Evidence for Third-Harmonic Generation in Disguise of Second-Harmonic Generation in Extreme Nonlinear Optics

T. Tritschler, O. D. Mücke, M. Wegener, U. Morgner, F. X. Kärtner
2003 Physical Review Letters  
In contrast with traditional nonlinear optics, a peak at the spectral position of the second harmonic of a laser can also be generated in an inversion-symmetric medium in the regime of extreme nonlinear optics. We describe the underlying mechanism of such third-harmonic generation in disguise of secondharmonic generation and compare theory with the optical as well as the radio-frequency spectra measured in recent experiments on thin ZnO films. The peak at twice the carrier-envelope offset
more » ... ncy in the radio-frequency spectra is shown to be an unambiguous signature of such a process.
doi:10.1103/physrevlett.90.217404 pmid:12786589 fatcat:vgyovuxfvjh4rf4bq2vhmbwqea