Abstract: Systems and methods are provided for utilizing polarization parameters obtained from an optical network to determine vibrations in optical fibers using coherent optics equipment and machine learning techniques. A method, according to one implementation, includes the step of obtaining a time-series dataset that includes measurements of polarization characteristics of light traversing an optical fiber of an optical network. The method also includes the step of detecting vibration characteristics of the optical fiber based on the time-series dataset. In some implementations, the time-series dataset may be a multi-variate dataset and the polarization characteristics may be related to transients in a State of Polarization (SOP). The SOP, for example, may be represented by an amplitude and a phase of an electric field vector and may be defined as having one of a linear polarization, elliptical polarization, and circular polarization.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing systems, methods, and structures that advantageously are employed to determine the location and depth of underground fiber-optic facilities that may be carrying telecommunications traffic.

Abstract: A long-distance optical cable physical safety monitoring system, including a light source module, a light interference module, a sensing module, a reflection module, a photovoltaic conversion module, and a data processing module. The light interference module is use for dividing a light beam into multiple light beams; the sensing module is use for transmitting the multiple light beams; the reflection module is used for reflecting the multiple light beams to make the light interference module to output an interference signal; the photovoltaic conversion module is used for converting the interference signal to obtain a data signal; the data processing module is used for processing the data signal. The long-distance optical cable physical safety monitoring system is passive, low in energy consumption, anti-jamming, low in false positive rate, simple in construction, and convenient in maintenance.

Abstract: One example includes a FOG assembly including a spool that includes a flattened portion corresponding to a flange comprising an axial center corresponding to a sensitive axis about which an associated FOG system is configured to measure rotation. The FOG assembly also includes a magnetic shield arranged as a capped concentric cover about the sensitive axis and coupled to the spool and the flange to create a toroidal cavity between the magnetic shield and the flange. A fiber coil is disposed within the toroidal cavity and coupled to the flange. The fiber coil includes an optical fiber which is counter-wound in first and second orientations. The fiber coil has an axial dimension along the sensitive axis that is less than or equal to approximately 160% of a radial width corresponding to a difference between an outer radius and an inner radius of the fiber coil.

Abstract: An embodiment of a method of manufacturing a fiber optic cable includes selecting a cable support structure configured to support an optical fiber sensor, adhering the optical fiber sensor to the cable support structure by applying a temporary adhesive, and installing a protective layer around the cable support structure and the temporarily adhered optical fiber sensor. The method further includes removing a bond between the optical fiber sensor and the temporary adhesive, wherein removing the bond includes injecting a debonding material into a space formed between the cable support structure and the protective layer, and injecting a permanent adhesive into the space, the permanent adhesive configured to immobilize the optical fiber sensor relative to the protective layer and allow strain to be transferred from the protective layer to the optical fiber sensor.

Abstract: A fiber is wound into first and second coils lying substantially in respective first and second planar directions having a substantially orthogonal relationship. The first and second coils are configured to result in respective first and second birefringences that are dominated by bend-induced birefringence. The first and second birefringences have respective axes that are rotated with respect to each other in real space by an angle that is substantially equal to 90 degrees. Light traveling through the fiber has a state of polarization that evolves in substantially opposite directions as it travels respectively through the first and second coils. The first and second coils are configured such that light traveling through the fiber acquires respective, substantially opposite first and second phase shifts. Light traveling through the fiber acquires respective first and second differential group delays that substantially compensate for each other.

Abstract: An optical rotation sensor includes a Fabry Perot laser having an active gain medium for generating first and second light beams, a closed optical path through which the first and second light beams counter-propagate and first and second mirrors coupled to respective ends of the closed optical path. The first minor is a ring mirror having a complex valued reflectivity that varies with a rotation rate of a frame within which the optical rotation sensor is placed. A detector is coupled to an output of the Fabry Perot laser to measure an output intensity thereof.

