Influence of External-cavity Length on the Route-to-chaos of Semiconductor Lasers under Optical Feedback

摘要

This paper investigates influence of the external-cavity length on the route-to-chaos of semiconductor lasers operating under optical feedback. The study is based on numerical solution of a time-delay model of rate equations. The route is period doubling when the ratio of the relaxation frequency to the external-cavity resonance frequency is less than unity. The route is sub-harmonic when the ratio is near above unity, and is quasi-periodic characterized by the compound-cavity frequency and the relaxation frequency as well as their difference when the ratio is far above unity.