When a horizontal cw laser beam is suddenly turned on in a quiescent isothermal fluid there is a delay time t during which thermal blooming is governed by absorption of radiation and thermal conduction. For t>~t, free convection becomes a significant factor. t is determined by an approximate quasist ... [Appl. Phys. Lett. 26, 287 (2008)] published Tue Sep 2, 2008.
Coherent selective erasure of superimposed volume holograms in LiNbO[sub 3]
J. P. Huignard, J. P. Herriau, and F. Micheron
Selective erasure of superimposed holograms recorded in Fedoped LiNbO is reported. This process consists of photoinducing complementary refractive index changes which cancel the previously recorded changes. It can be applied to any stacked hologram in the crystal volume as well as to any part of ... [Appl. Phys. Lett. 26, 256 (2008)] published Tue Sep 2, 2008.
Defect structure of degraded heterojunction GaAlAs - GaAs lasers
P. W. Hutchinson, P. S. Dobson, S. O'Hara, and D. H. Newman
Transmission electron microscopy has been used to study the defects associated with the degradation of broadcontact geometry doubleheterostructure lasers. Two different types of dislocation networks have been observed close to the active region of the degraded device having Burgers vectors of (a/2) ... [Appl. Phys. Lett. 26, 250 (2008)] published Tue Sep 2, 2008.
Reliability of DH GaAs lasers at elevated temperatures
R. L. Hartman and R. W. Dixon
Data from accelerated aging tests on continuously operating stripegeometry doubleheterostructure GaAs lasers are presented. By extrapolating data obtained in drynitrogen ambients at temperatures of 90, 70, and 50 degrees C, it is concluded that continuous roomtemperature operation of these devices ... [Appl. Phys. Lett. 26, 239 (2008)] published Tue Sep 2, 2008.
Improved optical quality of AgGaS[sub 2]
H. Matthes, R. Viehmann, and N. Marschall
Single crystals of AgGaS for nonlinear optical applications were grown by the BridgmanStockbarger technique. It was possible to prepare 0.5cm cubes free of lamellar twins from the central region of the boules. Roomtemperature absorption of asgrown crystals was below 0.3 cm through the whole transmis ... [Appl. Phys. Lett. 26, 237 (2008)] published Tue Sep 2, 2008.
Optically pumped cw InSb lasers for NO spectroscopy
A. S. Pine and N. Menyuk
Tunable cw laser emission has been obtained near 5.3 [mu]m from InSb samples at ~10 K optically pumped with GaAs, Nd : YAG, and CO lasers. InSb laser thresholds have been determined as a function of incident pump wavelength and applied magnetic fields from 0 to 9.5 kOe. Temperature and magnetic fiel ... [Appl. Phys. Lett. 26, 231 (2008)] published Tue Sep 2, 2008.
Nonchemical HF pulse laser pumped by e - beam - sustained discharge
R. M. Osgood Jr. and D. L. Mooney
Experiments with a pulsed dischargepumped (nonchemical) HF laser are described. The laser discharge is sustained with a cold cathode electron beam gun. An output power of 8 kW/cm in a 2.5[mu]sec pulse length is obtained. Several observations regarding the laser mechanism are made. ... [Appl. Phys. Lett. 26, 201 (2008)] published Tue Sep 2, 2008.
Double - discharge arrangement for cw electrical excitation of supersonic flows
J. H. Blom and R. K. Hanson
A simple doubledischarge electrode arrangement for the cw excitation of supersonic molecular gas flows is described. Stable discharges in N and N/CO mixtures, with E/N of 2.02.5 x 10 V cm and a power loading of 2.6 x 10 eV/molecule, were achieved. ... [Appl. Phys. Lett. 26, 190 (2008)] published Tue Sep 2, 2008.
Observation of laser action in CO gas excited only by fission fragments
D. A. McArthur and P. B. Tollefsrud
We report the first clear observation of laser action in a medium excited only by fission fragments. CO gas at 77 degrees K and pressure [approximate]100 Torr was excited by fission fragments from enriched UO foils, which were irradiated with neutrons from a fastburst reactor. The laser signal was ... [Appl. Phys. Lett. 26, 187 (2008)] published Tue Sep 2, 2008.
