双光反馈半导体激光混沌高复杂度优化分析

基于排列熵(PE)分析,提出了一种基于半导体激光器(SL)在双光反馈作用下获取高复杂度混沌激光的方案。仿真结果表明,当两个光反馈的延迟时间近似相同、而差值约为激光器弛豫振荡周期一半时,混沌光的PE特征值达到最大,具有最高的复杂度。调节双光反馈的强度值,混沌光的PE特征值将随反馈强度的增加而首先快速增大,然后再缓慢降低。在一定优化双光反馈强度值范围内,PE特征值可取得最大值,从而得到高复杂度的混沌光输出。与单光反馈SL系统相比较,在不同反馈强度下,双光反馈系统所获得的混沌光的PE特征值也总是大于单光反馈系统的结果。

Optimization Analysis on Complex Degree of Optical Chaos in a Semiconductor Laser with Double Optical Feedback

By adopting the permutation entropy (PE) analysis, a high complex optical chaos generation scheme based on a semiconductor laser (SL) with double optical feedbacks is proposed. The simulated results show that, when the delay times of two optical feedbacks are close to each other, and have a difference of about a half of the SL relaxation oscillation period, the characteristic value of PE reaches a maximum, and the most complex chaotic output can be obtained. With the increase of the strength of two optical feedbacks, the characteristic value of PE firstly experiences a rapid increasing process and then decreases gradually. Thus, the high characteristic values of PE and high complexity chaos output can be founded within a certain range of feedback strengths. Moreover, under different feedback strength settings, the characteristic value of PE for double optical feedback system is always higher than that for single optical feedback system.