Laser rotation rate sensor

Claim 2

A laser rotation rate sensor wherein two light beams counterrotate in a polygon equipped with reflectors in its corners, a signal being derived from their frequency difference which depends on the rate of rotation, said rotation rate sensor comprising a reflector having a magneto-optic element for the suppression of lock-in and including a prism whose base boundary face is disposed adjacent a layer of a gyrotropic material, characterized in that the index of refraction of the gyrotropic material is approximately equal to or greater than that of the prism; a further layer of a dielectric material is disposed adjacent the gyrotropic layer, said further layer having a smaller index of refraction than that of the prism material and that of the material of the gyrotropic layer, in such a manner that total reflection occurs at the interface between the layer of gyrotropic material and the further layer.

Claim 3

A laser rotation rate sensor according to claim 1, characterized in that, due to adherence to the Brewster condition, almost no reflection occurs when light enters at its two lateral faces.

Claim 4

A laser rotation rate sensor according to claim 1 or 2, characterized in that the further layer is the ambient air or a vacuum environment.

Claim 5

A laser rotation rate sensor, comprising: an optical amplifier having first and second opposite ends for emitting first and second beams of light, said first and second beams of light travelling in opposite directions around a closed optical path; an optical detector; a magneto-optic reflector positioned in the path of said first laser beam, said reflector including a coupling prism having an index of refraction n 1 , said coupling prism having at least first and second surfaces with an angle β therebetween; a gyrotropic layer having first and second opposing surfaces, said first surface being affixed to the second surface of said coupling prism, the index of refraction n 2 of said gyrotropic layer being equal to or greater than n 1 ; and a single dielectric layer having a surface affixed to the second surface of said gyrotropic layer, the index of refraction n 3 of said dieletric layer being less than n 1 or n 2 , said first laser beam inpinging at the Brewster angle on the first surface of said coupling prism, being totally reflected at the interface between said gyrotropic layer and said dielectric layer and being emitted as a single output beam from said reflector, and optical means transmitting the output beam from said reflector and said second laser beam to said optical detector, the output of said optical detector corresponding to the difference in frequency between said first and second beams of light.

Claim 6

A laser rotation rate sensor, comprising: an optical amplifier having first and second opposite ends for emitting first and second beams of light, said first and second beams of light travelling in opposite directions around a closed optical path; an optical detector; a magneto-optic reflector positioned in the path of said first laser beam, said reflector including a coupling prism having an index of refraction n 1 , said coupling prism having at least first and second surfaces with an angle β therebetween; a gyrotropic layer having first and second opposing surfaces, said first surface being affixed to the second surface of said coupling prism, the index of refraction n 2 of said gyrotropic layer being equal to or greater than n 1 ; and a single dielectric layer having a surface affixed to the second surface of said gyrotropic layer, the index of refraction n 3 of said dieletric layer being less than n 1 or n 2 , said first laser beam inpinging at the Brewster angle on the first surface of said coupling prism, being totally reflected at the interface between said gyrotropic layer and said dielectric layer and being emitted as a single output beam from said reflector, and optical means transmitting the output beam from said reflector and said second laser beam to said optical detector, the output of said optical detector corresponding to the difference in frequency between said first and second beams of light.