On-Chip Integration of GaN-Based Laser, Modulator, and Photodetector Grown on Si

A preliminary on-chip integration of GaN-based laser, modulator, and photodetector grown on Si is reported. The modulator is integrated into the laser and shares the same InGaN quantum well active region with the laser and the photodetector. By varying the applied voltage to the modulator, the absorption of the modulator can be adjusted due to the changed band bending of the InGaN quantum well active region, and hence the threshold current and the light output power of the laser can be tuned. The photodetector can effectively detect the output power of the laser tuned by the applied voltage to the modulator, which opens up a new way for GaN-based on-chip photonic integration on Si.