Abstract: A plurality of voids are introduced into a polymeric material. One or more stress sensitive components in abutment with a portion of the polymeric material are buffered from one or more stresses through employment of the portion of the polymeric material that comprises one or more voids of the plurality of voids. A movement of the portion of the polymeric material is accommodated through compression of one or more of the one or more voids.

Abstract: In one example, the voids 208 comprise one or more gas (e.g., air) bubbles in the solid material 206. In another example, the voids 208 comprise a structure that preserves a space in the solid material 206. In a further example, the voids 208 comprise hollow elastomeric bubbles, for example, hollow elastomeric microspheres. The hollow elastomeric microspheres comprise microballoons with tin walls that encapsulate a gas to allow for easy compression. For example, the walls of the hollow elastomeric microspheres are strong enough to avoid breakage under pressure, but thin enough to easily compress. In a further example, once cured in the solid material 206, the hollow elastomeric microspheres comprise substantially similar compressibility characteristics as gas bubbles. The voids 208 in one example are added to a resin of the solid material 206 in a substantially uniform distribution. For example, the hollow elastomeric microspheres are stirred into the resin of the solid material 206.

Abstract: A plurality of voids are introduced into a polymeric material. One or more stress sensitive components in abutment with a portion of the polymeric material are buffered from one or more stresses through employment of the portion of the polymeric material that comprises one or more voids of the plurality of voids. A movement of the portion of the polymeric material is accommodated through compression of one or more of the one or more voids.

Abstract: A potting compound for use in the fabrication of fiber optic gyro sensor coils utilizes a silver-filled silicone base to reduce gyro sensitivity to changes in heat rate and thereby improve gyro performance during warm-up and periods of thermal cycling.

Abstract: An Integrated Optics Chip with improved performance when exposed to rapidly changing temperature is disclosed. The optic chip or integrated optic chip or MIOC has a top surface, a +Z face and -Z face. The chip is formed from a crystal having a high electro-optic coefficient such as Lithium Niobate. For the purpose of orienting the components to the optic chip to be described, the +Z crystal axis extends outward from the +Z face. An input waveguide formed in the top surface of the chip and orthogonal to the +Z axis receives an optical signal from an input port, passes the signal via a waveguide network, to an output waveguide coupling the waveguide network to an output port. Metalization is applied to the top face of the optic chip to form at least a first and a second rail. The first and second rails are positioned to very closely straddle a portion of the input waveguide.

Abstract: A system and method for providing scale factor stabilization of a broadband light source used in fiber optic gyroscopes is provided. A primary bandpass filter is positioned in the propagation path of the light emitted by the broadband light source to narrow the spectral width of the optical signal transmitted to the fiber optic gyroscope, which reduces the centroid wavelength shift resulting when the broadband light source is exposed to ionizing radiation and other harsh environmental conditions. The filtered optical signal is then passed through the fiber optic gyroscope, where the filter optical signal is processed to measure the amount of rotation of the fiber optic gyroscope. The scale factor stabilization system further includes the spectral monitor array arranged to perform direct optical wavelength measurements of the filtered optical signal to determine whether a scale factor shift in the optical signal has occurred.

Abstract: The invention is a focusing polarization rotator for use in the resonant mirror system of a ring laser gyroscope. The focusing polarization rotator accomplishes the traditional task of rotating the plane of polarization of a light beam that passes through it and at the same time performs a focusing function on the light rays. In a resonant mirror system, the device acts to constrain the transverse dimensions of light beams that follow the closed light-beam path established by the resonant mirror system thereby obviating the need for one or more curved mirrors that usually perform this function. The focusing polarization rotator is a wedge-shaped lens made from either a magneto-optic transparent material with a magnetic field within the lens or a material having different indices of refraction for left- and right-circularly-polarized light. The wedge shape of the lens greatly improves the bias stability of the RLG in which it is used.

Abstract: A potting compound for use in the fabrication of fiber optic gyro sensor coils utilizes a silver-filled silicone base to reduce gyro sensitivity to changes in heat rate and thereby improve gyro performance during warm-up and periods of thermal cycling.

Abstract: An integrated optics chip with improved performance when exposed to changing temperature is disclosed. The optic chip or integrated optics chip or MIOC has a top surface, a +Z face and -Z face. The integrated optics chip is formed from a crystal substrate having a high electro-optic coefficient such as Lithium Niobate. For the purpose of orienting the components to the optic chip to be described, the +Z crystal axis extends outward from the +Z face, the Z axis being the axis across which a pyroelectric effect is exhibited. The top surface is orthogonal to the Z axis. An input waveguide on the top surface receives an optical signal from an input port, passes the signal via a waveguide network, to an output waveguide coupling the waveguide network to an output port. A portion of the +Z and -Z faces are coated at least partially with a conductive coating.

Abstract: A method and apparatus for reducing the temperature-dependent Shupe bias of a potted gyro sensor coil pack to near-zero is provided by selectively adjusting the manner in which CCW and CW fiber leads are attached to the coil pack or the coil mount. The invention recognizes the inevitable existence of a strain differential between the CW and CCW-wound portions of a symmetrically-wound fiber coil. Leads affixed to the ends of the CW and CCW-wound halves of the coil are selectively bonded in accordance with principles for creating a counteracting temperature-dependent stress differential whereby temperature-dependent Shupe bias is substantially eliminated from the gyro output.

