Characteristics of microwave photonic signal generation using vertical-cavity surfaceemitting lasers with optical injection and feedback

Characteristics of microwave photonic signal generation based on the period-one dynamic in an optically injected vertical-cavity surface-emitting laser are studied systematically. The evolutions of the linewidth, power, and second-harmonic ratio of the generated microwave are investigated as a function of injection strength and frequency detuning. The effect of optical feedback on the linewidth and the phase noise of the generated microwave photonic signal is also studied in detail. With the help of optical feedback, the linewidth can be effectively reduced by increasing the feedback strength and feedback delay time. However, there is an optimal feedback delay time to minimize the phase noise.