US 7,561,275 B2
	Scale-factor stabilized solid-state laser gyroscope
Gilles Feugnet, Les Ulis (France); Sylvain Schwartz, Paris (France); Jean-Paul Pocholle, La Norville (France); Christian Larat, Paris (France); and Francois Gutty, Chatellerault (France)
Assigned to Thales, (France)
Appl. No. 11/576,838 PCT Filed Oct. 06, 2005, PCT No. PCT/EP2005/055035 § 371(c)(1), (2), (4) Date Apr. 06, 2007, PCT Pub. No. WO2006/037795, PCT Pub. Date Apr. 13, 2006.
Claims priority of application No. 04 10659 (FR), filed on Oct. 08, 2004.
Prior Publication US 2008/0037026 A1, Feb. 14, 2008
Int. Cl. G01C 19/66 (2006.01)

U.S. Cl. 356—459

9 Claims

1. A laser gyro, comprising: a ring cavity of optical length L and of area A, and a solid-state amplifying medium wherein two optical waves of average wavelength λ propagate in opposite directions inside the cavity, the scale factor S of the laser gyro being equal to wherein the cavity has a geometric perimeter Lo, said cavity comprising at least one optical element Oi traversed by the optical waves, i being an integer index varying between 1 and the total number of optical elements, the optical element Oi having length Li, optical index ni, xi being equal to the ratio being the coefficient of variation as a function of temperature T of the optical index ni of the optical element Oi, αi being the linear expansion coefficient of the optical element Oi, α0 being the linear expansion coefficient of the constituent material of the cavity, v being the central emission frequency of the amplifying medium and being the coefficient of variation as a function of temperature T of said frequency, said optical elements and the amplifying medium are designed so that the following relation is substantially satisfied: