Influence of polarization-selected mutual injection on the polarization-switching dynamics of vertical-cavity surface-emitting lasers

Abstract

Influences of polarization-selected mutual injection on polarization switching behaviors of vertical-cavity surface-emitting lasers (VCSELs) are investigated numerically. For the polarization-preserved (PP) injection, the x mode is selected and is injected mutually into the two lasers. The two lasers show nearly identical polarization-switching (PS) behaviors, even if frequency detuning is nonzero. For the polarization-rotated (PR) injection, the x mode is selected and rotated 90° before being injected into the two lasers. When frequency detuning is considered, the two lasers show totally different PS properties, and mutual injection will switch to unidirectional injection with varying parameters. In both the cases of PP and PR injection, the partitions that correspond to different emission states and the switching points of the two VCSELs are mapped in the parameter space of injection rate and bias current. Furthermore, for each different emission state, the output dynamics and synchronization performance are evaluated in the time domain.