Linear time reversal of infrared light mitigates phase distortions of signals on a silicon chip
Linear time reversal of infrared light mitigates phase distortions of signals on a silicon chip lead image
The accurate manipulation of photons lies at the core of advancements in optoelectronics and photon-based quantum computing. In order to enhance performance, the authors examined how to reduce phase distortions that light experiences as it moves through optical media and between system components.
New experimental evidence points to a path toward enhanced signal quality involving the use of a concept known as the time reversal of light, and, for the first time, Konoike et al. have demonstrated the dynamic, all-linear time reversal of infrared light in planar optical circuits.
By dynamically tuning coupled photonic crystal nanocavities on a silicon chip via virtual excitation of intermediate line-defect waveguides, the group was able to time reverse the oscillatory motion of light on a chip. Reversing the dispersion of light in this way allows researchers to compensate for phase distortions.
Time-reversal operations can change the state of the light waves as if they are flowing backward in time, eventually returning to the original state as they left their source.
Up until now, all other successful attempts at time-reversing light have employed nonlinear optical systems, an approach that requires light at high intensities, which cannot be easily achieved on a chip.
“We believe that our results will lead to future large-scale photon manipulation platforms on a chip that allows for the on demand control of light,” said author Ryotaro Konoike.
The authors said it is possible to time-reverse any input light provided that their proposed system is connected in series.
Konoike said the group looks to test their system by placing several cavities together on a chip. They hope to develop more ways to manipulate the nanocavities.
Source: “On-chip dynamic time reversal of light in a coupled-cavity system,” by R. Konoike, T. Asano, and S. Noda, APL Photonics (2019). The article can be accessed at https://doi.org/10.1063/1.5080359 .
