Yoshiatsu Yokoo

Photorefractive damage removal in annealed-proton-exchanged LiNbO3 channel waveguides

Ion beam implantation has been used as a postprocessing technique to dramatically reduce the photorefractive effect in lithium niobate channel waveguides. The waveguides were fabricated by proton exchange and then annealed 1.0 MeV H+ ions were implanted through the existing channel waveguides such that the “damaged layer” was created beneath the existing channel waveguide. The output characteristics from the waveguides were subsequently examined. Highly stable single-mode outputs were observed with the waveguides retaining up to 95% of their original transmission. It is thought that this decrease in photorefractive susceptibility can be explained by the implant changing the defect structure and hence photovoltaic properties of the material.