Emission of optically coupled semiconductor lasers

The emission characteristics of a system consisting of two coherently coupled semiconductor lasers are studied. It is found that different lasing regimes are realised in the system depending on its parameters. In the case of strong coupling, deep stochastic pulsations of the radiation intensity are formed in certain ranges of frequency detuning. There exist critical pump currents above which fluctuations are observed for all detunings and a catastrophic decrease (collapse) in coherence takes place. The power spectrum of noise contains two independent low- and sublow-frequency components. Suppression of noise in a system with spectrally selective coupling is obtained.