A Simple Thermo-optic Switch of a Slab Waveguide

We report a new simple thermo-optic switch composed of a slab waveguide. The cladding is formed on a substrate using a special polymer J-91) with a positive thermo-optic coefficient, and then the core formed using another polymer PVA) with a negative thermo-optic coefficient. Refractive indices of J-91 and PVA cross at 46.5 degrees C. We fabricated a simple TO switch composed of a slab waveguide. When the waveguide temperature increased up to 60 degrees C, the output power of 0.633 mu m wavelength from the waveguide was measured as 80% of that of room temperature. The reason of extinction is due to the fact that the refractive index of cladding exceeds that of guiding layer by heating.