POLING AND CHARACTERIZATION OF POLYMER WAVE-GUIDES FOR MODAL DISPERSION PHASE-MATCHED 2ND-HARMONIC GENERATION

New multilayer polymer waveguides have been introduced with inverted n onlinear layers for efficient modal dispersion phase-matched second-ha rmonic generation at the telecommunication wavelength near 1.55 mu m. The nonlinear optical core of the waveguides consists of two modified Disperse Red 1-based side-chain polymers with different glass-transiti on temperatures. The signs of the nonlinear optical coefficients are d ifferent in the two polymers after suitable poling above and between t he respective glass transitions, thereby optimizing the overlap integr al. The optical nonlinearity profile is controlled by in situ electro- optical measurements during the two poling steps. The successful prepa ration of inverted layers is verified by electro-optical, pyro-electri cal, and second-harmonic-generation thermal analysis. Waveguide losses are low at 1.55 mu m (4 dB/cm) and high at 800 nm (100 dB/cm) because of the residual absorption of the Disperse Red 1-like chromophores. P hase-matched second-harmonic generation has been demonstrated with a l arge figure of merit, 14%/W cm(-2). Extensive room for improvement in second-harmonic generation is possible with optimized chromophores, be cause the total conversion efficiency is strongly limited by the harmo nic losses in the modified Disperse Red 1. (C) 1998 Optical Society of America.