Low Power-Consumption and High Response Frequency Thermo-Optic Variable Optical Attenuators Based on Silicon-on-Insulator Materials

A novel silicon-on-insulator thermo-optic variable optical attenuator with isolated grooves based on a multimode interference coupler principle is fabricated by the inductive coupled plasma etching technology. The maximum fibre-to-fibre insertion loss is lower than 2.2dB, the dynamic attenuation range is from 0 to 30dB in the wavelength range 1500--1600nm, and the maximum power consumption is only 140mW. The response frequency of the fabricated variable optical attenuator is about 30kHz. Compared to the variable optical attenuator without isolated grooves, the maximum power consumption decreases more than 220mW, and the response frequency rises are more than 20kHz.