Abstract

During the last few years, several methods have been developed for the modulation of the second-order nonlinear susceptibility in nonlinear materials. These methods were mostly applied to create periodic structures, in order to obtain quasi-phase-matching for a singlenonlinear interaction. However, a periodic structure generally fails to solve the problem for the case of multiple arbitrary interactions One example of a device, which requires phase-matching for several interactions simultaneously, is a frequency tripler (ω→3ω), where phase-matching is required both for the second-harmonic generation process (ω→2ω) as well as for the sum frequency generation process of the fundamental frequency and the second-harmonic (ω+2ω→3ω). Other interesting examples include frequency quadruplets and multiple-peak frequency doublers.

© 2000 IEEE