Low-power total internal reflection thermo-optic switch based on hybrid SiON-polymer X-junction waveguides.

We propose and demonstrate a low-power 2×2 total internal reflection thermo-optic switch based on an X-junction configuration formed with a silicon oxynitride (SiON) core and polymer cladding. Unlike X-junctions reported thus far, our proposed configuration features a slot formed on the center of the X-junction and filled with polymer cladding. With such a configuration, the opposite thermo-optic characteristics of SiON and polymer and, hence, heat utilization efficiency can be fully utilized. Our fabricated proof-of-principle switch shows extinction ratios of larger than 15.34 dB and switching powers of less than ∼59.6  mW. The rise time and fall time of switching are 1.42 and 0.85 ms, respectively. The insertion losses are less than 10.6 dB for all channels, and the polarization-dependent loss is ∼0.3  dB.