Carrier diffusion effects on quantum noise spectra in long wavelength BH lasers

We report experimental and theoretical investigations on quantum noise fluctuations in the microwave frequency range on InGaAsP/InP BH lasers (1.3 and 1.5 μm wavelengths), taking into account lateral carrier diffusion. The theoretical analysis shows that carrier diffusion effects play an important role in the noise behavior (in particular, predicting a smoothed noise resonance-like peak), and that the RIN peak height at constant frequency is minimum when the stripe width is around the carrier diffusion length. These theoretical results are in good agreement with experimental observations up to 4 GHz, performed with an automated noise measurements system.