Ring laser having magnetic isolation of counter-propagating light waves

Abstract From the Canadian patent

A ring laser having a nonreciprocal loss element positioned in the aperture of the optical cavity of the laser. The nonreciprocal loss element is adapted to isolate a pair of plane-polarized counter-propagating light waves from each other. The isolation reduces the coupling between the waves and thereby reduces the extent of nonlinear mode locking which typically occurs in ring laser gyroscopes when the difference in frequency between the light in the two waves is small. The isolation is the result of either a spatial or a temporal separation between the counter-propagating light waves. The nonreciprocal loss element of the preferred embodiments comprises a first optical element having …