Active optical gyrometer employing a phase conjugation

An active conjugation ring gyrometer with an optical bias, comprising:

• three main mirrors arranged so as to form a closed geometrical path therebetween, a resonant cavity being defined within said closed geometrical path;
• a cell mounted in said cavity and containing a non-photorefractive type optically non-linear medium;
• laser means for producing two pumping laser beams and for directing said two pumping laser beams in a colinear, oppositely directed manner to irradiate said medium;
• means for modulating the intensity of at least one of said two pumping laser beams to produce an optical bias;
• said medium defining a means for producing, from said two pumping laser beams, a coherent auto-oscillation of two conjugated counter-rotative waves by way of a four wave mixture without electrical excitation of said medium;
• interference means for causing interference of said two counter-rotative waves;
• and
• means for detecting a beat produced by said interference of said two counter-rotative waves.