平坦宽带混沌激光的产生及同步

Flat broadband chaotic carrier generation and synchronization

利用光纤环长外腔光反馈半导体激光器产生了频谱平坦的宽带混沌激光,其对应的激光频谱可有效地隐藏外腔的谐振频率,增加了系统的保密性.通过单向耦合方式,将产生的混沌激光注入到另一个参数相近的半导体激光器中,实现了平坦宽带混沌同步输出,两同步激光器输出的相关系数达到0.84.同时实验研究了注入强度和主从激光器的频率失谐对同步质量的影响,结果表明在强光注入锁定下,在很大频率失谐范围内均可实现同步,而且注入强度越大,主从激光器输出的相关系数越大,维持混沌同步所允许的频率失谐范围越大.

The chaotic carrier with smooth spectrum and broad bandwidth is generated by a distributed feedback （DFB） semiconductor laser subject to unidirectional fiber ring optical feedback. The smooth spectrum of the obtained chaotic carrier hides the external cavity resonance frequency peak, therefore the security of the system is enhanced. By unidirectional coupling, we implement the stable chaos synchronization when the chaotic light is injected into a solitary DFB laser diode. The correlation coefficient of synchronization is 0. 84. The effects of injection strength and optical frequency detuning on synchronization are investigated experimentally. The results show that in conditions of strong injected locking the synchronization can be achieved in a large range of frequency detuning, and the stronger injection corresponds to the larger range of frequency detuning in which chaos synchronization maintains. The synchronization quality improves with the injection strength increasing.