A new design of 1×2 optical switch with silicon waveguide and phase change material

Abstract

On chip photonics devices relying on the weak, volatile thermo-optic or electro-optic effect of silicon usually suffer from high energy consumption and low refractive index coefficient. In this paper, we designed a 1×2 phase change optical switch. The device is implemented in two silicon waveguides system using an overcladding layer of the phase change data storage material Ge2Sb2Te5 (GST), which exhibits high contrast in its optical properties upon transitions between its crystalline and amorphous structural phases. The switch shows cross-state and bar-state corresponding to amorphous GST (a-GST) and crystalline GST (c-GST), respectively. The characteristic parameters of the switch were carefully designed and simulated by three-dimensional finite-difference time-domain (3-D FDTD) method. As the simulation result, the insert loss was less than 0.5 dB. The crosstalk was -16 dB for cross-state and -29 dB for bar-state at 1550nm.The device performance can be further optimized and the low consumption phase change optical switch can be expected for future optical communication networks.