Abstract: A system that includes a high performance sensor to provide accurate measurements and at least one dissimilar sensor that is less accurate. The at least one dissimilar sensor is of a different type of sensor than the high performance sensor while providing a same type of measurement as the high performance sensor. The at least one dissimilar sensor has a longer life expectancy than the high performance sensor. An at least one controller is configured to start both the high performance sensor and the at least one dissimilar sensor at startup of the system, to turn off the high performance sensor after a select period of time, and to output measurement data based on measurements of the high performance sensor while the high performance sensor is on and output the measurement data based on the at least one dissimilar sensor when the high performance sensor is off.

Abstract: A system that includes a high performance sensor to provide accurate measurements and at least one dissimilar sensor that is less accurate. The at least one dissimilar sensor is of a different type of sensor than the high performance sensor while providing a same type of measurement as the high performance sensor. The at least one dissimilar sensor has a longer life expectancy than the high performance sensor. An at least one controller is configured to start both the high performance sensor and the at least one dissimilar sensor at startup of the system, to turn off the high performance sensor after a select period of time, and to output measurement data based on measurements of the high performance sensor while the high performance sensor is on and output the measurement data based on the at least one dissimilar sensor when the high performance sensor is off.

Abstract: A ring laser gyroscope is provided. A light source is configured to generate light of a first wavelength. A plurality primary cavity mirrors are configured to route light of a second wavelength around a primary cavity to a readout device. One primary cavity mirror of the plurality of primary cavity mirrors includes a gain medium. The pumping mirror and the one primary cavity mirror including the gain medium is positioned and configured to reflect the light of the first wavelength back and forth in a pumping cavity through the gain medium, wherein the light of the first wavelength stimulates the gain medium to generate the light of the second wavelength that are reflected around the primary cavity to the readout device.

Abstract: A ring laser gyroscope comprises an optical block that defines an optical closed loop pathway; at least one mirror structure mounted on the optical block and in communication with the closed loop pathway; at least one volume Bragg grating mounted on the optical block and in communication with the closed loop pathway; and a pump laser in communication with the volume Bragg grating, the laser operative to emit a light beam at a selected incident angle such that the beam passes through the volume Bragg grating and overlaps with the closed loop pathway. The volume Bragg grating is operative as a gain medium to increase an optical power of the beam, and a pair of counter-propagating beams is produced within the closed loop pathway from the beam. The mirror structure and the volume Bragg grating are positioned and angled to reflect the counter-propagating beams around the closed loop pathway.

Abstract: A ring laser gyroscope is provided. A light source is configured to generate light of a first wavelength. A plurality primary cavity mirrors are configured to route light of a second wavelength around a primary cavity to a readout device. One primary cavity mirror of the plurality of primary cavity mirrors includes a gain medium. The pumping mirror and the one primary cavity mirror including the gain medium is positioned and configured to reflect the light of the first wavelength back and forth in a pumping cavity through the gain medium, wherein the light of the first wavelength stimulates the gain medium to generate the light of the second wavelength that are reflected around the primary cavity to the readout device.

Abstract: A solid state ring laser gyroscope comprises a laser block including a resonant ring cavity having an optical closed loop pathway; a plurality of mirror structures mounted on the block and including respective multilayer mirrors that reflect light beams around the closed loop pathway; and a pump laser assembly in optical communication with the closed loop pathway through one of the mirror structures. One or more of the multilayer mirrors includes a rare-earth doped gain layer operative to produce bidirectional optical amplification of counter-propagating light beams in the closed loop pathway. In some embodiments, the gain layer comprises a rare-earth dopant other than neodymium that is doped into a glassy host material comprising titania, tantalum oxide, alumina, zirconia, silicate glass, phosphate glass, tellurite glass, fluorosilicate glass, or non-oxide glass. Alternatively, the gain layer can comprise a neodymium dopant that is doped into a glassy host material other than silica.

