Experimental investigation of nonreciprocal effects in a ring laser with a transverse magnetic field applied to the active medium

Nonreciprocal effects in a helium–neon ring laser, which arise when a transverse magnetic field is applied to the active medium, were discovered and investigated in detail. One of these effects appears because, due to a difference between the polarization characteristics of counterpropagating waves, the anisotropy of the saturation of the medium in a magnetic field is also different for the two directions. The effect is nonlinear. The second effect is produced by the action of a transverse magnetic field on the drift of the active atoms in a dc discharge. The effects discovered depend on the square of the magnetic field.