Abstract

We describe a technique that permits molecular specificity in microscopy while retaining good spatial resolution. Specificity is achieved by using Raman scattering from characteristic molecular vibrations, and high resolution is obtained by imaging the distribution of visible anti-Stokes radiation. Images have been obtained from a variety of pure organic liquids, from deuterated water in onionskin cells, deuterated liposomes, and other samples. Thermal and dielectric breakdown damage to even fragile biological materials is made negligible by choice of duty cycle and average power. Sample fluorescence is avoided by choice of anti-Stokes imaging. Imaging through (usually astigmatic) spectrometers is not needed. Deuterium substitution can be used as a general purpose and artifact-free stain. The combination of high spatial resolution, excellent molecular discrimination, and digital image processing (background subtraction, etc.) provice the CARS microscope with capabilities not found in any other current microscopic imaging technique.

© 1986 Optical Society of America