Ultra-broadband rapid-scan Fourier-transform CARS spectroscopy with sub-10-fs optical pulses.

We demonstrate ultra-broadband Fourier-transform coherent anti-Stokes Raman scattering (FT-CARS) spectroscopy spanning over 3,000 cm-1 with a rapid-scan Michelson interferometer at a scan rate of 24,000 spectra/s. Using sub-10-fs optical pulses from a mode-locked laser, we measure broad CARS spectrum covering both the fingerprint region (500-1,800 cm-1) and the C-H, N-H, O-H stretching region (2,700-3,600 cm-1). To the best of our knowledge, this is the first demonstration of coherent Raman scattering spectroscopy covering over 3,000 cm-1 at a scan rate of more than 10,000 spectra/s. Our system holds the potential for high-speed or high-throughput label-free chemical analysis, such as investigating non-repetitive chemical dynamics, taking large area images of materials or biological specimens, or counting and sorting a large number of heterogeneous cells.