Molecular vibration imaging in the fingerprint region by use of coherent anti-Stokes Raman scattering microscopy with a collinear configuration

Abstract

We have developed a new coherent anti-Stokes Raman scattering (CARS) microscopy system with a collinear configuration for use in the fingerprint region. The system consists of a picosecond laser system and a transmission-type laser scanning microscope without a pinhole in front of the detector. The observable Raman-shift region is $900–1750 {\mathrm{cm}}^{-1}$, the spectral resolution is $30 {\mathrm{cm}}^{-1}$, and the spatial resolution is smaller than $1 \mathit{\mu }\mathrm{m}$ in the lateral direction and $3.2 \mathit{\mu }\mathrm{m}$ in the depth direction, with objectives with a numerical aperture of 0.65. CARS spectra and images of polystyrene beads are demonstrated, and CARS imaging of a viable yeast cell is attempted.