Natural noise and jaggedness of the emission spectrum of a multimode solid-state laser

A theoretical study is made of the influence of the shot noise in the process of emission and absorption of photons on the statistical properties of a multimode solid-state laser. It is shown that at all stages of lasing the fluctuations Δn_l of the number of photons n_l in the individual modes are large: Δn_l~n_l. The emission spectrum is then very jagged because of a weak correlation between the individual modes. These conclusions are in agreement with the results of published experimental data.