Patent ID: 8687198

Claim:
A ring laser gyroscope comprising: an active cavity containing a gain medium; a first plurality of reflective surfaces coupled to the active cavity, the first plurality of reflective surfaces including at least a first reflective surface, a second reflective surface, and a third reflective surface, wherein the first reflective surface, the second reflective surface, and the third reflective surface of the first plurality of reflective surfaces are positioned to reflect light along a path defined in the active cavity between the first plurality of reflective surfaces; at least one medium exciter operable to excite the gain medium, wherein the excited gain medium induces first and second laser fields within the active cavity, wherein the first laser field travels in a clockwise direction within the active cavity and the second laser field travels in a counter-clockwise direction within the active cavity; a first passive cavity coupled to the active cavity through the first reflective surface, wherein the first passive cavity is devoid of gain media; a second plurality of reflective surfaces coupled to the first passive cavity, the second plurality of reflective surfaces including at least the first reflective surface, a fourth reflective surface, and a fifth reflective surface, wherein the first reflective surface, the fourth reflective surface, and the fifth reflective surface of the second plurality of reflective surfaces are positioned to reflect light along a path defined in the first passive cavity between the second plurality of reflective surfaces; a second passive cavity coupled to the first passive cavity through the fourth reflective surface, wherein the second passive cavity is devoid of gain media; a third plurality of reflective surfaces coupled to the second passive cavity, the third plurality of reflective surfaces include at least the fourth reflective surface, a sixth reflective surface, and a seventh reflective surface, wherein the fourth reflective surface, the sixth reflective surface, and the seventh reflective surface of the third plurality of reflective surfaces are positioned to reflect light along a path defined in the second passive cavity between the third plurality of reflective surfaces; wherein the first reflective surface and the fourth reflective surface are partially transmissive such that a first portion of light incident on the first reflective surface is reflected, a second portion of light incident on the first reflected surface is transmitted, a third portion of light incident on the fourth reflective surface is reflected, and a fourth portion of light incident on the fourth reflective surface is transmitted; and wherein at least one of the second and third cavities induce a frequency dependent phase shift on light traveling through the ring laser gyroscope causing anomalous dispersion of the first and second laser fields passing through the gain medium.