Ring laser gyro and magnetic mirror therefor

Magnetic mirror comprising:

• a substrate;
• conductors disposed in said substrate for generating rapidly switchable magnetic fields;
• a magnetically saturable layer having a well defined easy axis of magnetization disposed on the substrate;
• a magneto-optic layer disposed directly on the magnetically saturable layer;
• and
• a multilayer dielectric stack over the magneto-optic layer.

Laser gyro comprising:

• a gyro block including a block of material having bores therein at least partially defining a closed laser beam path lying in a plane;
• means for completing the laser beam path entirely enclosed within said block including a plurality of mirrors, each of which is contacted to the gyro block at he intersection of said bores to form a closed optical cavity therewith and laser beam path entirely enclosed within the block and mirrors and sealed to the block to form a laser gas containment cavity;
• means for generating counter-rotating laser beams within the cavity;
• said path being free of intracavity elements so that the beam travels unimpeded through the bores by reflection from the mirrors;
• said block including means for discriminating against S-polarization with respect to P-polarization without using Brewster angle windows and including an odd number of mirrors and having a perimeter selected to produce a large frequency splitting between S- and P modes whereby S mode lasing is suppressed, and
• one of said mirrors being constructed and arranged to form a magnetic mirror to introduce a non-reciprocal phase shift between counter-propagating light beams while introducing negligible non-reciprocal losses.

In a ring laser gyro with no intracavity elements

• a polygonal block,
• means forming mirror supporting facets formed at the apexes of the polygon,
• means forming a plurality of passages between facets to define a planar path cavity whose length is such that the frequency separation between S and P modes is at least greater than the half width of the laser gain curve for the P mode,
• means forming a plurality of mirrors mounted to said facets one of which is a pathlength control mirror, one of which is a magnetic mirror which utilizes the transverse Kerr magneto-optic effect to achieve a magnetic bias;
• and one of which is a readout mirror.

Laser gyro comprising:

• a gyro block including a block of material having bores therein at least partially defining a closed laser beam path lying in a plane;
• means for completing the laser beam path entirely enclosed within said block including a plurality of mirrors, each of which is contacted to the gyro block at the intersection of said bores to form a closed optical cavity therewith. The laser beam path entirely enclosed within the block and mirrors and sealed to the block to form a laser gas containment cavity;
• means for generating counter-propagating laser beams within the cavity;
• said path being free of intracavity elements so that the beam travels unimpeded through the bores by reflection from the mirors;
• one of said mirrors having high reflectance and including constructive and destructive interference means for discriminating against S-polarization with respect to P-polarization without using Brewster angle windows;
• one of said mirrors being constructed and arranged to form a magnetic mirror to introduce a non-reciprocal phase shift between said counter-propagating light beams while maintaining negligible non-reciprocal losses.

Laser gyro comprising:

• a gyro block including a block of material having bores therein at least partially defining a closed laser beam path lying in a plane;
• means for completing the laser beam path entirely enclosed within said block including a plurality of mirrors, each of which is contacted to the gyro block at the intersection of said bores to form a closed optical cavity therewith and laser beam path entirely enclosed within the block and mirrors and sealed to the block to form a laser gas containment cavity;
• means for generating counter-propagating laser beams within the cavity;
• said path being free of intracavity elements so that the beam travels unimpeded through the bores by reflection from the mirrors;
• one of said mirrors including constructive and destructive interference means for discriminating against S-polarization with respect to P-polarization without using Brewster angle windows;
• one of said mirrors being constructed and arranged to from a magnetic mirror comprising a magnetic, saturable, fast-switching layer and a magneto-optic layer coupled to said magnetic layer to introduce a non-reciprocal phase shift between said counter-propagating light beams while introducing negligible non-reciprocal losses.