PHASE-MATCHED SECOND-HARMONIC GENERATION IN PLANAR WAVE-GUIDES

Second-harmonic generation exploiting evanescent field interaction has been investigated for a planar dielectric waveguide covered with a th in organic layer. The coherent nature of the frequency-doubling proces s in such a structure was studied experimentally by systematic ablatio n of the nonlinear film in an in situ setup. An increase in the conver sion efficiency by two orders of magnitude has been observed for a non optimized second-order susceptibility of the coverage layer.Second-har monic generation exploiting evanescent field interaction has been inve stigated for a planar dielectric waveguide covered with a thin organic layer. The coherent nature of the frequency-doubling process in such a structure was studied experimentally by systematic ablation of the n onlinear film in an in situ setup. An increase in the conversion effic iency by two orders of magnitude has been observed for a nonoptimized second-order susceptibility of the coverage layer.