研究了光反馈、光相位调制和外部光注入三种混沌激光系统的延时特性和有效带宽,分析比较了延时特征峰的强度大小、周期特征和带宽宽度以及三种系统应用于保密光通信系统中的优缺点。基于实际应用,对光注入混沌激光系统时多个物理参数对延时特征峰和有效带宽的影响进行深入研究,发现通过调整驱动激光器外腔时延和注入时延拓展保密系统参数空间具备可行性,匹配合适的反馈强度和注入强度既能有效抑制延时特征峰,又能增大其有效带宽。

The time-delay characteristic and effective bandwidth of three chaotic laser systems including optical feedback, optical phase modulation, and external laser injection systems are studied. The intensity, periodic characteristic, and bandwidth of the time-delay characteristic peak are analyzed and compared. The advantages and disadvantages of the three systems applied to the confidential optical communication system are discussed. Based on practical applications, the influences of several physical parameters of the optical injection chaotic laser system on the delay characteristic peak and effective bandwidth are studied in depth. We find that it is feasible to expand the parameter space of the confidential system by adjusting the external cavity delay and injection delay of the driving laser. By matching the appropriate feedback intensity and injection intensity, the time-delay characteristic peaks can be effectively suppressed, and the effective bandwidth can be enlarged.