Abstract: A fiber-optic interferometer comprising an optical fiber wound to form a fiber coil into which two partial light beams of a first light source can be coupled. The Bragg structure is integrated into the fiber coil. Said Bragg structure comprises an optical fiber having a periodically varying refractive index. In a method for determining physical state parameters in the interior of a fiber coil of a fiber optic interferometer information about physical state parameters in the interior of the fiber coil is obtained on the basis of the reflection wavelength of a Bragg structure comprising an optical fiber having a periodically varying refractive index is integrated into the fiber coil.

Abstract: An optical fiber coil including an optical fiber having a first end and a second end, the optical fiber including first, second, third and fourth segments, wherein the first segment is contiguous with the second segment, the second segment is contiguous with the third segment, and the third segment is contiguous with the fourth segment, and plural substantially planar layers stacked along a coil axis, the layers including a first planer layer formed from the first segment, a second planar layer formed from the second segment, a third planar layer formed from the third segment, and a fourth planar layer formed from the fourth segment, wherein the fourth planar layer is positioned between the first planar layer and the second planar layer, and wherein the second planer layer is positioned between the third planer layer and the fourth planar layer.

Abstract: An all-fiber interferometric fiber optic gyroscope having a minimum reciprocal configuration is described. The gyroscope comprises a polarized light source, a light detector, a light source coupler, a fiber optic loop coupler, and a polarization maintaining fiber optic loop. A first port of the light source coupler is counter-axially coupled to an output end of the polarized light source, and a second port of the light source coupler on the same side as the first port is coupled to the light detector. A third port on the other side of the light source coupler is counter-axially coupled to the fiber optic loop coupler, and the fiber optic loop coupler is counter-axially coupled to the polarization maintaining fiber optic loop. The light source splits the input polarized light and polarizes the optical signal propagated along a transmission arm alone, where the first and third ports are on the same transmission arm.

Abstract: An optical fiber with a b-stageable hybrid adhesive coating includes an optical fiber and an outer jacket. The outer jacket includes at least one layer that includes a partially cured b-stageable hybrid adhesive.

Abstract: A Fiber-optic current sensor for sensing electric current carried in an electric conductor (18). Its optical section comprises: a light source (1); a directional coupler (2) with two ports (2A, 2B) of two arms each; a radiation polarizer (3); a polarization modulator (4); a fiber line (17) coupled to a current-sensing fiber loop (11); a mirror (10); and a photodetector (22). The first port of the coupler (2) is coupled to the light source (1) and to the photodetector (22). Its second port is coupled via the radiation polarizer (3) to the polarization modulator (4). The polarization modulator comprises a magneto-sensitive element (5), around which a solenoid (6) is wound. The fiber loop (11) comprises a magneto-sensitive optical fiber with embedded linear birefringence. An electronic section comprises a signal generator (21) which drives the solenoid (6); and a signal processing unit which receives the optical signal from the photodetector (22).

Abstract: An all-fiber interferometric fiber optic gyroscope having a minimum reciprocal configuration is described. The gyroscope comprises a polarized light source, a light detector, a light source coupler, a fiber optic loop coupler, and a polarization maintaining fiber optic loop. A first port of the light source coupler is counter-axially coupled to an output end of the polarized light source, and a second port of the light source coupler on the same side as the first port is coupled to the light detector. A third port on the other side of the light source coupler is counter-axially coupled to the fiber optic loop coupler, and the fiber optic loop coupler is counter-axially coupled to the polarization maintaining fiber optic loop. The light source splits the input polarized light and polarizes the optical signal propagated along a transmission arm alone, where the first and third ports are on the same transmission arm.

Abstract: An optical gyroscope is provided for measuring a small angular difference. The gyroscope includes a laser, a pre-selection polarizer, a first beam splitter, a coil of optical fiber, a second beam splitter, a post-selection polarizer, a spectrometer and an analyzer. The laser emits a pulse beam of coherent photons. The beam has pulse duration ?. The pre-selection polarizer pre-selects the photons, and the first beam splitter separates the photons by their horizontal |+ and vertical |? polarization eigenstates. These beams are launched into a fiber optical coil of radius r, which preserves polarization. The coil rotates by a difference rotation angle ??. The second beam splitter recombines the polarized photon beams as they exit the coil. The post-selection polarizer post-selects the photons. The spectrometer captures the post-selected photons and measures the associated frequency translation ??.

