Abstract

Cascading phenomena are related to the back action effect of the second harmonic (SH) on the phase of the primary radiation. This has recently attracted much interest in the field of ultrafast all-optical switching applications, where the amplitude of the second order nonlinear coefficient χ⁽²⁾ has to be accurately known. However, obtaining a precise measurement of χ⁽²⁾ usually requires a calibration against a perfectly known nonlinear reference crystal. Moreover, the influence of cascading on the spectrum of the harmonic pulse, which has hardly been seen using pisosecond pulses, has never been explored in the femtosecond regime.

© 1998 IEEE