利用频谱仪提取双反馈混沌半导体激光器的外腔长度密钥

Extracting the external-cavity key of a chaotic semiconductor laser with double optical feedback by spectrum analyzer

光反馈半导体激光器产生的高维宽带混沌载波,应用于光混沌通信系统中.激光器的外腔长度用作混沌保密通信的附加密钥.本文实验研究了光反馈混沌半导体激光器外腔长度密钥的识别.通过对长腔光反馈产生的混沌频谱进行局部放大,分析其精细结构,结果表明:无论是单反馈半导体激光器还是有不同外腔长度比的双反馈半导体激比器,都可以利用频谱仪直接提取出激光器的外腔长度信息.

Optical-feedback laser diode has been widely applied in chaotic optical communication,because it can simply generate wideband and high-dimension chaos and its external-cavity length is often regarded as an additional key.In this paper,it is experimentally demonstrated that the time delay signature of a chaotic laser diode with optical feedback can be identificated.Through locally enlarging the power spectrum of chaotic light and observing its fine structure,the external-cavity key can be directly extracted by the spectrum analyzer,regardless of the laser diode with single or dual optical feedback of a different external cavity length ratio.