Chaos Engineering in Multi-Gigahertz Solid-State Lasers: A Novel Approach to Optoelectronic Control

This paper presents a comprehensive study of a multi-gigahertz chaotic generator of light pulses based on solid-state laser sources, including fiber lasers, governed by carefully designed positive and negative feedback loops. It harnesses the inherent nonlinear dynamics within a solid-state laser controlled by a combination of two inertial feedback loops, enabling the realization of complex chaotic behavior, including the logistic map scenario, under moderate amplification conditions. The laser system dynamics are rigorously investigated through theoretical modeling, employing a nonlinear map approach, and high-resolution picosecond simulations. The results of our numerical simulations highlight the efficacy of fast electro-optical feedback system with adjustable delays and relative loop sensitivity, providing valuable insights into the design and optimization of chaotic light pulse generators for diverse applications, including secure communication and advanced signal processing. The control scheme integrating Self-Starting Harmonic Mode-Locking (SSHML) for generation of multiple short pulses inside the laser resonator incorporates a memory-erasure regime that reduces the response time by eliminating interference from neighboring pulses. Our study focuses on the features of the electro-optic modulation process. We demonstrate that variation of bias voltage significantly influences the required overall gain for nonlinear dynamics onset. We examined the reversal of the bias voltage polarity and found that selecting a zero value is sufficient to significantly reduce the operating gain. Corresponding requirements for the photodiodes of the control system have been defined. As a result, recommendations for selecting optimal control conditions have been developed. Our findings facilitate easier experimental realization of the chaotic generator.