Electro-optical tunable time delay and advance in silicon microring resonators.

We demonstrate electro-optical tunable time delay and advance in a silicon-microring-resonator-based notch filter integrated with a lateral p-i-n diode. We tune the time delay and advance by controlling the coupling regimes from over- to under-coupling through carrier-injection-based free-carrier dispersion effect. We measure maximum time delay and advance of approximately -95 and approximately 96 ps near critical coupling, with bandwidths of approximately 3.5 and approximately 3 GHz, upon dc power consumption in the range of 1 mW. We model the transmission spectra and time delay/advance using the transfer-matrix method and analyze the time-intensity and time-bandwidth products, which show good agreement with our measurements.