Complexity Analysis in A Semiconductor Laser with Time-Delayed Optical Feedback

Abstract

We investigate the complexity of chaotic temporal dynamics in a semiconductor laser with time-delayed optical feedback. The Lang-Kobayashi equations with gain saturation are used to observe chaotic instabilities. To evaluate the complexity of chaos, the Lyapunov spectrum is numerically obtained from a set of linearized equations, and Kolmogorov-Sinai (KS) entropy and Kaplan-Yorke (KY) dimension are calculated. The dependence of the KS entropy and the KY dimension on variable laser parameters are also investigated. The complexity analysis techniques can be useful for designing physical random number generators with chaotic lasers.