Fig. 1. (a) Schematic structure of the coupling-modulated silicon ring resonator. Inset depicts the cross-sectional view of rib waveguides. (b) Resonance ER change upon modulation. (c) A frequency-doubled microwave signal is generated by beating the ±1st-order sidebands at a PD.

Fig. 2. Evolution of a resonance notch profile with the bias voltage V2. V1 is fixed at 3 V.

Fig. 3. Extracted waveguide effective refractive index change as a function of PN junction bias voltage.

Fig. 4. SR changing with the input microwave power. V1 and V2 are fixed at 3 V.

Fig. 5. Experimental setup for microwave frequency upconversion measurement.

Fig. 6. Output optical spectrum when the critically coupled microring resonator is modulated by a 7 GHz microwave signal with (a) 5 and (b) 10 dBm power. Output electrical spectrum when the input microwave frequency increases from 3 to 9 GHz with (c) 5 and (d) 10 dBm power.

Fig. 7. Modeled and measured SR at various microwave frequencies for 5 and 10 dBm input microwave power, respectively.