Rb/Ba side-diffused ridge waveguides in KTP

Opt Express. 2017 Aug 21;25(17):19872-19877. doi: 10.1364/OE.25.019872.

Abstract

We report on characterization of ridge waveguides fabricated in KTP (KTiOPO4) by use of diamond-blade dicing and Rb/Ba ion exchange. The waveguides were prepared in substrates that have their z-axis in the surface plane, perpendicular to the waveguide direction. This hinders the RbBa ions from diffusion into the depth, as they are only mobile along the z-axis, and improves the waveguide's resistance against elevated temperature. Attenuation coefficients of 0.3 dB/cm (0.4 dB/cm) for TM (TE) polarization were measured at 1060 nm wavelength. Internal conversion efficiency of up to 3.3%/(W cm2) was determined for type-II SHG of 1064 nm.