Probing intramolecular bonds just became much faster
Probing intramolecular bonds just became much faster lead image
When 1D spectra contain too much data to easily digest, 2D spectroscopy can disentangle important information. In low frequency regions of the electromagnetic spectrum, the technique explores the very basic bonds between molecules, allowing for the characterization of biologically relevant liquids like water.
However, those experiments can take 7-10 days, which creates difficulties in keeping the laser and environment consistent. Duchi et al. designed a 2D-Raman-THz setup that implements multichannel detection to reduce experiment times from a week to a few hours.
The setup utilizes echelons to generate separate terahertz fields from the laser and image the transmission through the sample many times at once.
“Before, we had one single terahertz wavefront going through the sample. That was one piece of information,” said author Marta Duchi. “Now, instead of having one piece of information, in one laser shot, we can detect 32 pieces of information at once.”
The researchers improved their signal-to-noise by increasing the repetition rate of the laser and amplifying the signal transmission after it passes through the sample and detection crystal. They performed 2D-Raman-THz spectroscopy of liquid bromoform to compare their setup to past results and quantify the speed up time.
While this setup greatly reduces acquisition times, Duchi said there is still room for improvement. Looking ahead, the team aims to characterize ionic liquids and hopes their work will make 2D-Raman-THz spectroscopy more widely applicable.
Source: “2D-Raman-THz spectroscopy with single-shot THz detection,” by Marta Duchi, Saurabh Shukla, Andrey Shalit, and Peter Hamm, Journal of Chemical Physics (2021). The article can be accessed at https://doi.org/10.1063/5.0065804 .
This paper is part of the Time-resolved Vibrational Spectroscopy Collection, learn more here .
