Analysis of intensity fluctuations in a junction laser with low quantum-efficiency regions

Fluctuation spectra due to quantum shot noise in the output from a junction laser are calculated using rate equations for a non-uniform double-sectioned laser with a low quantum-efficiency region. The pumping-rate dependence of the fluctuation spectra for the non-uniform model is found to be roughly the same as that for the ordinary uniform model. The degradation process is then simulated using the uniform and nonuniform models, and it is shown that qualitatively opposite changes, decay or growth of resonance phenomena, are ex- pected in the fluctuations as the degradation proceeds uniformly or nonuniformly.