Self-pulsing phenomena in /GaAl/As double-heterostructure injection lasers

Repetitive self-pulsations under CW operation in the frequency range of 200 MHz-2 GHz are observed in many (GaAl)As double-heterostructure injection lasers. About 100 lasers of both low-mesa stripe geometry and with proton-implanted structures have been studied and about half of them exhibited more or less pronounced self-induced pulsations. The experimental results on three typical lasers are discussed more in detail on the basis of existing theories. Self-induced pulsations have often been observed in the nonlinear region of the laser light output characteristic. The most probable reason for the instabilities appears to be a repetitive Q-switching process.