The field of the invention is that of solid-state laser gyros used in inertial control units. However, there are certain technical difficulties in producing laser gyros of this type that are due partly to the fact that the counterpropagating waves interfere with each other in the amplifying medium. A laser gyro according to the invention comprises at least one solid-state amplifying medium and an optical ring cavity comprising first optical means for imposing a first linear polarization state common to the two counterpropagating optical waves at the entrance and exit of the zone containing the amplifying medium and second optical means for imposing, within the amplifying medium, a second linear polarization state on the first optical wave and a third linear polarization state on the second optical wave, these polarization states being perpendicular. Thus, all the drawbacks associated with interference are eliminated.