Optical aging characteristics of borosilicate clad fused silica core fiber optical waveguides
I. Camlibel, D. A. Pinnow, and F. W. Dabby
Very low transmission loss fiber optical waveguides have been developed during the past two years which have pure fused silica cores surrounded by borosilicate glass claddings. A recent study of the binary borosilicate glass system revealed that the low refractive index values which can be achieved ... [Appl. Phys. Lett. 26, 185 (2008)] published Tue Sep 2, 2008.
Multiple storage and erasure of fixed holograms in Fe - doped LiNbO[sub 3]
D. L. Staebler, W. J. Burke, W. Phillips, and J. J. Amodei
Holograms were recorded and fixed simultaneously in heated (~160 degrees C) crystals of Fedoped LiNbO. With this procedure the crystals have the erase/write asymmetry required for multiple storage of highdiffractionefficiency holograms. Five hundred fixed holograms, each with more than 2.5% diffract ... [Appl. Phys. Lett. 26, 182 (2008)] published Tue Sep 2, 2008.
A novel technique for measuring small absorption coefficients in semiconductor infrared laser window materials
A. V. Nurmikko
A novel technique for measuring small absorption coefficients in semiconductor infrared laser window materials is presented. The method consists of optically measuring small shifts at the fundamental absorption edge when a thin sample wafer is heated by an incident laser beam. Experimental results a ... [Appl. Phys. Lett. 26, 175 (2008)] published Tue Sep 2, 2008.
Induced focusing and defocusing of optical beams via a Raman - type nonlinearity
Adelbert Owyoung
Using a 5.7MW singlemode ruby laser pulse at an intensity of 100 MW/cm through a 10cmlong cell of benzene, we report the experimental observation of the induced focusing and defocusing of an externally generated Stokes probe beam on the high and lowfrequency side of the 992cm Raman line, respectivel ... [Appl. Phys. Lett. 26, 168 (2008)] published Tue Sep 2, 2008.
cw Raman fiber amplifier
J. Stone
cw Raman amplification has been observed in a hollow fused silica fiber, inside diameter 5 [mu]m, 5 m long, filled with benzene. Using a krypton laser pump, amplification of the 992cm Stokes Raman line has been obtained at pump wavelengths 5682, 6471, and 7525 A. The pump powers determined by measur ... [Appl. Phys. Lett. 26, 163 (2008)] published Tue Sep 2, 2008.
Porous - wall BeO capillary waveguide laser
A. Papayoanou and A. Fujisawa
Smallbore capillary tubes exhibit very high optical gains and saturation intensities in flowing gas CO systems. However, these parameters may vary greatly in the axial direction due to the nonuniform axial pressure distribution. Use of porouswall BeO capillary tubes makes it possible to attain a mor ... [Appl. Phys. Lett. 26, 158 (2008)] published Tue Sep 2, 2008.
Theory of the dispersive modulator
D. Grischkowsky and M. M. T. Loy
The recent observations by Loy of amplitude modulation and compression of infrared laser pulses caused by passage through the dispersive modulator (a cell containing dilute NH vapor with a Starkmodulated resonant frequency) are explained. It is shown that there is a formal equivalence between (i) th ... [Appl. Phys. Lett. 26, 156 (2008)] published Tue Sep 2, 2008.
Storage of optical patterns in a zinc - oxide - on - silicon surface wave convolver
K. L. Davis
A monolithic zincoxideonsilicon surface wave convolver has been used to image optical patterns and store them for long periods of time. A light pattern is stored by projecting it onto a semitransparent top convolver electrode which has an applied negative dc bias. Slow states associated with the zin ... [Appl. Phys. Lett. 26, 143 (2008)] published Tue Sep 2, 2008.
A dispersive modulator
Michael M. T. Loy
Amplitude modulation and temporal compression of 10[mu] light at a frequency up to 80 MHz were demonstrated using a dispersive molulatora NH vapor cell with a nearresonant timedependent transition frequency controlled externally via the Stark effect. The peak output intensity was observed to be high ... [Appl. Phys. Lett. 26, 99 (2008)] published Tue Sep 2, 2008.
Energy velocity and effective gain in distributed - feedback lasers
Shyh Wang
Here, we establish a relation G = gv/v between the effective gain coefficient G in a periodic medium (for a Bloch wave) and the ordinary gain coefficient g in a corresponding uniform medium (for an ordinary plane wave). In distributedfeedback (DFB) lasers, G is greater (or smaller) than g because th ... [Appl. Phys. Lett. 26, 89 (2008)] published Tue Sep 2, 2008.
