Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature

We demonstrate Fourier synthesis of multiple coherent anti-Stokes Raman scattering signals in a LiNbO3 crystal at room temperature. The signals up to the 20th order (470–800nm) were generated by two crossing femtosecond Ti:sapphire laser pulses. Angle dispersion of the signals was compensated into one white-continuum beam by modifying a conventional 4f configuration. Spectral phase of the signal was measured by spectral phase interferometry for direct electric-field reconstruction. Isolated pulses with 25fs duration at 1kHz were generated only by appropriately aligning the angle-dispersion compensator. This result opens the possibility of the generation of subfemtosecond pulses in the visible region.