Abstract: A sensor coil for a fiber optic gyroscope includes fiber with an inner jacket of predetermined composition for reducing the effects of temperature-change-induced optical length asymmetry upon bias stability. Filler material of predetermined composition is combined with silicone and deposited upon the glass fiber, forming an inner jacket. The composition of the inner jacket is adjusted to thereby effect the Poisson ratio of the inner jacket and thereby reduce the isotropic thermally-induced pressure within the wound coil resulting in reduced temperature-induced optical length asymmetry and improved bias stability.

Abstract: The invention is a method and apparatus for quantitatively characterizing the pressure-induced nonreciprocity of a fiber-optic coil where the pressure-induced nonreciprocity is a property of a fiber-optic coil which pertains to the degree to which light beams, initially in phase, differ in phase as a result of traversing the fiber-optic coil in reverse directions while the fiber-optic coil is being subjected to a time-varying pressure. The method comprises the steps of applying time-varying pressure to the fiber-optic coil for a predetermined time period, measuring the phase difference of light beams traversing the fiber-optic coil in reverse directions during the predetermined time period, and obtaining a measure of the nonreciprocity of the fiber-optic coil utilizing the measured phase difference.

Abstract: A fiber optic ribbon is used for forming a sensing coil that may be used in a Sagnac effect fiber optic rotation sensor. The fiber optic ribbon provides a single radial layer per turn of the coil winder and can be made to have a quadrupole spatial turn distribution.

Abstract: A narrow-band antireflective coating is comprised of a multilayer dielectric film formed on a dielectric substrate. The antireflective coating is initially formed so that its outer layer has a thickness greater than the thickness required for antireflection. The reflectivity is monitored while outer layer is reduced in thickness to reduce the thickness of the outer layer to reduce the reflectivity.

Abstract: A potted sensor coil for a fiber optic gyroscope includes an inter-layer stress relief layer of lubricating material. The coil is wound into a known pattern. Various coil configurations can be realized in which a coating layer of lubricant relieves stressing at the interface between the outer jacket of the fiber and the coil potting material.

Abstract: A method for producing a narrow band anti-reflective film on a substrate, and the film produced by that method. The improved method being the concept of trimming the outer layer in order to correct for its thickness layers as well as those of the inner layer.

Abstract: The intensity and frequency variation due to retroscatter in a ring laser gyroscope are determined and used to correct the gyro scale factor. The orthogonal types of scatter due to dielectric variation and due to height variation, which lead to common mode phase delays of 0 and .pi./2 respectively are taken into account in calculating the correction to the scale factor. The scale factor errors are determined in terms of observable quantities. Scale factor error control is accomplished by extracting a portion of both of the two counterpropagating light beams and measuring their respective intensities, creating intensity modulation indices representative of the sum and difference intensities, using closed loop control of the real-time difference between the intensities of the beam in the ring laser gyro to reduce scale factor variation using push-pull mirror control of at least two mirrors. The residual error after push-pull mirror control minimization is output for use by a navigation system computer.

Abstract: Disclosed herein is a Solid State Split-Gain Multioscillator Ring Laser Gyroscope comprising, in a preferred embodiment, a solid state Nd:YAG crystal body defining a non-planar resonator path. Magnetic sources are provided which effectuate the Split-Gain Selective Mode Suppression Phenomena. Total internal reflection along facets of the crystal or glass allow reduced cost during manufacture of the Gyroscope. An alternative embodiment includes a solid state active medium on a chip, allowing the resonator path to be primarily lying in a glass monolithic compact solid state frame.

Abstract: A method for producing a narrow band anti-reflective film on a substrate, and the film produced by that method.Uses the concept of considering a multifilm dielectric to be an equivalent two-film dielectric, then removing a predetermined thickness of the outer, lower dielectric, film to cause the complete multifilm to become anti-reflective.When limited numbers of film materials are available, uses an EIL or effective index layer concept to obtain a predetermined index of refraction which improves the tolerance of the reflection of an anti-reflective film to film thickness errors.

Abstract: Disclosed herein is a method and apparatus for achieving scatter symmetrization in a multi-mode non-planar ring laser gyro. The retro scatter effect which results in scatter coupling in each of the left and right circular polarized sets of beams is equalized, so that the scatter coupling may be common-mode rejected during the analysis phase of the ring laser gyro operation. This equalization is achieved by unique orientation of the mirrors and the non-reciprocal polarization rotator. The non-reciprocal rotator which may be a Faraday rotator, is rotated in such a manner that its angle of rotation relative to an angle fixed at the plane of incidence of one of the mirrors of the leg is proportional to the positioning of the rotator along the axis between the mirrors of this leg. In this manner equal scatter coupling will occur in the left and right circularly polarized light and this scatter coupling may be common-mode rejected for purposes of deriving accurate rotational information.