Fig. 1. (a) Transmission spectrum of the microring modulator at different voltages. (b) Modulated signal at the optimal working point.

Fig. 2. Experimental setup for a W-band IM-DD wireless communication system based on the photonic integrated circuit (PIC). (a) On-chip dual-mode DFB laser. (b) PIC containing a single microring modulator and ring resonators. (c) PIC containing cascaded microring modulators. (d) High-speed photodetector with a W-band transmitting antenna. (e) Envelope detector with a W-band receiving antenna.

Fig. 3. Dual-mode and single-mode of integrated DFB laser at different input currents.

Fig. 4. Optical transmission spectrum of the on-chip ring resonator.

Fig. 5. (a) Eye diagram before wireless transmission. (b) BER of using different optical sources versus input optical power.

Fig. 6. Transmission spectrum of cascaded microring modulators at different voltages.

Fig. 7. (a) Spectrum of two lasing modes before and after modulation. (b) Waveform comparison without wireless transmission. (c) BER versus input optical power. (d)–(f) Eye diagrams without processing. (g)–(i) Eye diagrams with FFE equalizing.