Resonance self - absorption in CO lasers
W. B. Lacina and G. L. McAllister
Resonance selfabsorption from overlapping lines in a CO laser medium may be an important pressuredependent mechanism for theoretical analysis, with possible impact on line selection and atmospheric propagation. Certain presently unexplained discrepancies relating to transient time scale, spectral an ... [Appl. Phys. Lett. 26, 86 (2008)] published Tue Sep 2, 2008.
Power increase of N[sub 2] uv and ir lasers by addition of SF[sub 6]
Colin S. Willett and Daniel M. Litynski
The output power and energy per pulse of transversely excited (TE) nitrogen lasers operating well over threshold on the 0.3371[mu]m transition in the CPiBPi second positive system, and on nearinfrared transitions in the BPiASigma first positive system, have been found to be increased by more than 10 ... [Appl. Phys. Lett. 26, 118 (2008)] published Tue Sep 2, 2008.
Pulsed ion lasers excited by the pinch effect
J. Katzenstein and R. H. Lovberg
Previous experimental work has demonstrated strong laser action on the ionized lines of argon and xenon in pinch discharges in these gases. This laser action is correlated in time with the minimum contraction of the discharge. The laser output power, however, was found to saturate with bank voltage, ... [Appl. Phys. Lett. 26, 113 (2008)] published Tue Sep 2, 2008.
Observation of coherent anti - Stokes Raman scattering from liquid water
Irving Itzkan and Donald A. Leonard
The line shape of the coherent antiStokes (CAS) Raman band at 3200 cm in liquid water has been measured using two independent but synchronized pulsed nitrogen laser pumped dye lasers as excitation sources. The observed CAS spectral shape differs significantly from the corresponding classical Stokes ... [Appl. Phys. Lett. 26, 106 (2008)] published Tue Sep 2, 2008.
Erratum: Noncollinear acousto - optic filter with large angular aperture
I. C. Chang
... [Appl. Phys. Lett. 26, 71 (2008)] published Tue Sep 2, 2008.
Double heterostructure Pb[sub 1 - x]Sn[sub x]Te waveguides at 10.6 mu m
R. W. Ralston, J. N. Walpole, T. C. Harman, and I. Melngailis
Highopticalquality planar waveguides have been fabricated in the PbSnTe alloy system by molecular beam expitaxy. The structures consist of a 6[mu]mthick lowcarrierconcentration (<~4 x 10 cm) PbSnTe layer vacuum deposited on an ntype PbTe substrate followed by a second 0.5[mu]mthick epitaxial layer o ... [Appl. Phys. Lett. 26, 64 (2008)] published Tue Sep 2, 2008.
Anisotropic absorption saturation with picosecond pulses
C. V. Shank and E. P. Ippen
A new technique for measuring fast recovery of anisotropic absorption saturation is described. Picosecond pulses from a modelocked cw dye laser are used to induce and probe absorption saturation in the organic dye DODCI. Orientational relaxation of DODCI is measured as a function of solvent viscosit ... [Appl. Phys. Lett. 26, 62 (2008)] published Tue Sep 2, 2008.
Phase - matched harmonic generation in a laminar structure with wave propagation in the plane of the layers
J. P. van der Ziel
A technique for obtaining phasematched second harmonic generation using a finely layered structure with the radiation propagating parallel to the layers is analyzed. ... [Appl. Phys. Lett. 26, 60 (2008)] published Tue Sep 2, 2008.
Thermal instability in high - power laser discharges
J. H. Jacob and S. A. Mani
The thermal and acoustic instabilities that could possibly cause arcing in highpower pulsed and cw gas lasers have been investigated. A cubic dispersion relation is obtained from linearization of the coupled hydrodynamic and Ohmic equations in which the electrical conductivity is dependent on the ne ... [Appl. Phys. Lett. 26, 53 (2008)] published Tue Sep 2, 2008.
