Multi-plate continuum laser for pre-resonance coherent Raman scattering
Journal
Biomedical Imaging and Sensing Conference
Start Page
62
Date Issued
2023-09-20
Author(s)
Editor(s)
Abstract
Raman scattering is known to offer a label-free imaging contrast with chemical bond specificity. However, the scattering cross section of Raman interaction is extremely weak. In order to boost Raman signal strength for high-speed imaging, coherent Raman interaction and electronic pre-resonance enhancement are two potential strategies. For coherent Raman scattering, two lasers with one fixed frequency and one tunable frequency, serving as pump and Stokes beams, are necessary to match the vibrational frequencies of specific molecules or chemical bonds. On the other hand, to achieve electronic pre-resonance, it is required to tune both pump and Stokes laser frequencies simultaneously. In this work, we develop a multi-plate continuum (MPC) source that delivers octave-spanning bandwidth (600-1300 nm) and high spectral energy density (~1 nJ/cm-1). This source not only enables coherent Raman enhancement with spectroscopic interrogation across the entire Raman active region (0-4000 cm-1), but also provides additional two orders of magnitude enhanced signal strength through electronic pre-resonance. The imaging modalities of stimulated Raman scattering (SRS) and coherent anti-Stokes Raman scattering (CARS) are both demonstrated with the MPC light source, on a fixed Drosophila brain tissue. We envision that utilizing MPC light source will substantially enhance the sensitivity and specificity of SRS by implementing electronic pre-resonance and spectral multiplexing via accessing three or more coherent wavelengths.
Subjects
brain neuroscience
chemical imaging
laser scanning microscopy
super-continuum
tunable laser
SDGs
Publisher
SPIE
Type
journal article