The application of nonlinear Raman spectroscopy to provide molecular specificity in 3-D biological imaging

Summary form only given. Coherent Anti-Stokes Raman Spectroscopy (CARS) has been applied to microscopic imaging and is similar in method and application to two-photon fluorescence microscopy. A Stokes-shifted laser source (an optical parametric amplifier operating at 250 kHz), in combination with the 200 fs pump laser, is tightly focused into the sample, with high peak power but with nanojoule pulse energy. The stimulated signal is orders of magnitude stronger than conventional Raman signals and in addition has a very high contrast due to insignificant autofluorescence.