High Thermo-Optic Coefficient of Silicon Oxycarbide Photonic Waveguides

In this Letter, we report on the observation of a high thermo-optic coefficient (TOC) of silicon oxycarbide (SiOC) films deposited by reactive RF magnetron sputtering for integrated photonic waveguides. In the 1550 nm wavelength range, the measured TOC of SiOC is as large as 2.5 × 10–4 RIU °C–1, which is about 30 times larger than that of silica and almost twice that of silicon. Thin films of SiOC have been integrated in germanium-doped silica and silicon oxynitride conventional waveguide technology, achieving a 10× and 3× enhancement of the waveguide effective TOC, respectively. These results demonstrate the potential of SiOC for the realization of highly efficient phase actuators and low-power-consumption thermally tunable photonic integrated platforms.