Intensity noise in quantum-dot laser diodes

We present intensity noise studies of a self-organized InAs/GaAs quantum-dot laser. The noise power measured for the full emission spectrum was found to be smaller than that for separate longitudinal mode groups. This noise cancellation indicates that the intensity fluctuations of the mode groups were anticorrelated, with typical values of the normalized correlation coefficient of around −0.50. This surprisingly high value is not consistent with the model of the quantum-dot laser as an inhomogeneous ensemble of independent microlasers.