Abstract: A solid state silicon micromachined acceleration and Coriolis (MAC) sensor that measures linear and angular motion. The MAC sensor is a single device that performs the functions of a conventional accelerometer and a gyroscope simultaneously. The MAC sensor is unique in that it is a differential dual stage device using only one micromachined proof mass to measure both linear and angular motions. The single proof mass is connected to opposing electromechanical resonators in a monolithic microstructure made from single crystal silicon. This unique design offers improvements in measurement performance and reductions in fabrication complexity that are beyond the state the art of earlier micromachined inertial sensors.

Abstract: A solid state silicon micromachined acceleration and Coriolis (MAC) sensor that measures linear and angular motion. The MAC sensor is a single device that performs the functions of a conventional accelerometer and a gyroscope simultaneously. The MAC sensor is unique in that it is a differential dual stage device using only one micromachined proof mass to measure both linear and angular motions. The single proof mass is connected to opposing electromechanical resonators in a monolithic microstructure made from single crystal silicon. This unique design offers improvements in measurement performance and reductions in fabrication complexity that are beyond the state the art of earlier micromachined inertial sensors.

Abstract: A gyroscope for detecting angular velocity includes a closed housing having a plurality of nested layers of superconducting material with the majority of these nested layers being divided so as to disrupt the path of superelectrons traveling within the superconducting material of these nested layers. These nested layers of superconducting material shield the interior of the closed housing from external magnetic fields and prevent the generation of a London moment field within the closed housing when the housing is rotated. A gyroscope sensor is securely mounted within the closed housing for detecting the rotation of the housing. The gyroscope sensor is comprised of a gyroscope sensor block having a plurality of sensor device faces where a corresponding plurality of gyroscope sensor devices are situated. Each of the plurality of gyroscope sensor devices is comprised of a multilayer superconducting thin film structure.

Abstract: A quantum well bias mirror 30 provides phase modulation to two counter-propagating beams in a ring laser gyroscope so as to reduce or eliminate the effects of lock-in. The phase modulation is caused by inducing an index of refraction change, known as the Franz-Keldysh effect, in the quantum well bias mirror 30 by applying a varying electric field across a quantum well structure in the mirror 30. The quantum well bias mirror 30 is comprised of a substrate 32 coated with a plurality of dielectric layers 36,38 of alternately high and low refractive indices, respectively, which in turn are coated with a quantum well filter layer 34. The dielectric layers 36,38 are adjusted to provide maximum reflectivity of the counter-propagating beams. The quantum well filter layer 34 is adjusted to cause a reflection from its top surface when there is no electric field present and to cause a reflection from the top of the dielectric layers 36,38 when an electric field is present.

Abstract: A ring laser gyro system having at least one fixed mirror, and two movable mirror assemblies, for causing a pair of laser beams to counter-rotate therebetween, including amplitude control circuits and a phase control circuit for causing the movable mirror assemblies to sinusoidally oscillate at the same amplitude and frequency, but 180.degree. out of a phase with one-another, to substantially eliminate lock-in.

Abstract: A piezoelectric actuator for use in controlling the path length, for example, in a ring laser gyro is made of two piezoelectric discs attached to a metallic structure for exerting a push-pull force thereon to move the metallic structure in an oil can fashion. The piezoelectric actuator is attached to a dual diaphragm mirror assembly in such a way as to impart a strictly linear motion to the mirror assembly without any deliterious rotational effects. The actuator can easily be optimized for varying diaphragm stiffness by adjusting the thickness of the metallic structure to which the piezoelectric discs are attached. The mirror assembly and actuator are designed to minimize the influence of temperature changes on the position of the path length mirror.

Abstract: In a monolithic gyro assembly having three ring laser gyroscopes each measuring the inertial rotation of an axis, a polyhedron having three facets is used as the beam combiner for the gyroscope. On one of the facets is mounted a fringe detector for providing inertial rotation information for the gyroscope. On the remaining two facets, on either side of the fringe detector facet, are mounted beam power monitoring diodes for measuring the power of the light intensity of the respective beams. The directly measured power from the beams is then used to move a piezoelectric transducer to maintain constant pathlengths for the gyroscope.

Abstract: Instead of using two power monitoring photodiodes and associated summing circuitries for adding the power of the laser beams circulating in the cavity of a ring laser gyro, the present invention eliminates one of the photodiodes and uses, in its stead, reflective means for directing both of the laser beams onto the remaining power monitoring photodiode, which automatically measures and sums the light intensities or power from the laser beams and provides as an output the thus added power directly to the necessary electronic circuitry to maintain constant the pathlength of the cavity.

Abstract: A beam combiner assembly for a ring laser gyroscope is fabricated by positioning two diffraction gratings, mounted onto respective light transmissive substrates, with respect to the output mirror of the gyro block at an offset angle such that an interference fringe pattern is projected onto the photodetector of the ring laser gyroscope. By tilting the diffraction gratings, with respect to the plane of the output mirror, a corrected number of lines per unit length for the diffraction gratings may be effected, thereby providing a beam combiner assembly which is compensated for manufacturing imperfections and other intolerances. Also, the high sensitivity of angular adjustments for the conventional prism beam combiner is overcome.

Abstract: In a precision ring laser gyroscope, to eliminate the effect of an unwanted and unintentional moment generated as a result of a force being applied onto a pathlength controller, a pathlength control assembly is constructed to have optimal hub and diaphragm portions such that the mirror element mounted thereto does not tilt in response to the unintentional moment.

Abstract: A piezoelectric activated dither suspension system for a ring laser gyroscope has all of the transducer elements connected in parallel to simultaneously produce sustaining torque for dither motion and respond to a back component of current produced by the vibrational motion of the gyro block. The generated current, separated from drive currents from the torquer amplifier by a transformer or, in an alternative embodiment, by sensing resistors, produces the very signal used to control and sustain the oscillations. By utilizing all transducers both as torquer and pickoff elements, economies of drive efficiency, wiring simplification and circuit redundancies are achieved.