Pulsed double - heterostructure GaAs diode lasers in flexural and longitudinal vibrations
Rene Keller, Claude Voumard, and Horst Weber
The deformation behavior of pulsed doubleheterostructure diode lasers at both mirror and contact surfaces was investigated by means of an interferometric technique. The diodes, which were only supported by the pressure of a wire connection, showed at the end of a current pulse an elongation and defl ... [Appl. Phys. Lett. 26, 50 (2008)] published Tue Sep 2, 2008.
Highly collimated laser beams from electrically pumped SH GaAs/GaAlAs distributed - feedback lasers
D. R. Scifres, R. D. Burnham, and W. Streifer
Utilizing an electrically pumped singleheterostructure GaAs/GaAlAs distributedfeedback laser diode operating in fourth order we have obtained a highly collimated laser beam which is coupled out normal to the plane of the pn junction rather than through the cleaved end mirrors. This beam is found to ... [Appl. Phys. Lett. 26, 48 (2008)] published Tue Sep 2, 2008.
Heterostructure CdS[sub 1 - x]Se[sub x] - CdS surface lasers for integrated optics
Mitsuo Kawabe, Hideo Kotani, Kohzoh Masuda, and Susumu Namba
Heterostructure CdSSeCdS surface lasers which have a larger refractive index and a smaller band gap than CdS substrates were fabricated by vapor phase epitaxy and their laser characteristics at 80 K were studied by using a nitrogen gas laser excitation. The Se profiles which were deduced from the fl ... [Appl. Phys. Lett. 26, 46 (2008)] published Tue Sep 2, 2008.
Optical waveguide of LiNbO[sub 3] thin film grown by liquid phase epitaxy
Shintaro Miyazawa, Shoichi Fushimi, and Susumu Kondo
We report optical waveguiding of a LiNbO singlecrystal film grown onto a cplate LiTaO substrate by liquid phase epitaxy from a new LiOVO flux. A film of about 3[mu]m thickness supported seven TE and two TM modes. Measurements of the mode indices indicated that the film is a ''uniform'' waveguide hav ... [Appl. Phys. Lett. 26, 8 (2008)] published Tue Sep 2, 2008.
Electron - beam - excited DFB laser in CdS
Yoshinobu Aoyagi and Susumu Namba
Distributed feedback (DFB) laser oscillation under electronbeam excitation was observed in CdS. The linewidth of the laser spectrum was found to be less than 0.8 A. Compared to a conventional laser, the spectrum was less sensitive to temperature. The DFB lasing was observed to occur only at the star ... [Appl. Phys. Lett. 26, 24 (2008)] published Tue Sep 2, 2008.
High - sensitivity optical recording in KTN by two - photon absorption
D. von der Linde, A. M. Glass, and K. F. Rodgers
Birefringence changes are induced in a cubic potassium tantalate niobate crystal with an external electric field by twophoton absorption of picosecond optical pulses. The recording sensitivity of 100 [mu]J/cm for elementary holograms with a few percent reconstruction efficiency is comparable to the ... [Appl. Phys. Lett. 26, 22 (2008)] published Tue Sep 2, 2008.
Stimulated emission of cresyl violet pumped by N[sub 2] laser or rhodamine 6G dye laser
Francesco Castelli
Cresyl violet solutions have been shown to lase when pumped with a N laser or a rhodamine 6G dye laser. In the latter case the efficiency is much higher, and for appropriate solution concentrations the dye lases at the wavelength peak of its spontaneous emission. Under these conditions, the gain is ... [Appl. Phys. Lett. 26, 18 (2008)] published Tue Sep 2, 2008.
Pulse generation in a cw dye laser by mode - locked synchronous pumping
J. M. Harris, R. W. Chrisman, and F. E. Lytle
A continuous train of <500 ps (detector limited) pulses has been produced with a cw dye laser pumped by a modelocked argon ion laser. The cavity lengths of the dye laser and argon laser were made equal in order to synchronously amplify a single pulse oscillating in the dye laser. An intracavity acou ... [Appl. Phys. Lett. 26, 16 (2008)] published Tue Sep 2, 2008.
Influence of excited singlet absorption on output power of cw dye lasers
O. Teschke and A. Dienes
The effects of the absorption of the pump light by the first excited singlet state on the output of a Rhodamine 6G cw dye laser are investigated. Experimental results show a change in the incremental photon efficiency with pump wavelength. Theoretical expressions are derived for the output power, in ... [Appl. Phys. Lett. 26, 13 (2008)] published Tue Sep 2, 2008.
