Time behavior of the internal Q switching in GaAs lasers under electron-beam excitation

Time-resolved spectra of an internal Q -switching emission of electron-beam-excited GaAs lasers were measured. The spectra shifted to longer wavelengths at the rate of 5.63 A/ns at 85 K. Time-resolves spectra of a normal laser emission were also measured to be shifted to longer wavelengths at the rate of about 0.3 A/ns. This remarkable difference of the spectral shifts can be understood if the former shift is caused by the quasi-Fermi level in the conduction band and the latter shift is caused by thermal effects.