Center for Relativistic Laser Science

125th KCS 

Abstract

Stimulated Raman scattering (SRS) microscopy has been regarded as a useful technique to investigate chemical components by selectively targeting vibrational modes of chemical structures. In applications of observing molecular environments and dynamics in complex biological environments, both high signal-to-noise ratio and spectral resolution within wide spectral range are required. Here, we show a two-color SRS microscope using a balance detection method and a spectral focusing method. Two different SRS signals are generated by a pair of vertically polarized pump and Stokes laser pulses, each of which acts as an intensity reference to each other, significantly reducing background noise levels close to the shot noise limit even in fiber-based femtosecond Laser system. High spectral resolution comparable to spontaneous Raman scattering spectroscopy is achieved with a spectral focusing method. Two-color SRS images are obtained for the mixture of polymer beads and the distribution of lipids and proteins in U2OS cells.