Light-induced refractive index changes in singlemode channel waveguides in KTiOPO4

Abstract Light-induced changes of the effective refractive index in Rb ↔ K ion-exchanged singlemode channel waveguides in KTiOPO 4 have been investigated in the visible wavelength region dependent on time, guided optical mode intensity and temperature. A hypothesis for the explanation of the light-induced effects is suggested. Thermooptic and pyroelectric effects are discussed. The light-induced refractive index changes do not restrict the function of integrated-optic components in the visible.