Experimental and Numerical Study of Locking of Low-Frequency Fluctuations of a Semiconductor Laser with Optical Feedback

We study the output of a semiconductor laser with optical feedback operated in low-frequency fluctuations (LFFs) regime and subject to weak sinusoidal current modulation. In LFF regime, intensity exhibits abrupt drops, after which it recovers gradually. Without modulation, drops occur at irregular times, while, they can lock external modulation occur, depending on parameters, every two or three cycles. Here, we characterize experimentally locking regions use well-known Lang–Kobayashi model simulate dynamics. analyze effects several parameters find that simulations are good qualitative agreement experimental observations.