Growth strains and losses in Nb - diffused LiTaO[sub 3] optical film waveguides
V. Ramaswamy and R. D. Standley
We have observed the formation of growth strains due to interfacial dislocations in thin films made by the diffusion of niobium into LiTaO. These dislocations become significant for films wherein Deltan>~0.01; their effect is to increase the scattering loss of the optical guided waves in the film. ... [Appl. Phys. Lett. 26, 10 (2008)] published Tue Sep 2, 2008.
Etched buried heterostructure GaAs/GaAlAs injection lasers
R. D. Burnham and D. R. Scifres
An injection laser is described in which a semicircular GaAs active region is completely surrounded by GaAlAs by using selective etching and a single liquid-phase epitaxial growth.The active region dimensions can be made much more symmetric than those obtained with conventional stripe geometry laser ... [Appl. Phys. Lett. 27, 510 (2008)] published Tue Sep 2, 2008.
Relief-type diffraction grating by amorphous chalcogenide films
Yasushi Utsugi and Sakae Zembutsu
In As-Se- (S) -Ge amorphous films, a remarkable difference of chemical etching rate between the heat-treated state and the light-irradiated state has been observed. Utilizing this characteristic, a relief-type diffraction grating of the amorphous film was obtained (the pitch between grating lines, 0 ... [Appl. Phys. Lett. 27, 508 (2008)] published Tue Sep 2, 2008.
Intense laser emission at 3577 [A-ring] using N[sub 2]-SF[sub 6] mixtures in a TE nitrogen laser
Junichi Itani, Kiichiro Kagawa, and Yoshitake Kimura
Intense laser emission at 3577 A (v[prime]=0 of the Cpi state to v=1 of the Bpi state of the nitrogen molecule) has been demonstrated to take place by an addition of a large quantity of SF as a foreign gas in a transversely excited nitrogen laser. The output at 3577 A is increased with increasing pa ... [Appl. Phys. Lett. 27, 503 (2008)] published Tue Sep 2, 2008.
Optically pumped infrared V-V transfer lasers
H. Kildal and T. F. Deutsch
Laser action in OCS, CO, NO, CH, and CS has been obtained by resonant vibrational-to-vibrational (V-V) energy transfer from CO gas excited by a frequency-doubled CO TEA laser. Output energies up to 0.5 mJ, energy conversion efficiencies as high as 7%, and thresholds as low as 0.1 mJ have been observ ... [Appl. Phys. Lett. 27, 500 (2008)] published Tue Sep 2, 2008.
Electron-beam-controlled discharge pumping of the KrF laser
J. A. Mangano and J. H. Jacob
Laser action has been obtained in atmospheric-pressure mixtures of 0.1% F/2% Kr/97.9% Ar at 248.5 and 249.5 nm with electron-beam-controlled discharge pumping. The laser and discharge characteristics are explored as a function of discharge electric field and total mixture pressure. These preliminary ... [Appl. Phys. Lett. 27, 495 (2008)] published Tue Sep 2, 2008.
Pulse shortening and pulse deformation in a high-power iodine laser amplifier
N. Skribanowitz and B. Kopainsky
Pulse propagation in a photodissociative iodine laser amplifier is investigated both experimentally and numerically. Pulse reshaping and shortening occur in agreement with theory. It is found that pulse shortening by gain saturation is impractical for subnanosecond pulses. ... [Appl. Phys. Lett. 27, 490 (2008)] published Tue Sep 2, 2008.
Dynamic spectroscopy and subpicosecond pulse compression
E. P. Ippen and C. V. Shank
Picosecond pulses from a mode-locked cw dye laser have been compressed in time to produce pulses as short as a few tenths of a picosecond. Dynamic spectroscopic investigations of the laser pulses reveal temporal asymmetry and frequency chirping on a subpicosecond time scale. ... [Appl. Phys. Lett. 27, 488 (2008)] published Tue Sep 2, 2008.
External higher-index mode filters for band widening of multimode optical fibers
K. Furuya, Y. Suematsu, J. Nayyer, S. Ishikawa, and F. Tagami
External higher-index mode filters were fabricated and their filter actions were confirmed experimentally. Loading the multimode fiber with the mode filter, the increase of the pulsewidth at the half-peak value was reduced from 640 to 130 ps, at the expense of loss penalty of 0.7 dB including the co ... [Appl. Phys. Lett. 27, 456 (2008)] published Tue Sep 2, 2008.
