Abstract
Ti-indiffused LiNbO3 waveguides offer a variety of applications since they can support both TE and TM
modes. In this work we optimized the conditions to establish the fabrication techniques of Ti-indiffused
waveguides for telecommunication wavelength in photorefractive damage resistant MgO (5 mol%):
LiNbO3. We found that Ti-indiffusion with a slow temperature rise in dry Ar was effective for obtaining
a smooth waveguide surface. The effects of Ti film thickness and diffusion conditions on the
waveguiding properties were examined. We obtained waveguide of good quality with propagation
losses of 3.5 dB/cm (TM) and 1.6 dB/cm (TE) at 1.55-μm wavelengths and 4.7 dB/cm (TM) and 4.9 dB/
cm (TE) at 0.79-μm wavelengths by the diffusion of Ti stripe (250 nm thickness, 8.0 μm width) on the
-Z surface at 1135 ℃ for 12 h in wet O2 after heating up at 15 ℃/min (20~750 ℃), 3 ℃/min
(750~1135 ℃) in dry Ar.
