Polarization Switching Characteristics of 1550-nm Vertical-Cavity Surface-Emitting Lasers Subject to Double Polarization Pulsed Injection

Based on the spin-flip model, the polarization switching (PS) characteristics of two polarization outputs in a 1550-nm vertical-cavity surface-emitting laser (1550-nm VCSEL) subject to double polarization pulsed injection (DPPI) are investigated theoretically, and the obtained results are compared with the case, in which the 1550-nm VCSEL is simultaneously injected by the pulses of orthogonal polarized light and a continuous wave (CW) parallel polarized light, which is called double optical injection with pulsed orthogonal polarization (DIPOP). The simulated results show that, compared with the DIPOP, the DPPI method is beneficial to improving the PS performance under suitable parameters. The influences of the timing difference (Δt) in the switching of two injection pulses on the PS performance of 1550-nm VCSEL subject to DPPI are analyzed, and the optimized values of At under different bias currents are determined. Furthermore, for optimized At, the dependences of the switching times on the amplitudes of two polarization pulses and the frequency detuning are given.