基于SOI的Mach-Zehnder型热光可变光衰减器的设计

Mach-Zehnder type Thermo-Optical Variable Optical Attenuator (TO-VOA) was carefully designed based on Silicon-On-Insulator (SOI) single mode rib waveguide. Finite Difference Beam Propagation Method (FD-BPM) simulation was presented to optimize the devices’ parameters at the wavelength of 1550nm. The optimum electrode length of 150µm was obtained. The dynamic attenuation range from 0.1dB to 40dB was achieved by very small refractive index variation (0~5.3×10-3)and the corresponding temperature variation is 0~30℃. Finite Element Analysis (FEA) was used to simulate the steady-state and dynamic temperature response. Because the self-heating effect of SOI was enhanced by using double ridge structure, the max power consumption is only 57mw.The response time is about 100us, which makes the proposed device able to operate in the range of 10 kilohertz. The device，designed for low-cost photonic applications, could be easily used as the basic unit to fabricate multi-channel VOA and integrated in silicon optoelectronic circuits.