Abstract: A tapered optical fiber component is provided that has an optical fiber with a cladded region. An optical core passes through the cladded region. The cladded region has a tapered extended first region drawn down in diameter to form an effective area region that has a predetermined effective area. The tapered extended first region is formed to adiabatically concentrate an optical signal for propagation through the effective area region of reduced diameter. The power density of the optical signal propagating through the effective area region is increased as an inverse function of the effective area.

Abstract: Disclosed herein is a multi-pole magnetic geometry for a multi-oscillator ring laser gyroscope. Multi-pole magnetic geometry configurations are disclosed which are useful for providing Faraday rotation where the multi-oscillator uses a Faraday rotator and high magnetic field effect where the nature of the multi-oscillator ring laser gyroscope is of split gain configuration. The multi-post magnetic geometry includes a plurality of top or bottom loaded diametrically opposed north and south pole axially directed magnets which are positioned substantially transverse to the optical pathway but suitable for providing axially directed magnetic fields to portions of the optical pathway only where desired. The multi-pole magnetic geometry disclosed herein substantially produces a magnetic flux that is restricted in its position to localized portions of the optical pathway with low far field effects.

Abstract: The apparatus of this invention uses a rectangular-parallelepiped prism to extract portions of the counterpropagating beams from a ring laser of a gyro. Such prism is easier to build than prisms having other than right angles. One beam bounces within the prism, but it is not perfectly reflected, and a portion of the beam is transmitted to a sensor to control the length of the ring laser cavity. The two beams are combined to produce a heterodyne signal by using two partly transmissive mirrors on two parallel surfaces of the prism, and by positioning a third side surface at a critical angle relative to one of the beams.

Abstract: An interferometer amplitude modulation reduction circuit coupled to receive an interferometer output signal from the output of a fiber optic interferometer sensor. The interferometer sensor is excited by a frequency modulated input light signal from a light source having an unwanted amplitude modulation and intensity noise signal component. The interferometer output signal has both wanted interference induced intensity modulation and also unwanted amplitude modulation and intensity noise from the unwanted amplitude modulation and intensity noise signal components present on the frequency modulated input light signal. The invention circuit has a sampling means for sampling a sample portion of the frequency modulated input light signal from the output of the light source. The sampling means detects and the sample portion signal to provide a detected sample intensity signal having a detected unwanted amplitude modulation and intensity noise signal component.

Abstract: Apparatus for stabilizing the position of the exciting electric component of a radio frequency electromagnetic field within the excited plasma of a ring laser, using two adjacent quarterwave coils, and driving the coils from a radio frequency source to ensure that the adjacent open ends of the two coils have electric field components that produce a steep gradient of electric field within the gas plasma of the ring laser.

Abstract: The rugged filter/switch cavity includes at least a two section low thermal expansion glass tubular frame, each section with a highly polished edge for abutting engagement and rigid gripping by electrostatic attraction to maintain the cavity integrity. Each frame section supports a multi-layer low loss thin film mirror in opposing relation to define the cavity gap. One mirror is fixed in the first section and the other mirror is carried by a diaphragm portion of the other section for axial movement toward and away from the first mirror to tune the cavity to different frequencies. Coaxially aligned optical fibers, affixed to each section by flexible epoxy, guide light from a broadband source including, one or more signals, into the first section, through the first mirror and back and forth between mirrors until the cavity is resonant to a signal to be selected which signal then exits the cavity via the second mirror and the other optical fiber.

Abstract: Sculling error correction means, using third or higher order correction to correct for sculling errors in apparatus for converting angle measuring and acceleration measuring signals from a vehicle set of coordinates into a stabilized set of navigation coordinates.

