Effect of temporal nonstationarity on the spectrum of injection lasers

The interaction between multimode operation and spike behavior in semiconductor injection lasers has been studied. On the basis of rate equations, the parameters of the light pulses have been determined. We have shown that the excitation of several longitudinal modes near threshold is due to the nonstationary regime. Theoretically and experimentally, we have found the dependences of the mode´s number within the averaged light spectrum, as well as the broadening of each longitudinal mode as the function of the parameters of the emission. Methods for suppression of intensity pulsations are considered. Single-mode operation has been obtained under suppression of self-induced intensity pulsations with the external optical feedback through a fiber section.