Abstract: An optical fiber coil assembly includes an optical fiber wound about an axis of rotation. A first section of the fiber, from the intermediate point to the first end, is wound around a bobbin in a first direction about the axis of rotation. A second section of the fiber, from the intermediate point to the second end, is wound, at least partially, around the bobbin in a second direction opposite the first direction. A reversal of the fiber, however, allows an end portion of the second section to be wound around the bobbin in the first direction, along with an end portion of the first section. The coil assembly further includes an epoxy zipper disposed between the first and second sections of the fiber, forming a fiber lead pair. An epoxy bridge disposed between the fiber lead pair and the bobbin secures the fiber lead pair to the bobbin.

Abstract: A system and method for providing a rotation sensor for use in a fiber optic gyroscope including a centrally-located cylindrical hub having an improved slip interface positioned there around. The central hub has a substantially planar mounting flange extending from one of its ends, where the axis of rotation of the central hub is orthogonal to the plane of the mounting flange. A sensor coil comprising a plurality of layers of coaxial turns of optical fiber embedded in a potting material is formed around an outer surface of the interface. The interface allows the potted coil to expand or contract along the axial direction of the central hub due to thermal expansion while maintaining a constant thermal and mechanical connection between the interface and the potted coil. In this manner, the present invention maintains the integrity of the potted coil and its connection to the interface during thermal expansion of the potted coil, thus minimizing temperature-induced Shupe bias errors in the rotation sensor.

Abstract: An optical fiber coil assembly includes an optical fiber wound about an axis of rotation. A first section of the fiber, from the intermediate point to the first end, is wound around a bobbin in a first direction about the axis of rotation. A second section of the fiber, from the intermediate point to the second end, is wound, at least partially, around the bobbin in a second direction opposite the first direction. A reversal of the fiber, however, allows an end portion of the second section to be wound around the bobbin in the first direction, along with an end portion of the first section. The coil assembly further includes an epoxy zipper disposed between the first and second sections of the fiber, forming a fiber lead pair. An epoxy bridge disposed between the fiber lead pair and the bobbin secures the fiber lead pair to the bobbin.

Abstract: Interconnection mechanisms for a laser gyroscope assembly (10) enable it to be rapidly and non-harmfully assembled and disassembled prior to a more durable interconnection, to facilitate repair and rework. The assembly includes a fiber optic spool (12), an inner shield (16) and an outer shield (18), which are formed of a stress-annealed magnetic and generally malleable material. The outer shield comprises upper and lower portions or parts (30, 32) whose first and second end segments (62, 66) respectively terminate the portions. Segment (66) has angled intersecting conical surfaces (74, 76) which engage surfaces (65, 67) on segment (62). Stops (80, 83) are formed respectively on the ends of the segments so that a distal end (68) contacts an interior ledge surface (80) of outer shield (34), thereby to limit the mutual engagement and to center the segment configuration interfit.

Abstract: An hermetically sealed fiber optic gyroscope assembly has loops of optic fiber on a support ring in a sealed casing comprising a base plate, a perimeter wall upstanding from the base plate and a cover secured to the perimeter of the wall, together with optical circuitry located within the casing for directing light around the optic fibre loops together with electrical connecting circuitry passing from the optical circuitry to external terminals in sealed engagement with the casing.

Abstract: The invention relates to the field of fiber optics, and more particularly to birefringence in single-mode fibers. The sensitivity of a fiber optic sensor coil for a current sensor may be increased by winding the sensing fiber, without torsion, around a current-carrying wire to form the coil, wherein the pitch angle of the fiber may be selected to result in a phase shift due to Berry's phase of circularly polarized light propagating through the fiber. Preferably, the pitch angle may be approximately 60°.

Abstract: An integrated optic gyro has a multi-level optical coil having a mounting plate, a top substrate, and a bottom substrate, the top substrate being bonded to the mounting plate, the bottom substrate being bonded to the mounting plate. The top substrate has a top waveguide coil The bottom substrate has a bottom waveguide coil. A coupler has an input port, a first, second and third output port. A first optical fiber couples the top waveguide coil to the bottom waveguide coil. The coils are coupled to have a common rotational sense. A second optical fiber connects the coupler's first output port to the top waveguide coil. A third optical fiber for connects the coupler's second output port to the bottom waveguide coil. A light source couples a light wave into the coupler's first input port. The coupler splits the light wave into substantially equal first and second output waves.

Abstract: A fiber optic coil has a plurality of layers of turns. The turns of a first layer of the plurality of layers of turns are adjacent and are wound from an optical fiber having a first diameter. The turns of other layers of the plurality of layers turns are found from an optical fiber having a second diameter. The second diameter is less than the first diameter. The first layer may or may not be part of a sensing path provided by the plurality of layers of turns.

Abstract: A rectification error reducer for a fiber optic gyroscope, which is an intensity servo or compensator for reducing vibration effects in the optical signals caused by modulation at vibration frequencies induced by the gyroscope-operating environment. The vibration effects may be detected in signals from the photodiode output in amplitude form, which is used in a control system to null out optical intensity variations at the frequencies of vibration.

Abstract: An interferometric sensor having an optic fiber which forms a sensing loop optical path and a second loop that is wound in the opposite direction of the sensor loop. Circularly polarized light propagates along the optical path of the sensing loop. A differential phase shift is induced in the light waves by a magnetic field of the current in a conductor. The light waves with their phase relationship are detected by a photo detector which outputs an electrical signal that is processed by loop closure electronics into a signal indicative of the current's magnitude and direction. If the phase shift due to rotation is sensed in the sensing loop, then that phase shift is canceled by an opposite phase shift from the compensating loop. The compensating loop or coil may be reversed in connections, or flipped over, for calibrating the current sensor.

Abstract: A gyroscope which utilizes light waves to sense motion in the plane of the substrate. The gyroscope has a primary optical waveguide which is adapted to pass light from a single light source through the primary optical waveguide in both directions. The light exiting from each end of the primary optical waveguide is withdrawn and passed through two dedicated waveguides (one dedicated waveguide for each end of the primary optical waveguide). Preferably, these two dedicated waveguides have differing times for light travel such that one of the dedicated waveguides emits its light one-quarter wavelength behind the other dedicated waveguide. The light being emitted from each dedicated waveguide is then combined permitting a sensor to monitor any shifts between the two light signals as a monitor to motion of the primary optical waveguide.

Abstract: A gyroscope comprising a source for emitting a light beam, an optical fiber loop in which the light propagates in both directions, a dual phase-conjugate mirror disposed in said loop in such a manner that light reaches said mirror from both sides thereof, recombination means for recombining the light which has propagated round the loop, and detector means for detecting the recombined signal, wherein the loop includes a monomode fiber that does not conserve polarization and wherein depolarization means are disposed between said fiber and the phase-conjugate mirror, on either side thereof.

Abstract: A design for an environmentally robust fiber depolarizer for a fiber optic gyroscope is disclosed. The design comprises; substantially a clockwise propagating leg and a counterclockwise propagating leg, distally coupled at opposite ends of a gyroscope sensing coil, said depolarizer fiber leg wound in a that is rotation insensitive pattern and that is also a symmetrical winding pattern. Moreover, axial, radial and embedded sensing coil mounting methods for the fiber depolarizer to reduce the depolarizer sensitivity to thermal variations are also disclosed. Specific attention to the design of the fiber depolarizer of a gyroscope provides enhanced immunity to the stress of environmental variation.