Abstract
Planar and channel optical waveguides were fabricated in Cu doped KTiOPO4 (KTP) substrates using Rb+:K+ ion exchange process and annealing process. The effective refractive indices were measured using the m-line method and the refractive index profiles of these waveguides were calculated using the inverse WKB method. For waveguides in Cu:KTP substrates the difference of diffusion depth d and index change Delta n at the z(-) and z(+) surfaces can hardly be observed. This observation is different from KTP. Compared with undoped KTP substrates the diffusion depth d at the z(-) surfaces is larger, whereas the index change Delta n is smaller. At the z(+) surfaces both d and Delta n are larger. The light induced effective index changes in Cu doped KTP channel waveguides were measured at 0.476, 0.488, 0.514, 0.6328, and 0.83 mu m wavelengths. No changes were observed at the power flow of 1x10(8) W/m(2), revealing that Cu ion does not play an important role in photorefractive effect of KTP crystals. (C) 1997 American Institute of Physics. [S0003-6951(97)02945-8].