Goda Lab

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.

• P. C. McCann, K. Hiramatsu, and K. Goda, "Highly sensitive low-frequency time-domain Raman spectroscopy via fluorescence-encoding", Journal of Physical Chemistry Letters 12, 7859 (2021)
• J. Gala de Pablo, M. Lindley, K. Hiramatsu, and K. Goda, "High-throughput Raman flow cytometry and beyond", Accounts of Chemical Research 54, 2132 (2021)
• N. Nitta, T. Iino, A. Isozaki, M. Yamagishi, Y. Kitahama, S. Sakuma, Y. Suzuki, H. Tezuka, M. Oikawa, F. Arai, T. Asai, D. Deng, H. Fukuzawa, M. Hase, T. Hasunuma, T. Hayakawa, .., D. Di Carlo, Y. Hosokawa, S. Uemura, T. Sugimura, Y. Ozeki, and K. Goda, "Raman image-activated cell sorting", Nature Communications 11, 3452 (2020)
• K. Hiramatsu, T. Tajima, and K. Goda, "Ultrafast, dual-band coherent Raman spectroscopy without ultrashort pulses", ACS Photonics 9, 3522 (2022)
• 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)
• M. Lindley, K. Hiramatsu, H. Nomoto, F. Shibata, T. Takeshita, S. Kawano, and K. Goda, "Ultrafast simultaneous Raman-fluorescence spectroscopy", Analytical Chemistry 91, 15563 (2019)