Abstract

Cascading of χ⁽²⁾ nonlinearities, due to the large phase shifts obtainable at the fundamental frequency through up- and down-conversion in phase-mismatched second harmonic generation, is a novel and promising approach to all-optical switching. [1] Since nonlinear phase shifts drive most all-optical devices, some typical guided-wave configurations have been in vestigated in the presence of a cascaded second-order interaction. [2,3] In this communication we analyze numerically the operation of a distributed feedback grating (DFBG) realized in a χ⁽²⁾ material, focussing on the simple case of a periodic corrugation coupling forward and backward waves at the fundamental frequency (FF, ω). As shown below, due to the nonlin-early generated phase-shift in the FF waves, an initially reflecting structure is able to switch to a transmitting state when the input power is increased.

© 1995 Optical Society of America