Large intensity noise from symmetric low-Q cavity semiconductor lasers driven with pump-noise-suppressed current injection in the high-pump regime

摘要

We have measured the intensity noise front symmetric low-Q cavity laser diodes (LD's) operated far above threshold in a constant-current mode. The single-sided output noise exhibits significant dependence on the mirror reflectivities of the laser cavity, in good agreement with the theoretical predictions, based on a quantum-mechanical traveling-wave analysis. In an antireflection-coated LD with a residual mirror activity of 5%, intensity noise as large as 9 dB above the shot-noise level was observed at a pumping rate of 10 times the threshold. This is caused by amplification of the vacuum-field fluctuations coupled by the low-reflectivity mirrors into the laser cavity. (C) 1997 Optical Society of America.