Vibrational Stark Spectroscopy on Fluorobenzene with Quantum Cascade Laser Dual Frequency Combs

Abstract

We demonstrate the performance of a dual frequency comb QCL spectrometer for the application of vibrational Stark spectroscopy. Measurements performed on fluorobenzene with the dual-comb spectrometer (DCS) were compared to results obtained using a conventional Fourier transform infrared (FTIR) instrument in terms of spectral response, parameter estimation, and signal-to-noise ratio. The dual-comb spectrometer provided similar qualitative and quantitative data as the FTIR setup in 250 times shorter acquisition time. For fluorobenzene, the DCS measurement resulted in a more precise estimation of the fluorobenzene Stark tuning rate ((0.81 +/- 0.09) cm-1/(MV/cm)) than with the FTIR system ((0.89 +/- 0.15) cm-1/(MV/cm)). Both values are in accordance with the previously reported value of 0.84 cm-1/(MV/cm). We also point to an improvement of signal to noise ratio (SNR) in the DCS configuration. Additional characteristics of the dual-comb spectrometer applicable to vibrational Stark spectroscopy and their scaling properties for future applications are discussed.