Abstract

The combination of two novel techniques second order cascading [1] and quasi phase matching [2] (QPM) can yield to solutions for construction small, low power operated, all-optical switching devices. Important parameters in this devices are the switching intensities I_π/2 and I_π necessary for obtaining nonlinear phase shift (NPS) with amount of π or π/2, correspondingly. Here we show that one way to reduce the parameters I_π/2and I_π is to use aperiodic quasi-phase matched structure. We investigated the NPS obtained by the fundamental beam involved in the process of second harmonic generation in second order material for which the normalized phase mismatch satisfy where k_i=2πn_i/λ_i (i=ω,2ω), p is a coefficient and K_grat(z) = 2π/Λ_grat(z) with Λ_grat being the grating period.

© 1998 IEEE