Stability Limit of a Semiconductor Laser With Optical Feedback

This paper presents comprehensive studies on the stability of a semiconductor laser (SL) with external optical feedback. In particular, based on numerical computation on the Lang and Kobayashi equations, the stability limit under the condition of minimum linewidth is investigated, revealing how it is influenced by three major parameters associated with SL operation conditions, including the feedback strength (k), the external cavity length (L), and the injection current (J). In contrast to existing work in literature, the presented removed all the approximations and assumptions, hence resulting in relatively complete description of the stability limit. This paper presented leads to a number of important and interesting discoveries: 1) the possible stable area is broader than what is described by the existing work; 2) for long external cavities, the stability limit can be described by a linear relationship between k and L; and 3) on the stability limit, the critical feedback strength (k_c) and critical external cavity length (L_c) are discovered, respectively, being proportional and inversely proportional to J and k.