Efficient second-harmonic generation and modal dispersion effects in orientation-patterned GaAs waveguides.

Efficient second-harmonic conversion of 4 microm radiation was demonstrated in orientation-patterned GaAs (OPGaAs) waveguides (WGs). An experimentally corrected phase-matching curve for second harmonic generation (SHG) in OPGaAs WGs is presented. Influence of WG modes on the SHG process was studied. Two distinct types of SHG in the waveguides were identified and related to the TE and TM modes. Each type has its own dependence on pump polarization. The 21% W(-1) normalized conversion efficiency is within a factor of 0.75 from the predicted value for an ideal WG.