研究了偏振选择互注入条件下半导体激光器的同步和混沌滤波效应。将单模互注入速率方程扩展为包含两个偏振态的理论模型, 并选择X偏振态作为互注入形式, 不仅为激光器产生混沌和实现同步提供了条件, 还可以完全抑制Y偏振光, 实现了纯偏振模式同步。通过频率失调的引入, 保持了激光器主从地位的稳定。研究结果表明, 主从激光器实现了时差等于注入延时的混沌同步, 输出功率表现出高频振荡并伴随有对称性破坏现象。对主激光器进行调制时, 同步系统表现出与单向注入相似的混沌滤波效应; 对从激光器进行调制时, 系统的混沌滤波效应并不明显。

Systems of mutually coupled semiconductor lasers are widely used in optical chaos communication, spread spectrum communications and high power emissions. The chaos pass filtering effect and synchronization behaviors of mutually coupled semiconductor lasers are studied numerically in this paper. Single-mode rate equations are extended to two polarization modes. By selecting X-polarized mode for mutually coupling, not only chaotic dynamics and synchronization are obtained, but also Y-polarized modes are totally restrained, so pure polarization mode synchronization is realized. A frequency detuning is introduced to keep the first laser as a leader. Simulation results show that outputs of the leader and laggard lasers exhibit high frequency fluctuations in company with symmetry breaking and they are synchronous with a lag equal to the external delay. The system shows similar chaos pass filtering effect to unidirectionally coupled semiconductor lasers when the leader is modulated, while chaos pass filtering is bad when the laggard is modulated.