Monomode channel waveguide in KTiOPO₄ crystal produced by Rb+ ion exchange combined with Si+ ion implantation

摘要

A novel ion exchanged channel KTiOPO₄ waveguide formation technique is introduced, which can avoid a metal mask being dissolved in an ion exchanged molten salt. Rb+ ion exchange (340°C, 30 min) was first applied to a KTP sample to produce a planar waveguide substrate, and then Si+ ion implantation (3.0 MeV and 1.5 MeV with doses of 1×1015 ions/cm2 and 6×1014 ions/cm2, respectively) was carried out to construct channel stripes on the planar waveguide surface that has been deposited by a specially designed photoresist mask. The two-dimensional cross sectional refractive index profile of the channel waveguide was reconstructed by considering the shape of the channel waveguide as well as the index distribution of the planar waveguide.