注入半导体激光器混沌调制性能与内部相位键控编码方法研究

研究注入半导体激光混沌调制解调及其性能特性，提出外部光注入半导体激光器混沌内部相位编码方法. 小信号调制分析了系统混沌调制响应函数和解调响应函数以及解调因子，系统的调制解调响应函数以及解调因子在60MHz有一个峰值，系统在高频调制时，响应函数和解调因子明显下降. 理论推导出混沌调制解调方程，给出了小信号调制时的信息信号的解，数值分析出系统在低频有一个调制解调峰值，高频调制解调效果下降，但系统仍可以进行10⁹Hz频率调制解调. 数值模拟并证明了系统在较大的参数范围内都能实现同步，模拟了混沌调制速率200Mb/s和调制频率1.4GHz的保密通信应用. 还通过键控调制注入光的相位相移对激光混沌态进行了编码，通过同步与非同步进行混沌解码，数值模拟了具有调制速率10Mb/s的混沌相位键控编码通信应用. 关键词：混沌同步激光器相位

Studies on chaotic modulation performance and internal phase shifting key encoding in injection semiconductor lasers

The chaotic modulation and demodulation in injected semiconductor lasers are studied, and a method of chaotic encoding is presented by modulating the phase of external optical injection light in semiconductor lasers. The modulation response function, demodulation response function and demodulation response factor are analyzed by small-signal analysis. It is found there are peak values about 60 MHz and the response functions and the demodulation factor decrease at high modulation frequency. A chaotic modulation-demodulation equation is theoretically deduced and its roots are given. It is found that there is a peak value at low modulation frequency and the demodulation perfomance declines at high frequency, however, modulation-demodulation of 10⁹ Hz frequency is relalized. Synchronization is achieved and is proved feasible numerically in larger parameter range. Secure communication applications are numerically simulated with chaotic modulations of 200 Mb/s rate and 1.4 GHz frequency. Chaotic encoding is also achieved by shifting key on or off a phase-controller to encode chaotic laser state and decoding is realized under the condition of synchronization or unsynchronization. Chaotic phase key shifting is numerically simulated with a bit rate of 10 Mb/s.