Tunable MEMS Actuated Microring Resonators

A simplified process has been developed to fabricate MEMS tunable microring resonators on six-inch silicon-on-insulator wafers. Deep UV lithography is used to create 220-nm-wide waveguides and microrings. The process is CMOS compatible. The transmission spectra change from a double resonance dip (under-coupling) to a broader single resonance dip (over-coupling) when the waveguide is moved closer to the microring. This is explained by coupled mode theory that includes the effect of backscattering in the microring.