INVESTIGATION OF CHAOTIC SEMICONDUCTOR LASER RADIATION DURING OPTICAL INJECTION

The paper is devoted to the experimental study of chaotic radiation generated in a system of two semiconductor lasers during optical injection. The aim of the work was to identify optimal conditions for the occurrence of chaotic oscillations and analyze their dynamics depending on key parameters – the injection coefficient and frequency disorder. The relevance of the work is due to the need to develop advanced random number generators for cryptographic information security tools, where true randomness based on unpredictable physical processes is critically important. Section 1 examines the principles and features of optical injection. Research on synchronization and detuning of master and slave lasers is analyzed. Section 2 describes the design and conditions of the authors' experiment. Section 3 presents the results. Section 4 discusses potential applications of chaotic laser radiation. During the experiments, a circuit with an optical circulator was used, which provides an effective unilateral effect of the master laser on the slave. The boundaries of the zones of dynamic modes were experimentally determined and illustrated: stable frequency capture, period-one and period-two oscillations. It has been found that the smoothest transitions to the chaotic mode, which is of the greatest interest for creating RNGs, are observed with positive frequency detuning. Spectral analysis has recorded a pattern characteristic of chaos with multiple peaks, which confirms the random nature of the radiation. The results obtained are fully consistent with the data of other reputable studies, which indicates the correctness of the methodology. The practical significance of the work lies in demonstrating the prospects of using chaotic radiation from semiconductor lasers as a reliable physical source of entropy for truly random number generators in demand in modern encryption systems, quantum communication and information security, which is especially important in the context of digitalization and increasing data security requirements.