Narrow Linewidth Photonic Microwave Generation Based On 1550 Nm Vertical-cavity Surface-emitting Laser Subject To Optical Injection

The Radio-over-Fiber(RoF)is a new technology that effectively combines wireless communication with optical fiber communication.RoF has shown the huge development potential in the high-speed development communication system,because it has many advantages such as strong confidentiality,wide coverage,low cost and so on.As one of the key technologies of RoF technology,the generation of high performance photonic microwave has become a research hotspot of related scholars.Among the numerous photonic microwave acquisition schemes,photonic microwave acquisition scheme based on period-one dynamical presented by an Edge Emitting Semiconductor Lasers(EESLs)with optically injection have received additional attention.The method can not only generate microwave has high frequency,but also the microwave has single sideband spectral structure,but the microwave signal linewidth is wide,it needs to further introduce frequency stabilization techniques for narrowing.Compared with EESLs,vertical cavity surface emitting lasers(VCSELs)have some characteristics of low threshold,single longitudinal mode and small size,so microwave generation scheme based on an optically injected VCSELs has more application prospects.In this paper,we propose a scheme that based on the period-one dynamical state emerging in a 1550 nm vertical-cavity surface-emitting laser(1550 nm-VCSEL)with parallel optical injection,high-quality photonic microwave is acquired after further introducing optoelectronic negative feedback.1550 nm-VCSEL subject to parallel polarized optically injection can exhibit rich nonlinear dynamics behaviors including stable injection locking(SIL),period-one(P1),period-two(P2),chaos(CO)by adjusting injection strength and injection frequency.For a particular frequency detuning,the 1550 nm-VCSEL can exhibit P1 oscillation in the larger injection power range.A photonic microwave with single sideband structure and frequency exceeding 10 GHz can be generated for 1550 nm-VCSEL under appropriate injection parameters,but the linewidth of the microwave signal is in the order of MHz due to the presence of inherent phase noise in the laser,it is limited in the long distance signal transmission communication systems.The photonic microwave linewidth can be narrowed after introducing optoelectronic feedback,the reason is locking effect of delayed repetitive microwave signal on P1 oscillation in optoelectronic feedback loop.In addition,under the optimized feedback strength,the frequency-tunable narrow linewidth microwave signal can be obtained by varying the injection strength.