2ND-HARMONIC GENERATION AND CASCADED 2ND-ORDER PROCESSES IN A COUNTERPROPAGATING QUASI-PHASE-MATCHED DEVICE

Numerical solutions to the nonlinear coupled-wave equations of a count erpropagating quasi-phase-matched device are analyzed by numerical met hods for both second-harmonic generation and cascaded processes. Norma lized derivations for second-harmonic generation efficiency are also p resented. The nonlinear phase shifts acquired in this device by cascad ed second-order processes are promising in ah-optical-switching applic ations. Specifically, a pi/2 phase shift is shown to be achievable wit h 42 times less input intensity than the standard Type I configuration and 100% throughput. The effects of metallic mirrors are also present ed. Careful use of the phase mismatch is shown to compensate for nonid eal mirrors. Finally, conservation of power in this configurations bri efly investigated. (C) 1998 Optical Society of America. OCIS codes: 19 0.4360, 230.4320.