Picosecond-gated optical amplifier
G. E. Busch, K. S. Greve, G. L. Olson, R. P. Jones, and P. M. Rentzepis
A picosecond-gated optical amplifier (PGOA) characterized by high gains (>~10), large extinction ratios (~10), and short aperture times (~10 psec) is described. The active component of the system is a saturable absorbing dye which is irradiated by a high-intensity ultrashort laser pulse. The techniq ... [Appl. Phys. Lett. 27, 450 (2008)] published Tue Sep 2, 2008.
cw double mode locking of the dye laser experiment
Z. A. Yasa and O. Teschke
A mixture of rhodamine 6G and cresyl violet is pumped by a cw argon laser. Inversion of cresyl violet by the absorption of the lasing rhodamine 6G wavelength results in doubly mode-locked operation, with an ultrashort pulse at 5740 A followed by an ultrashort pulse at 6440 A. ... [Appl. Phys. Lett. 27, 446 (2008)] published Tue Sep 2, 2008.
Lanthanum beryllate: A new rare-earth ion laser host
R. C. Morris, C. F. Cline, R. F. Begley, M. Dutoit, P. J. Harget et al.
Optical quality crystals, measuring up to 2.5 x 20 cm, of the compound LaBeO : Nd have been grown from the melt. The results of physical- and optical-property measurements and laser testing (long pulse, Q switched, and cw mode) are reported. Linearly polarized laser oscillations at 1.07 and 1.08 [mu ... [Appl. Phys. Lett. 27, 444 (2008)] published Tue Sep 2, 2008.
Spectral narrowing and electro-optical tuning of a pulsed dye laser by injection locking to a cw dye laser
J. J. Turner, E. I. Moses, and C. L. Tang
It is shown that the single-element electro-optical birefringent filter can be used to tune the relatively high-gained flashlamp-pumped pulsed dye laser across the entire dye emission band, but the resulting laser line width is relatively wide as might be expected. However, this line width could be ... [Appl. Phys. Lett. 27, 441 (2008)] published Tue Sep 2, 2008.
354-nm laser action on XeF
C. A. Brau and J. J. Ewing
This letter reports laser action on the xenon monofluoride Sigma-->Sigma band at 354 nm. Lasing on discrete vibrational bands has been achieved by pulse excitation of high-pressure mixtures of F/Xe/Ar with an electron beam. XeF is a member of a new class of diatmoic molecules, the noble gas monohali ... [Appl. Phys. Lett. 27, 435 (2008)] published Tue Sep 2, 2008.
High-power xenon fluoride laser
E. R. Ault, R. S. Bradford, Jr., and M. L. Bhaumik
High-power laser emission has been observed from xenon fluoride (XeF) at 351.1 and 353.1 nm. A peak laser power of 0.5 MW was obtained by using a mixture of Ar, Xe, and NF in the ratio of 250 : 25 : 1 at a total pressure of 1.7 atm. The laser gas was excited by a 1-MeV 20-kA electron beam for a puls ... [Appl. Phys. Lett. 27, 413 (2008)] published Tue Sep 2, 2008.
Laser emission at 1.32 mu m from atomic iodine produced by electrical dissociation of CF[sub 3]I
L. D. Pleasance and L. A. Weaver
Laser emission on the I(P) -->I(P) transition at 1.32 [mu]m has been excited for the first time in an electrical discharge. A mixture of about 1% CFI in N was excited in a uv-initiated pulsed dicharge between planar electrodes. Iodine atoms in the upper and lower laser levels are generated by dissoc ... [Appl. Phys. Lett. 27, 407 (2008)] published Tue Sep 2, 2008.
cw operation of distributed-feedback GaAs-GaAlAs diode lasers at temperatures up to 300 K
M. Nakamura, K. Aiki, J. Umeda, and A. Yariv
Distributed-feedback GaAs-GaAlAs diode lasers with separate optical and carrier confinement have been successfully operated under dc bias up to room temperature. They lased in a single longitudinal mode with a threshold current density of 0.94 kA/cm at 170 K and 3.5 kA/cm at 300 K. ... [Appl. Phys. Lett. 27, 403 (2008)] published Tue Sep 2, 2008.
