Dispersive Fourier transformation femtosecond stimulated Raman scattering

Dobner S, Fallnich C.

Abstract

In summary, we have demonstrated the applicability of a purely passive dispersive Fourier transformation (DFT) to femtosecond stimulated Raman scattering (FSRS) spectroscopy. Using FSRS, it was possible to excite the stimulated Raman signal, i.e., the Raman scattering spectrum, over a spectral range spanning from 700 to 3700 cm-1. The detection of the Raman signatures was performed with purely passive DFT, i.e., without any need for an optical amplification. The acquisition time for one Raman scattering spectrum amounted to 2 μs. A 20-time-averaged DFT-FSRS spectrum resulted in a S/N ratio comparable to a standard CCD-spectrometer-based FSRS reading. As the presented DFT-FSRS scheme is still scalable to even lower pixel dwell times, it shows a promising potential to be applied in high-speed hyperspectral imaging.