Investigation of photosensitive properties of an injection laser by the effective gain method

The results are given of a theoretical analysis of the effect of external radiation on electrical characteristics of an injection laser. The calculations are based on a model of a laser with a quasihomogeneous behavior of the gain profile. An effective gain is introduced in the calculations: this approach allows for the resonant nature of the amplification process and makes it possible to extend the solutions of simple rate equations for the mode-free case to the whole spectrum of longitudinal modes. The photoelectric signal is determined under amplifying and lasing regimes. An analysis is made of the evolution of the photosensitivity spectrum on increase in the current and it is shown that a single narrow-band sensitivity line of width ~1GHz can be selected (superselectivity effect). Calculations are made of the threshold current in the superselectivity regime and some methods are suggested for the determination of the parameters of laser structures.