Light sheet Raman micro-spectroscopy

Abstract

Raman spectroscopy is a laser spectroscopic method that reveals detailed chemical information about a sample. Point-wise scanning produces chemical maps of heterogeneous samples such as biological tissue without prior staining. However, the intrinsically low Raman scattering cross-sections result in long acquisition times, despite the high excitation intensity in the focus. Here, we present a novel technique termed light sheet Raman micro-spectroscopy, which is an imaging spectrometer attached to a light sheet illumination microscope that can quickly acquire large hyperspectral Raman images. This method is more than 5 times faster than conventional approaches, while reducing the local excitation intensity over 300 fold. We show a stack of hyperspectral Raman images of a zebrafish eye with 1024×1024×50 spectra (17 min/slice) to demonstrate how the application of spontaneous Raman micro-spectroscopy can be extended to biomedical research and diagnosis based on directly utilizing the molecular information present in the sample.