Picosecond optical detection by high-speed sampling of photoelectrons
James J. Wiczer and Henry Merkelo
It is demonstrated that photoelectrons distributed in initial velocity can be extracted from electrically broad-band configurations with extremely high time resolutions. Properties and values of parameters characterizing real materials and laboratory-generated electrical sampling signals are used th ... [Appl. Phys. Lett. 27, 397 (2008)] published Tue Sep 2, 2008.
A laser velocimeter utilizing laser-induced fluorescence
Warren H. Stevenson, Reginaldo dos Santos, and Stephen C. Mettler
Addition of a fluorescent dye to the liquid used for scattering particle production in a laser Doppler velocimeter can result in a number of practical advantages. An investigation of this concept has been carried out using various dyes and solvents to determine its potential and limitations. The ter ... [Appl. Phys. Lett. 27, 395 (2008)] published Tue Sep 2, 2008.
Mixed metal vapor phase matching for third-harmonic generation
D. M. Bloom, J. F. Young, and S. E. Harris
Phase matching for frequency tripling of 1.06 [mu]m is demonstrated in a homogeneous mixture of sodium and magnesium vapor. For phase matching, the ratio of Mg to Na vapor pressures is 2 : 1. This ratio is about 1/75 of the ratio of Xe to Na required for phase matching. ... [Appl. Phys. Lett. 27, 390 (2008)] published Tue Sep 2, 2008.
Tunable distributed-feedback dye laser
Yoshinobu Aoyagi, Takashi Aoyagi, Koichi Toyoda, and Susumu Namba
A tuning range of more than 160 A was obtained in a rhodamine 6G distributed-feedback laser by using a mechanical tuning method. An electromechanical tuning of about 10 A was also obtained. ... [Appl. Phys. Lett. 27, 687 (2008)] published Tue Sep 2, 2008.
Controlled picosecond gating and amplification of ultrafast optical signals
G. L. Olson and G. E. Busch
A positively gated ultrafast amplifying shutter is described. The population inversion created by the action of an intense picosecond pulse in a saturable absorbing dye provides the means for high gain amplification of optical signals. The introduction of a second pulse at a wavelength within the em ... [Appl. Phys. Lett. 27, 684 (2008)] published Tue Sep 2, 2008.
LiNdP[sub 4]O[sub 12] laser pumped with an Al[sub x]Ga[sub 1 - x]As electroluminescent diode
Masatoshi Saruwatari, Tatsuya Kimura, Tomoaki Yamada, and Jun'ichi Nakano
Using an incoherent AlGaAs light-emitting diode (LED) as a pump source, pulsed laser oscillation was observed in a 300-[mu]m-thick LiNdPO crystal cooled to 35 degrees C. The oscillation threshold power density is 8.2 W/cm for the LED pump, and is compared with that for an Ar laser pump and theoreti ... [Appl. Phys. Lett. 27, 682 (2008)] published Tue Sep 2, 2008.
A fast scalable switching technique for high-power CO[sub 2] laser radiation
A. J. Alcock, P. B. Corkum, and D. J. James
Fast switching of high-power 10-[mu]m radiation by reflection from optically induced carriers in polycrystalline germanium has been demonstrated. Initial studies carried out with a single-mode TEA CO laser and a 2-nsec ruby laser pulse have resulted in the generation of synchronized ~2-nsec pulses o ... [Appl. Phys. Lett. 27, 680 (2008)] published Tue Sep 2, 2008.
High-pressure infrared Ar-Xe laser system: Ionizer-sustainer mode of excitation
L. A. Newman and T. A. DeTemple
Laser action on neutral Xe transitions has been achieved at 1-atm pressure in Ar-Xe and He-Xe mixtures excited in an ionizer-sustainer mode of discharge. A number of near-infrared lines oscillated in both mixtures with the strongest at 1.73 [mu]m in Ar-Xe. Over-all conversion efficiencies of 0.2% in ... [Appl. Phys. Lett. 27, 678 (2008)] published Tue Sep 2, 2008.
Polarization effects in holographic multiplexing
Hiroshi Okayama
The polarization characteristics of holograms multiplexed with the object beam of an E mode and with that of an H mode are compared. Holographic multiplexing is carried out by the technique of the Fourier transform hologram using a mask of the sector type. The characteristics obtained are evaluated ... [Appl. Phys. Lett. 27, 676 (2008)] published Tue Sep 2, 2008.
