Random-injection-based two-channel chaos with enhanced bandwidth and suppressed time-delay signature by mutually coupled lasers: Proposal and numerical analysis* *Project supported by the Sichuan Science and Technology Program, China (Grant No. 2019YJ0530), the Scientific Research Fund of Sichuan Provincial Education Department, China (Grant No. 18ZA0401), the Innovative Training Program for College Student of Sichuan Normal University, China (Grant No. S20191063609), and

Abstract

Simultaneous bandwidth (BW) enhancement and time-delay signature (TDS) suppression of chaotic lasing over a wide range of parameters by mutually coupled semiconductor lasers (MCSLs) with random optical injection are proposed and numerically investigated. The influences of system parameters on TDS suppression (characterized by autocorrelation function (ACF) and permutation entropy (PE) around characteristic time) and chaos BW are investigated. The results show that, with the increasing bias current, the ranges of parameters (detuning and injection strength) for the larger BW (> 20 GHz) are broadened considerably, while the parameter range for optimized TDS (< 0.1) is not shrunk obviously. Under optimized parameters, the system can simultaneously achieve two chaos outputs with enhanced BW (> 20 GHz) and perfect TDS suppression. In addition, the system can generate two-channel high-speed truly physical random number sequences at 200 Gbits/s for each channel.