Silicon-Based 2D Slab Nano Photonic Crystal Thermo-Optic Light Modulator

We report a compact (20.9 mum x 20 mum) silicon-based 2D slab nano photonic crystal light modulator tuned by the thermo-optic modulation of the cut-off wavelength about 1,470 nm. Plane wave expansion method (PWEM) and 2D finite difference time domain (FDTD) method were utilized to design a triangular lattice line defect photonic crystal waveguide in 220 nm thick silicon with diameter of 270 nm and pitch distance of 400 nm. Micro heater was situated right next to the line defect photonic crystal to provide localized resistive heating. The device was characterized in the wavelength range of 1,400 nm~1,520 nm. Waveguide mode, cut off mode and photonic crystal mode were found which clearly shows cut-off about 1,470 nm wavelength.