Abstract: Systems and methods for end pumped laser mirror stack assemblies are provided. In one embodiment, an end pump mirror stack assembly for a laser resonator comprises: a pump light injection layer applied to a transparent substrate, the pump light injection layer comprising at least one light generating optical emitter embedded within the pump light injection layer, wherein the pump light injection layer is configured to transmit a pump light having a first wavelength into the substrate; a multilayer thin-film mirror stack coupled to the transparent substrate; a lasing material layer coupled transparent substrate and positioned to receive the pump light, wherein the lasing material layer is doped with a dopant that generates a fluorescent light output at a second frequency when exposed to the pump light; and an antireflective coating applied to the substrate, the first anti-reflective coating configured to pass light of the first wavelength.

Abstract: A solid state ring laser gyroscope comprises a laser block including a resonant ring cavity having an optical closed loop pathway; a plurality of mirror structures mounted on the block and including respective multilayer mirrors that reflect light beams around the closed loop pathway; and a pump laser assembly in optical communication with the closed loop pathway through one of the mirror structures. One or more of the multilayer mirrors includes a rare-earth doped gain layer operative to produce bidirectional optical amplification of counter-propagating light beams in the closed loop pathway. In some embodiments, the gain layer comprises a rare-earth dopant other than neodymium that is doped into a glassy host material comprising titania, tantalum oxide, alumina, zirconia, silicate glass, phosphate glass, tellurite glass, fluorosilicate glass, or non-oxide glass. Alternatively, the gain layer can comprise a neodymium dopant that is doped into a glassy host material other than silica.

Abstract: A multilayer mirror, ring laser gyroscope and method are disclosed. For example, the multilayer mirror includes a plurality of alternating layers of a high index of refraction optical material and a low index of refraction optical material, an amplification layer of an optical material disposed on the plurality of alternating layers, and a coating of an anti-reflective material disposed on an outermost surface of the optical material amplification layer.

Abstract: Systems and methods for predictive health monitoring of gyroscopes and accelerometers are provided. In one embodiment, a system comprises: a plurality of navigation devices each comprising at least one gyroscope or accelerometer and at least one predictive health monitoring module, wherein the at least one predictive health monitoring module collects diagnostic parameters from the at least one gyroscope or accelerometer; and at least one server communicatively coupled to the plurality of navigation devices, the at least one server configured to receive the collected data from the plurality of navigation devices and analyze the collected data from the plurality of navigation devices to determine a service prognosis.

Abstract: Systems and methods for dynamic PLC modulation are provided. In certain embodiments, a gyroscope system includes a block having cavities and passages that define a path; mirrors, each located in one of the cavities, direct light along the path defined by the cavities and the passages; a mirror drive coupled to one of the mirrors to change a position of the mirror, wherein the path's length is changed as the mirror's position changes; a photodetector that measures power of light along the path; and a controller that provides a control signal indicative of an amplitude of PLC modulation and a PLC frequency to the mirror drive; wherein the mirror drive, in response to the control signal, changes the position of the mirror at the frequency, wherein the mirror drive moves based on the amplitude; and wherein the controller changes the amplitude in relation to the measured power of the light.

Abstract: Systems and methods for dynamic PLC modulation are provided. In certain embodiments, a gyroscope system includes a block having cavities and passages that define a path; mirrors, each located in one of the cavities, direct light along the path defined by the cavities and the passages; a mirror drive coupled to one of the mirrors to change a position of the mirror, wherein the path's length is changed as the mirror's position changes; a photodetector that measures power of light along the path; and a controller that provides a control signal indicative of an amplitude of PLC modulation and a PLC frequency to the mirror drive; wherein the mirror drive, in response to the control signal, changes the position of the mirror at the frequency, wherein the mirror drive moves based on the amplitude; and wherein the controller changes the amplitude in relation to the measured power of the light.

