He-Ne laser gain dependence on discharge current and gas pressure from resonant Faraday effect

It is analyzed the influence of a longitudinal magnetic field on the operating mode of a He-Ne laser, knowing that the magnetic field is used for the suppressing of the (lambda) 3.39 micrometers , which is amplified in the same time with (lambda) 632.8 nm. It was used the Faraday magneto-optic effect at resonance, so that eh (lambda) 632.8 nm He-Ne laser radiation travels through a Ne-Ne mixture, with the pressures ratio pHe/pNe equals 5, in population inversion conditions, placed in a longitudinal magnetic field. It was studied the laser medium amplification coefficient dependence on the parameters: discharge current intensity and total gas pressure. For the relation between the rotation angle of the polarization plane in a magnetic field and the laser amplification coefficient, in the He-Ne mixture, it was found a linear theoretical dependence. By fitting the experimental data, there are obtained nonlinear dependencies, for (alpha) (p) and (alpha) (I), which can be explained in the atomic collisions theory.