Distributed-Bragg-reflection properties of segmented KTP waveguides

Abstract

Segmented KTP waveguides designed for quasi-phase-matched frequency doubling have a periodic variation in the refractive index that acts as a distributed Bragg reflector (DBR). We have measured reflectivity spectra for both TM and TE modes in various segmented KTP waveguides. A reflectivity as high as 70% was observed in a periodically poled KTP waveguide. Reflection bandwidths were typically 0.03–0.06 nm, depending on the length of the sample. The measured temperature tuning rate of the DBR wavelength was 0.017 nm/°C.