Abstract: An all-fiber interferometric fiber optic gyroscope having a minimum reciprocal configuration is described. The gyroscope comprises a light source, a light detector, a light source coupler, a fiber optic loop coupler, and a polarization maintaining fiber optic loop. A first port of the light source coupler is coupled, with polarization axis alignment, to an output end of the light source, and a second port of the light source coupler on the same side as the first port is coupled to the light detector. A third port on the other side of the light source coupler is coupled, with polarization axis alignment, to the fiber optic loop coupler, and the fiber optic loop coupler is coupled, with polarization axis alignment, to the polarization maintaining fiber optic loop. The light source splits the input light and polarizes the optical signal propagated along a transmission arm alone, where the first and third ports are on the same transmission arm.

Abstract: A method in which a ribbon fiber, containing a plurality of waveguides each having a first end and a second end, is wound into a coil and the second end of a first waveguide is coupled together with the first end of a second waveguide such that light in said first waveguide will transfer to said second waveguide.

Abstract: Disclosed is a fiber optic interferometer including: a wideband optical source having a decoherence time ?DC; a coil including N turns of a fiber optic with length L; an optical element separating the incident beam into first and second beams coupled to first and second ends of the fiber respectively, so the first beam travels through the fiber optic in a first direction and the second beam travels through the fiber optic in a counter propagating direction; and a detector detecting the intensity of the output beam. The fiber optic is a high polarization mode dispersion type, and the length L of the fiber optic coil is more than twice the fiber correlation length, so the fiber operates in a coupled PMD mode, and the propagation differential group delay between two orthogonal polarization states, accumulated over the length of the fiber, is greater than the decoherence time of the source.

Abstract: A semiconductor ring laser gyroscope includes: a semiconductor laser for emitting two lights from both end surfaces thereof; an optical fiber ring through which the two lights propagate in the respective opposite directions, which, in association with the semiconductor laser, constitutes a laser resonator, and which includes a sensor coil made of an optical fiber wound in a multilayer manner; and an optical detection unit for detecting a rotational angular velocity based on beat frequencies of the two lights, wherein an expression: 2?Fbeat—max<Frlg?10?Fbeat—min is satisfied in which Frlg=C/nL, where ?Fbeat—max and ?Fbeat—min are beat frequencies corresponding respectively to the upper and lower limits of an angular velocity measuring range, Frlg is a ring resonance frequency, C is a light speed, n is a refractive index of the optical fiber, and L is an overall length of the optical fiber.

Abstract: An all-fiber interferometric fiber optic gyroscope having a minimum reciprocal configuration is described. The gyroscope comprises a polarized light source, a light detector, a light source coupler, a fiber optic loop coupler, and a polarization maintaining fiber optic loop. A first port of the light source coupler is counter-axially coupled to an output end of the polarized light source, and a second port of the light source coupler on the same side as the first port is coupled to the light detector. A third port on the other side of the light source coupler is counter-axially coupled to the fiber optic loop coupler, and the fiber optic loop coupler is counter-axially coupled to the polarization maintaining fiber optic loop. The light source splits the input polarized light and polarizes the optical signal propagated along a transmission arm alone, where the first and third ports are on the same transmission arm.

Abstract: An optical fiber vibration sensor includes a light source, an optical receiver, an optical dividing/coupling portion, a signal processing unit, and a fiber loop portion made of an optical fiber. A part of an optical fiber composing the fiber loop portion is installed inside a housing of a main body of the optical fiber vibration sensor as an optical fiber for delay and another part of the optical fiber composing the fiber loop portion is installed outside the housing as a vibration detecting optical fiber.

Abstract: A fiber-optic sensor includes an optical fiber coil and a laser source optically coupled to the coil. Light from the source is transmitted to the coil as a first optical signal and a second optical signal counter-propagating through the coil. The optical paths of the first optical signal and the second optical signal are substantially reciprocal with one another and the first optical signal and the second optical signal are combined together after counter-propagating through the coil to generate a third optical signal. The laser source is frequency-modulated or can have a coherence length longer than a length of the coil.

