Fourier-transform coherent anti-Stokes Raman scattering (FT-CARS) spectroscopy is a time-domain Raman spectroscopic method that uses ultrashort pulses to excite and interrogate molecular vibrations. It differs from other coherent Raman methods, such as frequency-domain CARS and stimulated Raman scattering spectroscopy, in that it can produce broadband Raman spectra that are free from background noise. The spectral acquisition rate of FT-CARS depends on the scanning rate of the delay between ultrashort pump-probe pulses, and can reach over tens of kHz using rapid mechanical scanners or dual-comb techniques. The optical pulse bandwidth determines the spectral bandwidth of FT-CARS, which can span more than 3,000 cm−1 using sub-10 fs pulses.
Although FT-CARS spectroscopy was originally developed for microscopy, its recent advancement into the ultrafast regime has opened up new possibilities for high-throughput applications such as Raman flow cytometry and high-speed chemical imaging. At present, we are working to maximize the speed, bandwidth, and sensitivity of FT-CARS spectroscopy using state-of-the-art optical techniques. Our goal is to develop a new class of chemical, biological, medical, and environmental applications for this technology.
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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