利用半导体激光器的混沌同步有望实现高速物理随机密钥分发,然而激光器的混沌同步恢复时间限制密钥分发的速率。为此数值研究垂直腔面发射激光器(VCSEL)在开环注入锁定同步系统中,影响混沌同步恢复时间的因素。模拟结果表明,可以通过三种途径缩短混沌同步恢复时间,增加激光器的偏置电流、微分增益系数,或减小光子、载流子寿命来缩短弛豫振荡周期;减小线宽增强因子来减小激光混沌的复杂度;增加注入强度、减小频率失谐来实现强注入锁定。研究结果对提高基于混沌激光同步的密钥分发速率具有理论借鉴的意义。

Chaos synchronization using semiconductor lasers achieves high-speed physical-layer key distribution, but the chaos synchronization time of lasers limits the rate of key distribution. Consequently, the factors affecting the chaos resynchronization time in an open-loop injection-locked synchronization system of the vertical-cavity surface-emitting laser (VCSEL) have been numerically studied. Moreover, the experimental results demonstrate that the chaos resynchronization time can be reduced in three ways: increasing the bias current of the laser and the differential gain coefficient, or reducing the photon and carrier lifetime to shorten the relaxation oscillation period; reducing the linewidth enhancement factor that can reduce the complexity of laser chaos; and increasing the injection intensity and reducing the frequency detuning, which can achieve strong injection locking. Based on chaos synchronization, the results have theoretical reference significance for improving the key distribution rate.