Broad tunable photonic microwave generation in an optically pumped spin-VCSEL with optical feedback stabilization

We propose and numerically demonstrate a photonic microwave generation scheme based on the dynamic period-one oscillation of a solitary spin-polarized vertical-cavity surface-emitting laser (spin-VCSEL). The evolution of the oscillation amplitude, frequency, power, and linewidth of the generated microwave is systematically investigated by using two-dimensional maps. The results show that the generated microwave signals with a dominant linewidth of about 3 MHz have a broad tunable frequency (from several gigahertz to hundreds of gigahertz), which benefits from the birefringence-induced oscillation in spin-VCSELs. Moreover, with the help of optical feedback, the microwave linewidth can be effectively minimized (∼51kHz) by increasing the feedback strength and feedback delay time. Importantly, this Letter offers prospects for applications requiring a feasible and resource-efficient microwave source in microwave photonic fields.