Stable locking phase limits of optically injected semiconductor lasers

The stability of an optically injected laser is considered theoretically with an emphasis on the understanding of the locked phase whereas previous works focus primarily on the frequency detuning limits. Exemplary photon and carrier number curves for regions within and outside stable locking are presented. The dependence of the phase limits on injection ratio naturally divides into three regions with qualitatively different descriptions for the phase boundaries in each. Frequency detunings at which the locked phase is zero for different injection ratios are investigated. Using this zero phase point it is shown that the coupling rate between the injected and internal field as well as the linewidth enhancement factor can be determined in a single voltage measurement under weak injection. The modulation response parameters at these detunings are analysed and shown to be strongly interconnected.