Enhancing optical-feedback-induced chaotic dynamics in semiconductor ring lasers via optical injection

Abstract

In this paper, we investigate the possibility of using optical injection to efficiently suppress the time-delay (TD) signatures of chaotic signals in a large experimentally accessible parameter range of semiconductor ring lasers (SRLs). We also study how this optical injection can improve the signal bandwidths. The injection signal is obtained from a master SRL with either optical self-or cross-feedback. For optical self-feedback configurations, it is found that the suppression of TD signatures is similar to what has been found in injected Fabry-Perot semiconductor lasers, i.e., narrow range of parameters with respect to the detuning and injection strengths. For cross-feedback configurations, however, the TD signatures can be suppressed in a wide range of parameters meanwhile the bandwidths are significantly improved for the same range of parameters. This is particularly useful for the security in chaos-based communications and also for generating random bits with improved properties.

Wideband complex-enhanced chaos generation using a semiconductor laser subject to delay-interfered self-phase-modulated feedback

“…The dynamics of the ECSL in the proposed scheme are described by the modified Lang-Kobayashi rate equations, by taking into account self-phase modulation and delay-interfered optical feedback [21][22][23]27,38]. The rate equations of the slowly-varying complex electric field E and the corresponding carrier number N in the active region of the ECSL are written as:…”

“…On the other hand, since the conventional feedback light is a linear replica of the laser output, the external cavity resonation introduces a periodicity in the chaos, which results in an obvious time delay signature (TDS) that indicates the feedback delay time of the external cavity. The TDS can be easily identified by several methods, such as the calculations of autocorrelation function (ACF), digital mutual information (DMI), and permutation entropy (PE) [18][19][20][21]. The obvious TDS degrades the randomness of RBG, threats the privacy of chaos sources in secure communication applications, and degrades the precision of chaotic radar.…”

Security-enhanced chaotic communications with optical temporal encryption based on phase modulation and phase-to-intensity conversion

“…At the receiver end, the compound signal is firstly decrypted by the OTD module, and then the WDM modulated chaotic carriers (chaos + message) are derived from the decrypted signal and used for final message decryption. To numerically explore the dynamics of the ECSLs, the well-known Lang-Kobayashi rate equations are adopted, whose complex electric field amplitude E(t) and the intra-cavity carrier number N(t) of the MSL are written as [3][4][5][19][20][21] () 11 (1 )…”

A Multiple-Input Multiple-Output Reservoir Computing System Subject to Optoelectronic Feedbacks and Mutual Coupling

“…The higher dimensional computation for the emerging artificial intelligence can be realized due to RC with the simple hardware structure and the short-time training algorithm. Compared with the approach of realizing artificial neural networks on a personal computer by a software, the RC can be implemented by hardware and can improve the performance of traditional artificial neural networks [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ].…”