Patent ID: 9733084
Date: 2017-08-15
CPC Classifications: G01C

Claim:
1. A ring laser gyroscope comprising: an optical ring resonator configured to propagate optical beams in a first direction and a second direction, the second direction being opposite the first direction, the optical ring resonator including at least one optical coupling region to couple optical beams into and out of the optical ring resonator; and an optical source to provide a pump beam at a pump frequency, the pump beam being optically coupled to the optical ring resonator in the first direction; wherein the pump beam stimulates a first optical gain curve at a first stokes wave frequency downshifted by a Brillouin stokes frequency from the pump frequency, wherein the optical ring resonator has a resonator mode within a bandwidth of the first optical gain curve, wherein the resonator round-trip loss is less than the first optical gain, so that a first order stimulated Brillouin scattering (SBS) beam propagates in the second direction, wherein the first order SBS beam stimulates a second optical gain curve at a second stokes wave frequency downshifted by twice the Brillouin Stokes frequency from the pump frequency, wherein the optical ring resonator has a resonator mode within the bandwidth of the second optical gain curve, wherein the resonator round-trip loss is less than a second optical gain, so that a second order SBS beam propagates in the first direction; and the ring laser gyroscope further comprising: a beat detector configured to produce an optical beat signal that varies as a function of a frequency difference between the first order SBS beam and the second order SBS beam; and an optical clock detector to generate a reference frequency signal based on two co-propagating beams.