Coherent multistep anti-Stokes and stimulated Raman scattering associated with third harmonics inYFeO3crystals

Multicolored light pulses are generated with high efficiency in the visible region by injecting two ultrashort light pulses with infrared frequencies into orthoferrite ${\mathrm{YFeO}}_3$ single crystals. The spectrum of the multicolored light pulses consists of third harmonics of two beams and higher-order coherent anti-Stokes Raman scattering. This is generated by the excitation of a phonon in the crystal resonating to the frequency difference of two incident beams. The spectrum of the emitted light signals covers a frequency region wider than $5000{\mathrm{cm}}^{-1}$ with the same frequency separation equal to that of the coherently driven phonons.