Abstract: Systems and methods for predictive health monitoring of gyroscopes and accelerometers are provided. In one embodiment, a system comprises: a plurality of navigation devices each comprising at least one gyroscope or accelerometer and at least one predictive health monitoring module, wherein the at least one predictive health monitoring module collects diagnostic parameters from the at least one gyroscope or accelerometer; and at least one server communicatively coupled to the plurality of navigation devices, the at least one server configured to receive the collected data from the plurality of navigation devices and analyze the collected data from the plurality of navigation devices to determine a service prognosis.

Abstract: A ring laser gyroscope configured to reduce alignment shifts in at least one critical alignment of the ring laser gyroscope is provided. The ring laser gyroscope includes reflective components configured to direct clockwise optical beams and counter-clockwise optical beams in at least one lasing plane; at least one ring-laser-gyro mounting feature having at least one respective through hole; and at least one minimally-threaded screw positioned in the at least one respective through hole. An unthreaded section of the minimally-threaded screw is contactlessly encased in the at least one respective through hole. A threaded-end of the at least one minimally-threaded screw is threaded in a respective at least one threaded hole in a gyro frame, the gyro frame spanning a reference mounting plane.

Abstract: A method and system for rate sensitive blanking in a path length control circuit of a gyroscope is provided. The method comprises determining an angular rate of the gyroscope, detecting a zero rate of the gyroscope where one or more single beam signals occur, and determining one or more blanker positions based on the zero rate. A blanker pulse is generated at the blanker positions such that the path length control circuit suspends operation when the one or more single beam signals occur.

Abstract: Systems and methods for thermal gradient compensation for ring laser gyroscopes are provided. In one embodiment, a method for producing bias compensated angular rate measurements from a ring laser gyroscope comprises: sampling an angle measurement output from a laser block sensor to obtain an angular rate measurement; obtaining an laser block temperature measurement (Tblock) for the laser block sensor; obtaining a temperature gradient measurement (Tdiff) for at least one gradient line across a portion of the laser block sensor; calculating a rate bias error by applying parameters produced from the temperature measurement (Tblock) and the temperature gradient measurement (Tdiff) to a thermal gradient compensation model, wherein the thermal gradient compensation model includes at least one coefficient corresponding to the temperature gradient measurement (Tdiff); and calculating a difference between the angle rate measurement and the rate bias error to produce a bias compensated angular rate measurement.

Abstract: A vacuum chamber assembly includes a vacuum chamber containing a reactive material, an inlet fill tube fixedly attached to the vacuum chamber, and an outlet fill tube fixedly attached to the vacuum chamber. The inlet fill tube has a first vacuum tight seal and the outlet fill tube has a second vacuum tight seal.

Abstract: Systems and methods for thermal gradient compensation for ring laser gyroscopes are provided. In one embodiment, a method for producing bias compensated angular rate measurements from a ring laser gyroscope comprises: sampling an angle measurement output from a laser block sensor to obtain an angular rate measurement; obtaining an laser block temperature measurement (Tblock) for the laser block sensor; obtaining a temperature gradient measurement (Tdiff) for at least one gradient line across a portion of the laser block sensor; calculating a rate bias error by applying parameters produced from the temperature measurement (Tblock) and the temperature gradient measurement (Tdiff) to a thermal gradient compensation model, wherein the thermal gradient compensation model includes at least one coefficient corresponding to the temperature gradient measurement (Tdiff); and calculating a difference between the angle rate measurement and the rate bias error to produce a bias compensated angular rate measurement.

Abstract: A method and system for rate sensitive blanking in a path length control circuit of a gyroscope is provided. The method comprises determining an angular rate of the gyroscope, detecting a zero rate of the gyroscope where one or more single beam signals occur, and determining one or more blanker positions based on the zero rate. A blanker pulse is generated at the blanker positions such that the path length control circuit suspends operation when the one or more single beam signals occur.

Abstract: A vacuum chamber assembly includes a vacuum chamber containing a reactive material, an inlet fill tube fixedly attached to the vacuum chamber, and an outlet fill tube fixedly attached to the vacuum chamber. The inlet fill tube has a first vacuum tight seal and the outlet fill tube has a second vacuum tight seal.