Noise investigation of CW and mode-locked harmonic cavity nanolasers

We theoretically investigate the noise properties of harmonic cavity nanolasers by introducing a model of coupled equations of evolution of the modes, taking spontaneous emission into account. This model is used to predict the noise among the nanolaser Hermite-Gaussian modes, both in continuous wave and mode-locked regimes. In the first case, the laser noise is described in terms of noise modes, thus illustrating the role of the laser dynamics. In the latter case, this leads to the calculation of the fluctuations of the pulse train parameters. The influence of the different laser parameters, including the amount of saturated absorption and the Henry factors, on the noise of the mode-locked regime is discussed in details.