Asst. Prof. Kazuki Hashimoto, University of Tokyo, Japan

Leuchs-Russell Auditorium, A.1.500, Staudtstr. 2

Location Details

Abstract
Mid-infrared (MIR) spectroscopic techniques, typified by Fourier-transform infrared (FTIR) spectroscopy, have long been used across various fields to identify substances through molecular vibrations. However, conventional FTIR systems normally offer measurement rates of only a few Hz, limiting their applicability primarily to static samples. Accelerating MIR spectroscopy is essential for tracking fast dynamical processes and enabling high-throughput hyperspectral imaging, where massive numbers of spectra must be acquired rapidly. Although recent advances in MIR spectrometers, such as MIR dual-comb spectroscopy and frequency-swept techniques, have improved acquisition rates, they have generally remained at the MHz level.
In this work, we demonstrate the feasibility of acquiring MIR spectra at 10s MHz rates by introducing time-stretch detection into MIR spectroscopy. Time-stretch spectrometry requires imparting substantial group-velocity dispersion (typically via optical fibers) to temporally stretch ultrashort pulses. We realize this approach in the MIR by leveraging wavelength-conversion techniques to circumvent the limited availability of dispersive MIR components. In this talk, I present two MIR time-stretch spectroscopic schemes that we have recently demonstrated and introduce several related time-stretch-based spectroscopic techniques developed in our laboratory.