Output flux instabilities in a flowing-gas cw CO[sub 2] electric discharge laser
M. J. Yoder and D. R. Ahouse
Temporal measurements of laser output flux of a flowing-gas cw CO electron-beam-sustainer electric discharge laser exhibit large fluctuations. The amplitude of the fluctuations varies from 20 to 100% depending on cavity pressure, unstable resonator output coupling, and discharge specific power loadi ... [Appl. Phys. Lett. 27, 673 (2008)] published Tue Sep 2, 2008.
D[sub 2]-CO[sub 2] and D[sub 2]-N[sub 2]O electric discharge gas-dynamic lasers
J. A. Stregack, B. L. Wexler, and G. A. Hart
cw CO and NO lasing has been obtained in a new electric discharge gas-dynamic laser device. The device consists of a subsonic plenum discharge region where vibrational excitation occurs, a supersonic nozzle array where the laser species is injected, and a supersonic cavity where mixing, energy trans ... [Appl. Phys. Lett. 27, 670 (2008)] published Tue Sep 2, 2008.
Pump absorption and saturation in the CH[sub 3]F 496-mu m laser
D. T. Hodges and J. R. Tucker
Results are presented from a series of diagnostic experiments designed to measure the fundamental absorption parameters in CHF for the P (20) CO laser line at 9.55 [mu]m. These parameters include the small-signal absorption coefficient, the saturation intensity for the absorbing transition, and the ... [Appl. Phys. Lett. 27, 667 (2008)] published Tue Sep 2, 2008.
Stimulated Raman scattering at kHz pulse repetition rates
E. O. Ammann and Joel Falk
Stimulated Raman scattering (SRS) has been achieved at kHz pulse repetition rates. The Raman oscillator consists of a lithium iodate crystal placed inside a Nd:YAlO laser, with feedback provided at the Stokes wavelengths by mirrors surrounding the crystal. First and second Stokes outputs at 1.18 and ... [Appl. Phys. Lett. 27, 662 (2008)] published Tue Sep 2, 2008.
Mode locking of a He-Ne 3.39-mu m laser using strong internal phase modulation
Satoshi Konishi, Tetsuro Kobayashi, and Tadasi Sueta
The possibility of generating ultrashort optical pulses from narrow-linewidth lasers by means of mode locking is discussed. An experiment using a He-Ne 3.39-[mu]m laser and applying strong intracavity phase (FM) modulation of 580 MHz was performed to demonstrate the possibility. The oscillation band ... [Appl. Phys. Lett. 27, 660 (2008)] published Tue Sep 2, 2008.
Improved cw laser action on the 118.6- and 220-mu m H[sub 2]0 transitions using helium and hydrogen
P. Woskoboinikow and W. C. Jennings
The power of a cw water-vapor laser operating on the far-infrared transitions of 118.6 and 220 [mu]m has been considerably improved by the use of helium and hydrogen gas additives. The laser power on the 118.6-[mu]m transition has been increased by an order of magnitude from 1.5 to 15 mW in a nonopt ... [Appl. Phys. Lett. 27, 658 (2008)] published Tue Sep 2, 2008.
Vibration-vibration pumping of carbon monoxide initiated by an optical source
J. W. Rich, R. C. Bergman, and J. W. Raymonda
A steady-state nonequilibrium population distribution of the vibrational states of carbon monoxide has been produced by optical pumping. A supersonic flow CO laser was used to excite a flowing mixture of CO which is pressure broadened by argon. A V-V pumped nonequilibrium distribution was measured o ... [Appl. Phys. Lett. 27, 656 (2008)] published Tue Sep 2, 2008.
Vibration-vibration pumping of carbon monoxide initiated by an optical source
J. W. Rich, R. C. Bergman, and J. W. Raymonda
A steady-state nonequilibrium population distribution of the vibrational states of carbon monoxide has been produced by optical pumping. A supersonic flow CO laser was used to excite a flowing mixture of CO which is pressure broadened by argon. A V-V pumped nonequilibrium distribution was measured o ... [Appl. Phys. Lett. 27, 656 (2008)] published Tue Sep 2, 2008.