CARS spectroscopy from a single fiber laser oscillator

In this work we demonstrate a new concept for CARS spectroscopy, in which multiple continuously tunable narrowband phase-coherent pulses are obtained by spectral compression of femtosecond pulses emitted by a single fiber laser. Spectral compression is achieved through second harmonic (SH) generation processes in periodically-poled crystals (PPLN) according to a method recently developed by the proponents. Besides compactness and simplicity, a key advantage of our approach is the possibility of easily synthesizing a third phase-coherent color, with straightforward implementation of FM-CARS or I-CARS techniques.