Background-free 3D chemical imaging based on polarization coherent Raman holography.

We report on a holographic coherent anti-Stokes Raman scattering imaging by using polarization discrimination for nonresonant background suppression. With reduced polarization scrambling effect under weakly focused excitation, nonresonant background-free coherent Raman imaging is demonstrated. A fast chemically selective imaging is achieved in a three-dimensional volume of 70 µm ×70 µm ×100 µm in 2 s.