Nonlinear nonreciprocity effects in a ring laser placed in a longitudinal magnetic field

Calculations are made of nonreciprocity effects (intensity difference and difference between the frequencies of the opposite waves) which depend on the excess over the stimulated emission threshold and occur in a helium-neon ring laser with quasilinearly polarized modes on application of a longitudinal magnetic field to the active medium. Analyses are made of single-isotope and equi-isotopic active media. It is shown that the amplitude and frequency nonreciprocities are governed by the difference between the polarizations of the opposite waves. Allowance for resonance radiation trapping has a substantial influence on the nonlinear nonreciprocity effects.