Compact, integral, 6-mirror, triaxial, laser rate gyro

Abstract

A triaxial ring laser gyroscope with three square optical paths which are planar and orthogonal with respect to one another, this laser gyroscope comprising six optical mirrors interconnected two by two by means of twelve optical path segments (capillary channels), said segments forming an octahedron, with one mirror for each corner, each of the mirrors operating simultaneously in two orthogonal optical paths.

We claim: 
     
       1. A triaxial laser gyroscope having three sensing axes and being adapted to produce simultaneously distinct measurements of angular movement around each of said axes, comprising: (a) a solid body;   (b) three square-shaped optical paths formed in said body and arranged mutually orthogonally with respect to each other, the geometrical axis of each of the square shapes defined by said paths corresponding to respective ones of said sensing axes; each of said paths comprising four coplanar, linearly extending capillaries arranged to form said square shapes, said paths being situated such that any two opposite corners of one square path coincide with two opposite corners of one of the other square paths, whereby said capillaries are arranged to form an octahedron having six apexes, each of said apexes corresponding to one of said respective sets of two coinciding corners; and   (c) six optical mirrors located respectively at said six apexes, each of said mirrors intersecting the four respective capillaries forming the respective apex, and each of said mirrors being effective in two of said optical paths.   
     
     
       2. A triaxial laser gyroscope according to claim 1, wherein three of said six mirrors are provided with a mixing prism. 
     
     
       3. A triaxial laser gyroscope according to claim 2, in which the thickness of said mixing prism is adapted to permit simultaneous passage of the beam circulating in a first one of said optical paths by reflection and passage of the beam circulating in a second one of said optical paths by reflection, said second path being orthogonal to said first optical path. 
     
     
       4. A triaxial laser gyroscope according to claim 1, wherein three of said mirrors are provided with a mixing prism and the three remaining mirrors are each provided with a mechanical device adapted to displace said mirror along its axis parallel to itself. 
     
     
       5. A triaxial laser gyroscope according to claim 1, wherein said optical path segments define a regular octahedron and each optical path is a square. 
     
     
       6. A triaxial laser gyroscope according to claim 1, further comprising an amplifier device having three anodes and one cathode, which one anode being provided per optical path, and having a cathode common to the three optical paths. 
     
     
       7. A triaxial laser gyroscope according to claim 1, wherein each of said optical path segments comprises a capillary. .Iadd. 
     
     
       8.  A triaxial laser gyroscope according to claim 1 further comprising a plasma amplifier device using at least one electrode of a first type which is common to said paths and communicates with capillaries contained in one first side of the octahedron; and three electrodes of a second type which communicate respectively with capillaries contained in a second side of the octahedron opposite to the first side, one of said electrodes being an anodic type and the other electrode being a cathodic type. .Iaddend. .Iadd.9. A triaxial laser gyroscope according to claim 8, wherein each of said electrodes communicates with at least a corresponding capillary in a point which separates said corresponding capillary in two unequal parts. .Iaddend. .Iadd.10. A ring laser gyroscope having at least two sensitive axes and at least first and second cavities forming respective optical paths, said first and second cavities each having a plurality of corners arranged so that at least one corner of the first cavity coincides with a corner of the second cavity, so as a to form coinciding corners, the gyroscope further comprising a common mirror disposed at the coinciding corners so as to function in the first and second cavities, and a plurality of mirrors disposed respectively at the remaining corners of the 
     
     
        first and second cavities. .Iaddend. .Iadd.11.  A ring laser gyroscope according to claim 10 wherein said cavities are formed in a single solid body made of an electrical insulating material. .Iaddend. .Iadd.12. A ring laser gyroscope according to claim 10 which further comprises for each of said cavities a plasma amplifier device using a cathode electrode and an anode electrode, wherein one of said electrodes is common to the first and to the second cavities. .Iaddend. .Iadd.13. A three-axis ring laser gyroscope comprising three cavities each having four corners, said cavities being arranged in mutually orthogonal planes, at right angles to each respective axis, each corner of one cavity coinciding with one corner of another cavity and six mirrors disposed respectively at the coinciding corners and oriented with respect to said cavities so that each mirror which is disposed at the coinciding corners of two corresponding cavities functions in said two corresponding cavities. .Iaddend. .Iadd.14. A three-axis ring laser gyroscope according to claim 13 wherein said cavities are formed in a single solid body made of an electrical insulating material. .Iaddend..Iadd.15. A three-axis ring laser gyroscope according to claim 13 which further comprises for each of said cavities a plasma amplifier device using two electrodes, a cathode electrode and an anode electrode, wherein one of said electrodes is common to the three cavities. .Iaddend. .Iadd.16. A three-axis ring laser gyroscope according to claim 13 wherein each of said cavities forms a four sided optical path. .Iaddend. .Iadd.17. A three-axis gyro assembly having three sensing axes and comprising: a body;   three mobile mirrors and at least three fixed mirrors provided on the body;   three optical paths formed in the body and respectively disposed in three planes lying respectively at right angles to the said axes, each of said optical paths having two corners respectively provided with two of said movable mirrors and two of said fixed mirrors;   means for generating laser beams in the three optical paths, said laser beams having respective output powers;   three photoelectric detectors located so as to deliver respectively data representative of said powers;   said movable mirrors having positions which vary as a function of said data so as to regulate the length of said optical paths, wherein data delivered from one of said detectors causes a first displacement of one of said movable mirrors and an opposite displacement of the two other movable mirrors.