Stability and self-stabilisation of single-frequency lasing in a semiconductor laser

The problem of stability of single-frequency lasing is considered using a model including one lasing mode and two nearest subthreshold modes. It is shown that, the parametric interaction of the laser and subthreshold modes, due to the electron concentration beats at the intermode frequency, can cause the self-stabilisation of the single-frequency lasing regime, in which the laser frequency detuning with respect to the spectral gain maximum can exceed the mode interval, and spectral hysteresis can be observed.