Intrinsic fluctuations in the output intensity of double-heterostructure junction lasers operating continuously at 300°K

Abstract

Measurements of the intrinsic noise fluctuations in the light intensity from a stripe-geometry double-heterostructure junction laser operating continuously at room temperature are reported. The frequency spectrum of the fluctuations has been measured from 10 MHz to 4 GHz for currents both above and below threshold. The above-threshold noise spectra show the resonant peak due to excitation of the spiking resonance by the quantum shot noise intrinsic to the lasing process. Near threshold the frequency of this resonance varies between 200 and 1000 MHz as a function of laser current. In addition, as the pumping current is increased above threshold, the low-frequency (< 100 MHz) noise shows the pronounced reduction expected of an amplitude-stabilized oscillator. However, over the same range of currents, the high-frequency (> 2 GHz) noise continues to increase in apparent contradiction with theoretical predictions.