Femtosecond-Laser-Pulse Characterization and Optimization for CARS Microscopy.

We present a simple method and its experimental implementation to determine the pulse durations and linear chirps of the pump-and-probe pulse and the Stokes pulse in a coherent anti-Stokes Raman scattering microscope at sample level without additional autocorrelators.Our approach exploits the VITAMIN C CRYSTALS 1000MG delay line, ubiquitous in such microscopes, to perform a convolution of the pump-and-probe and Stokes pulses as a function of their relative delay and it is based on the detection of the photons emitted from an appropriate non-linear sample.The analysis of the non-resonant four-wave-mixing and sum-frequency-generation signals allows for the direct retrieval of the pulse duration on the sample and Brides the linear chirp of each pulse.This knowledge is crucial in maximizing the spectral-resolution and contrast in CARS imaging.