Abstract: An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler. The first optical signal has a group velocity and a phase velocity while propagating through at least a portion of the optical waveguide, the group velocity less than the phase velocity. An interference between the first optical signal and a second optical signal is affected by relative movement between the optical waveguide and the at least one optical coupler.

Abstract: A fiber-optic sensor, a method of configuring a fiber-optic sensor, and a method of using a fiber-optic sensor are provided. The fiber-optic sensor includes an optical fiber coil having a length and a laser source optically coupled to the coil. The laser source has a coherence length. Light from the source is transmitted to the coil as a first signal propagating along the coil in a first direction and a second signal propagating along the coil in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the coil to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters.

Abstract: An optical sensor includes an optical coupler configured to receive a first optical signal and to split the first optical signal into a second optical signal and a third optical signal. The optical sensor further includes a Bragg fiber in optical communication with the optical coupler. The second optical signal and the third optical signal counterpropagate through the Bragg fiber and return to the third port and the second port, respectively.

Abstract: Disclosed is a differential birefringent fiber frequency-modulated continuous-wave (FMCW) Sagnac gyroscope for measuring rotation velocity. The gyroscope uses a 90°-twisted single-mode birefringent fiber coil as a double unbalanced fiber-optic FMCW Sagnac interferometer, and uses the phase difference between the two beat signals from the fiber coil to determine the rotation velocity. This gyroscope can eliminate the nonreciprocal phase drift and provide a doubled resolution.

Abstract: An active sensor 10 is positioned on an outside of a pipe 60 so as to detect a thickness of the pipe. The active sensor comprises: an oscillator 15 capable of inputting oscillatory waves into the pipe and sweeping a frequency of the oscillatory waves within a desired range; and an optical fiber sensor mounted on the pipe, the optical fiber sensor detecting the oscillatory waves generated in the pipe.

Abstract: A method and apparatus for reducing the thermal induced errors in an IFOG system. The apparatus including a highly thermally conductive material configured to encapsulate a waveguide of an interferometric fiber optic gyroscope (IFOG). The highly thermally conductive material more evenly distributes thermal changes encountered by a sensing coil of the IFOG thereby substantially reducing errors in the IFOG system.

Abstract: A multiple nested interferometric fiber optic gyroscope system having varying functions may include a first fiber optic coil, a second fiber optic coil which is smaller than the first fiber optical coil and nested within and transversely to the first fiber optic coil, and a third fiber optic coil which is smaller than the second fiber optical coil and nested within and transversely to the second fiber optic coil.

Abstract: A method of constructing a fiber-optic gyroscope includes optically coupling first and second optical fibers to an optical path of an interferometer having an outer surface, coupling at least a portion of the first and second fibers to the outer surface, and optically coupling the first and second fibers to an optical path of an integrated optics chip (IOC).

Abstract: An octupole winding pattern for winding a fiber optic coil includes at least two layers of an eight-layer winding pattern having an end fiber optic coil diameter formed in an opposite direction as a substantial portion of a remaining portion of the respective layer. The selectively arranged octupole winding pattern may be used in a fiber optic gyroscope. A spool onto which the fiber optic coil is wound may be removable. Preferably, the octupole winding pattern is advantageously arranged to provide a substantial amount of optical symmetry with respect to a winding centerline of the fiber optic coil. In addition, the octupole winding pattern provides a substantial amount of geometric, mechanical, and thermal symmetry.

Abstract: A fiber optic coil assembly and a method of winding the same include a fiber optic coil configured to eliminate a jog zone, which is found in conventionally fiber optic coil assemblies and tends to weaken the coil. The fiber optic coil assembly includes at least two layers of coil. A first layer is cylindrically wound in a first rotational direction and in a first linear direction and includes coil diameters located substantially parallel to one another and extending over the first linear direction. A first lead portion extends from an end of the first layer through an opening defined by the wound first layer. A second layer is formed in a similar manner as the first layer, except it is wound in an opposite rotational direction. Additional layers may be included consistent with the winding process of the first or the second layer, respectively.

