Ultra-compact electro-thermally tunable photonic crystal prism for on-chip optical router application

We report design, fabrication and characterization of MEMS enabled electro-thermally tunable 2D photonic crystal prism. The tunable photonic crystal prism was realized by utilizing thermo-optic effect of silicon. A nickel chromium heater was used to heat up the photonic crystal prism. The localized heating on the prism (to 222°C) modifies the photonic band structure, leading to an angle shift (4°) of the propagation direction of light. The tunable prism was characterized using a far field imaging infrared camera. The profiles of the scattered light spot at the end tip of the output waveguides clearly showed angle shift of the propagation of the light as expected. Both electromagnetic simulation and experiment results were in good agreement.