Investigation of fluctuations of the frequency of a helium-neon laser emitting at λ = 0.63 μ in the technical part of the spectrum

The results are given of an experimental investigation of the spectral density of fluctuations of the frequency of two single-mode lasers. The output frequencies of these lasers were shifted relative to one another by an automatic control system. The known characteristics of the control system were used in a linear-approximation calculation of the spectral density of the laser frequency under free-oscillation conditions. The spectral properties of some of the mechanical elements of the laser unit were investigated.