Titanium free optical waveguides in lithium niobate produced by Etching During Indiffusion of titanium (EDIT)

Numerous techniques to fabricate optical waveguides in LiNbO₃ have been reported, which include Li₂O out diffusion, metal in-diffusion, ion exchange, proton exchange, strain induced waveguides, ion implantation/irradiation, using the photo-refractive effect and ultrafast or UV laser writing. We have recently reported a technique to surface machine LiNbO₃ etching during the indiffusion of Ti (EDIT), where one X cut sample is prepared with a patterned film of titanium. This is then placed in contact with another unprocessed X-cut sample and the pair is annealed in a wet oxygen atmosphere. After annealing, the originally unpatterned wafer is etched corresponding to the Ti patterns on the other wafer. In this work, we report on the observation of waveguiding in LiNbO₃ that has been EDIT patterned.