Time and Temperature Dependent Study of Zn and Ni Codiffused LiNbO 3 Waveguides

Zn and Ni codiffused lithium niobate planar and channel waveguides are fabricated at various temperatures for different times. Compositional and optical properties of the waveguides are studied. Single-mode channel waveguides are measured for 2-D refractive index profiling using a modified end-fire coupling method at excitation wavelengths of both 633 and 1550 nm. Planar waveguides with the same metallic thicknesses as those of channel waveguides are analyzed using secondary-ion-mass-spectrometry to obtain the diffused metal ion concentration profiles. The relationship between the diffusion depths and index depths is discussed based on the completeness of the diffusion process.