Low-frequency intensity fluctuations of c.w. d.h. GaAlAs-diode lasers

The optical-emission fluctuations and the current noise of c.w. d.h. GaAlAs junction lasers have been investigated for the first time in the low-frequency range. In both the optical noise spectra and the current noise spectra, a l/f behaviour has been observed. It was found that a strong crosscorrelation exists between optical-emission noise and forward-current noise. Finally, an optoelectronic feedback method that practically eliminated the relative excess light noise has been demonstrated.