Fourier-transform coherent anti-Stokes Raman scattering (FT-CARS) spectroscopy is a time-domain Raman spectroscopic method, where molecular vibrations are excited and interrogated with ultrashort pulses. FT-CARS spectroscopy is distinguished from other coherent Raman methods, such as frequency-domain CARS and stimulated Raman scattering spectroscopy, by its capability to produce broadband, background-free Raman spectra. The spectral acquisition rate of FT-CARS, which is determined by the scanning rate of the delay between ultrashort pump-probe pulses, can be higher than a few tens of kHz using a rapid mechanical scanner or dual-comb techniques. FT-CARS spectral bandwidth is determined by its optical pulse bandwidth, resulting in Raman spectra spanning more than 3,000 cm−1 demonstrated with sub-10 fs pulses.
Initially developed with an eye toward microscopy, the progression of FT-CARS spectroscopy to the ultrafast regime has opened the technique to high-throughput applications such as Raman flow cytometry and high-speed chemical imaging. Currently, we aim to maximize the capability of FT-CARS spectroscopy in its speed, bandwidth, and sensitivity based on the state-of-the-art optical techniques and pioneer a new class of chemical, biological, medical, and environmental applications.
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- K. Hiramatsu, T. Ideguchi, Y. Yonamine, S. Lee, Y. Luo, K. Hashimoto, T. Ito, M. Hase, J. Park, Y. Kasai, S. Sakuma, T. Hayakawa, F. Arai, Y. Hoshino, and K. Goda, "High-throughput label-free molecular fingerprinting flow cytometry", Science Advances 5, eaau0241 (2019)
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Coherent Raman Spectroscopy
- Field leader: Kotaro Hiramatsu
- Funding: JSPS Core-to-Core Program, KISTEC, Nakatani Foundation
- Collaboration: Serendipity Lab