Electronic circuits for chaos and synchronization in laser physics

The introduction of electro-optical feedback in lasers has been a major advancement in laser physics. While feedback circuits are commonly used to stabilize the output power and the emission frequency, they can also be utilized to induce chaotic behavior within the laser. About 40 years ago it was discovered that a simple feedback circuit with a bias signal could destabilize a laser and lead to chaotic emission. From a dynamical system perspective, the laser with feedback is described by three nonlinear differential equations involving three variables that represent the laser intensity, the population inversion, and the feedback voltage [1]. The electronic simulation of this kind of laser systems provides surrogate systems that can be used to investigate the control and manipulation of chaotic behaviors. By carefully selecting control parameters specific to the laser type and pump mechanism, it is possible to achieve chaotic dynamics that are highly sensitive to initial conditions [2]. The electronic circuitry enables the exploration of two types of chaos: local chaos, where the transition to chaos occurs through sub-harmonic bifurcations (SC), and global chaos, associated with homoclinic orbits (HC). Global chaos is characterized by pulses of nearly uniform height but showing irregular intervals between them. In this work, a laser is modeled by using electronic components and to synchronize two independent and chaotic systems. The simulation involves adjusting the coupling strength between two electronically simulated lasers [3]. This work also demonstrates the flexibility of the circuit proposed whose it allows, by further minor changes, the showcasing of the dynamics possible of laser with modulation.