Abstract: Multioscillator beam-combining optics having prisms for processing both clockwise and anticlockwise elliptically polarized beams having both helicities transmitted through a partly transmissive corner mirror. The optical structure uses a thin-film polarizer with a waveplate which is not necessarily a quarter wave plate. Further, the waveplate thickness is determined so that one component of elliptically polarized light is converted into a linearly polarized beam. A thin film polarizer then blocks the linearly polarized beam. The waveplate principal crystal axes form a nominally forty five degree angle with the s and p polarization axes. Techniques are used to keep extraneous birefringence of the beams to a minimum.

Abstract: An integrated optics device has a substrate of lithium niobate (LiNbO.sub.3) with at least one optical waveguide. A slot formed in the edge of the substrate has end wall that exposes an end surface of the optical waveguide formed at an end surface angle with the optical axis of propagation to reduce reflected light in the optical waveguide. A length of optical fiber. The optical fiber has an end face formed at an end face angle with the direction of the propagation of light in the optical fiber. The slot is formed to receive the optical fiber. The optical fiber is positioned in the slot with the end face butt-coupled to the end surface of the optical waveguide to form an interface such that light may propagate between the optical waveguide and the optical fiber. A means for mounting the substrate. The optical waveguide is extended to an input junction with a center wave guide and with an sense waveguide.

Abstract: Disclosed herein is an External Scatter Removal System for Ring Laser Gyroscopes (such as a Split Gain Multioscillator) comprising a prism mounted on an optoisolator, wherein light transmitted out at least one of the mirrors of the Gyroscope passes into the prism and detector system, while oppositely directed backscattered light from the prism components is not returned to the gyroscope frame's internal optical path, thereby limiting any appreciable backscatter from interfering with an accurate measurement of the rotation rate of the gyroscope.

Abstract: A yarn tensioner or brake for textile knitting machines having several tensioners on a support rod, each tensioner having a pair of tension cups which are pressed against each other by compressed springs supported from a stationary support. In a first embodiment, a stationary tension cup forms the stationary support and a floating tension cup alternates with respect to a stationary tension cup of an adjacent tensioner. The stationary tension cups have cylindrical protruding guides which slip fit into and guide the floating tension cups. In another embodiment, a stationary support supports compressed springs on both sides. The stationary support is formed of a circular support wall which has cylindrical protrusions on opposing sides and sized to slip fit into respective floating tension cups. A pair of stationary supports positioned on the support rod to support and guide opposing floating tension cups against each other. Each respective floating tension cup is driven by a respective coil spring.

Abstract: A wavelength stabilization apparatus and method for a superfluorescent source comprising a SFS (superfluorescent source) comprising a fiber with a core doped with lazing material. The SFS source produces SFS light with an SFS wavelength when pumped with pump light from a pump light source having a pump light wavelength. An output controller responds to a sample of the SFS light and operates to maximize the power of the sample of SFS light by automatically adjusting the pump light wavelength. The output controller also has a pump power controller responsive to a sample of the pump light from the pump light source for stabilizing the output power of the sample of the pump light with respect to a predetermined reference output power level.

Abstract: A phase modulation control apparatus is taught in combination with an interferometer excited by a coherent light source providing a light beam to the interferometer having first and second optical paths. The interferometer senses a physical quantity such as pressure. The interferometer is coupled to provide an optical signal containing information providing a measure of the physical quantity via first and second interfering beams to a detector. The detector provides a composite output signal. The invention phase modulation control apparatus has a modulation means responsive to a modulating frequency signal and a phase modulation control signal to provide a frequency modulating factor signal for frequency modulating at least a portion of the light beam to provide a phase modulation between the first and second interfering beams at a carrier frequency. The composite output signal has at least four harmonic signals referenced to the carrier frequency.

Abstract: An inexpensive fiber optic gyro using a fiber optic sensing coil that is fed from two single-mode light carriers such as an optical waveguide or optical fibre. The light carriers obtain their energy, through a mode splitter, from a double-mode light carrier. The double-mode carrier is, in turn, energized by an at least partially coherent light source through a single-mode light carrier. The light source is preferably a laser. Detectors are attached to light carriers which tap different predetermined positions along the double-mode waveguide to produce substantially sinusoidal signal functions of sensed rotation.

