Industrial Automatic Control Systems and Controllers Annotation << Back Algorithm for Determining the form Factor of a Gas Laser in the Advanced Generation Mode V.S. Belyy This scientific article is devoted to the determination of the form factor of a gas laser by the calculation method. The result of the work is a typical algorithm for determining the equation of the spectral line of laser radiation for the developed generation mode with the given example of solving the problem of determining the form factor of a gas laser on the example of a helium-neon laser. The algorithm given in the article can be used as the basis for methods for determining the spectral density of laser radiation by the calculation method when designing gas lasers. The article shows that for a gas laser in the advanced generation mode, when the number of photons in the resonator mode is sufficiently large, and the amplitude and phase fluctuations are independent, while the phase changes are random and have a normal distribution, the equation of the envelope of the radiation spectrum is the result of a direct Fourier transform of the two-dimensional correlation function of the signal component of radiation, the amplitude of which is determined by the total amplitude of photons in the resonator mode. Keywords: gas laser; resonator mode; two-level system; Rabi frequency; advanced generation mode; population inversion; amplitude and phase fluctuations; phase diffusion; form factor; radiation spectrum. DOI: 10.25791/asu.11.2021.1324 Pp. 12-17.