Third-harmonic generation with no signal at 3ω -: art. no. 043812

Phase matching of a spectrally broadened pump pulse and its group-velocity-mismatched third harmonic gives rise to a frequency-shifted peak, dominating the spectrum of the third harmonic, with no signal produced at the frequency 3 omega(0),omega(0) being the carrier frequency of the pump field. The central frequency of this peak, controlled by the phase and group-velocity mismatch of the pump and third-harmonic pulses, as well as the spectral broadening of the pump field, may considerably deviate from the frequency 3 omega(0), dictated by the standard energy-conservation relation for third-harmonic generation. This non-3 omega third-harmonic generation is shown to result in interesting and practically significant spectral-transformation phenomena in photonic-crystal fibers.