Abstract: The invention temperature controlled package comprises a case having sidewalls that form a closed perimeter; a cover; and a base having an input surface and an output surface. The sidewalls are integrally coupled to the base input surface to define an interior region. A heatsink has a top surface and a bottom surface. The heatsink bottom surface is attached to the input surface of a thermoelectric cooler. The bottom surface of the thermoelectric cooler is coupled to the base input surface of the case. The thermoelectric cooler responds to a control signal to move heat from the thermoelectric cooler input surface to the thermoelectric cooler output surface. In a first alternative embodiment, a laser diode coupled to the heat sink responds to an electrical input signal to providing an optical laser output signal. The optical output of the laser diode is coupled via a optical fiber through a fiberoptic feedthrough in a sidewall. The interior region is filled with xenon gas.

Abstract: Apparatus and methods for reducing and preventing polarization fading in unbalanced measuring interferometers. An extended interferometer having a plurality of sensors and a compensating interferometer are used. They are driven from a pulsed optical signal source wherein the optical signal comprises sequences of two pulses each. To prevent polarization fading the polarization of a predetermined one of each two-pulse sequence is switched, preferably orthogonally, from sequence to sequence. Interference pulse output groups are produced for each two-pulse driving sequence. Each output group has the same number of usable pulses as the number of sensors in the interferometer.

Abstract: A protected fiber optical splice and a method for making the protected splice. The protective structure encapsulates first and second spliced optical fibers. The fibers are preferably fusion spliced. The protective structure includes a rigid tube surrounding the splice and its adjacent regions of the spliced fibers. A plastic such as an epoxy or moldable plastic is injected into the tube between the substantially axially centered fibers and splice, and the interior wall of the tube. Two molding fixtures are preferably surrounding the two ends of the tube, for injecting the moldable plastic into the tube and for shaping the portions of the structure external to the the tube ends.

Abstract: A wavelength stabilization apparatus and method for a superfluorescent source comprising a SFS (superfluorescent source) comprising a fiber with a core doped with lzaing material. The SFS source produces SFS light with an SFS wavelength when pumped with pump light from a pump light source having a pump light wavelength. An output controller responds to a sample of the SFS light and operates to maximize the power of th esample of SFS light by automatically adjusting the pump light wavelength. The output controller also has a pump power controller responsive to a sample of the pump light from the pump light source for stabilizing the output power of the sample of the pump light with respect to a predetermined reference output power level.

Abstract: A passive ring resonator gyroscope comprising a single piece body having an integral first and second resonator cavity. The first resonator cavity has a single frequency laser means with internal cavity mounted reflective surfaces to provide a single frequency light source to the second resonator cavity. The single frequency light source is sharply tuned. The second resonator cavity is a passive high Q evacuated cavity having a closed second optical path tuned to resonate at the single frequency light frequency of the first resonator cavity. A cavity servo means is provided for controlling the resonant frequency of the second resonator high Q cavity to simultaneously and substantially track the resonant frequency of the first resonator high Q cavity. An output servo means is provided for detecting the change in frequency of the single frequency light within the second resonator in response to said body rate input to the sensitive axis and for providing an output signal.

Abstract: An integrated optics decorrelator device with a first integrated optics junction. The first optics junction has two input paths and at least one output path formed as a Y-shaped assembly of two mono-modal optical waveguides joined at a node with a central multi-modal optical waveguide. The central multi-modal optical waveguide segment has an output end. A second integrated optics junction has two output paths formed as a Y-shaped assembly of two output mono-modal optical waveguides joined at the output end of the central multi-modal optical waveguide segment. The first integrated optics junction and the second integrated optics junction are formed inside a refractive medium having a lower refractive index than the refractive index of the waveguides.