Thermooptic switch based on photonic-crystal line-defect waveguides

A thermooptic switch with a symmetric Mach-Zehnder interferometer structure was demonstrated with silicon photonic-crystal-slab line-defect waveguides. The device size was as small as 160×65 μm. The optic switch operated at a wavelength of 1550 nm, and an extinction ratio greater than 30 dB was obtained by 120-mW heating (switching) power over the wavelength range of 15 nm. The switching on-off response times were about 120 μs.