A micromachined optical double well for thermo-optic switching via resonant tunneling effect

This letter presents the thermo-optic switching characteristics of an optical double-well structure, which has a high-low-high-low-high refractive index construct formed by micromachined silicon prisms and air gaps. Analysis shows such structure features full transmission (i.e., on state) and requires low refractive index change for switching function. The device is fabricated on silicon-on-isolator wafer using deep etching process. In experiment, it measures a switching speed of 1μs and an extinction ratio of 30dB. Compared with the other micromachined switches, this device utilizes different physical principle and processes various merits such as fast switching speed and low power consumption.