D. Kip et al., CONCENTRATION AND REFRACTIVE-INDEX PROFILES OF TITANIUM-DIFFUSED AND IRON-DIFFUSED PLANAR LINBO3 WAVE-GUIDES, Physica status solidi. a, Applied research, 139(1), 1993, pp. 241-248
Depth profiles of titanium, iron, and niobium concentrations are inves
tigated with an electron microprobe in planar optical LiNbO3:Ti wavegu
ides additionally doped with iron. The profiles are well described by
Gaussian functions allowing the determination of diffusion constants.
The extraordinary refractive index of the waveguides can be described
by a linear superposition of iron and titanium profiles.