Waveguides Fabricated in LiNbO₃ by Proton Implantation

Abstract

Optical planar waveguides, with a controllable thickness in a very wide range, typically from 3 to 20 μm, can be fabricated by thermally controlled proton implantation in LiNbO3. In the nuclear stopping region at the end of the ion's tracks a sufficient decrease in refractive index is obtained, thus forming an adequate optical barrier. The mode confinement was investigated by dark line mode spectroscopy, and the refractive index profiles were reconstructed. The effects of different ion fluences and ion energies in the Mev range on the refractive index profile at 300 K have been investigated.