Abstract: An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler. The first optical signal has a group velocity and a phase velocity while propagating through at least a portion of the optical waveguide, the group velocity less than the phase velocity. An interference between the first optical signal and a second optical signal is affected by perturbations to at least a portion of the optical sensor.

Abstract: A method for winding a crossover-free fiber optic coil sensor comprising: attaching a fiber optic cable to an outer edge of a coil form, wherein the coil form comprises a first side and a second side; forming a first outside-in coil layer on the first side of the coil form using a first winding head; attaching a first inside-out separator on top of the first outside-in coil layer; forming a first inside-out coil layer on top of the first inside-out separator using the first winding head; forming a second outside-in coil on the second side of the coil form using a second winding head; attaching a second inside-out separator on top of the second outside-in coil layer; and forming a second inside-out coil layer on top of the second inside-out separator using the second winding head.

Abstract: A fiber optic sensor coil and method of forming a fiber optic sensor coil including a plurality of turns of a first segment of optical fiber wound in a clockwise direction and a plurality of turns of a second segment of optical fiber wound in the counterclockwise direction. The turns of the first segment and of the second segment together forming a plurality of layers of turns of the optical fiber. A restraining ring covers an outermost layer of the plurality of layers of turns of optical fiber. The restraining ring includes a plurality of openings formed therein and provides a compressive force to the plurality of turns of the optical fiber.

Abstract: A method for winding a crossover-free fiber optic coil sensor comprising: attaching a fiber optic cable to an outer edge of a coil form, wherein the coil form comprises a first side and a second side; forming a first outside-in coil layer on the first side of the coil form using a first winding head; attaching a first inside-out separator on top of the first outside-in coil layer; forming a first inside-out coil layer on top of the first inside-out separator using the first winding head; forming a second outside-in coil on the second side of the coil form using a second winding head; attaching a second inside-out separator on top of the second outside-in coil layer; and forming a second inside-out coil layer on top of the second inside-out separator using the second winding head.

Abstract: A sensing coil assembly and method for attaching a sensing coil to a support structure are provided for a fiber optic gyroscope. The method comprises affixing a first support surface of the support structure to a first mounting surface of the sensing coil via a first preformed adhesive, and affixing a second support surface of the support structure to a second mounting surface of the sensing coil via a second preformed adhesive. The sensing coil assembly comprises a support structure having first and second support surfaces and having a substantially cylindrical hub coupled between the first and second opposing surfaces, an optical fiber coil surrounding at least a portion of the substantially cylindrical hub, and first and second preformed adhesive patterns affixing the optical fiber coil to the first and second opposing surfaces. The first support surface opposes the second support surface.

Abstract: A sensing coil is provided for optically guiding counter-propagating light beams in a fiber optic gyroscope. The sensing coil comprises a plurality of layers of an optical fiber having a winding direction. The plurality of layers comprises inner layers, middle layers, and outer layers. The middle layers comprise first and second input ends configured to receive the counter-propagating light beams. At least one of the inner layers, middle layers, and outer layers is coupled with a different one of the inner layers, middle layers, and outer layers while maintaining the winding direction. A method is provided for winding an optical fiber, having first and second connecting ends, to form a sensing coil for a fiber optic gyroscope having a winding direction.

Abstract: A sensing coil assembly and method for attaching a sensing coil to a support structure are provided for a fiber optic gyroscope. The method comprises affixing a preformed adhesive to a mating surface of a mounting structure, and coupling an inner surface of the sensing coil to the mating surface of the mounting structure via the preformed adhesive. The mating surface is substantially cylindrical or conical. The sensing coil assembly comprises a hub having a mating surface, an optical fiber coil having an inner surface encircling at least a portion of the mating surface, and a preformed adhesive pattern affixing the mating surface to the inner surface. The mating surface of the hub is substantially cylindrical or conical.

Abstract: In accordance with at least one embodiment of the present invention, a system includes a gyroscope and a flight vehicle operatively connected to the gyroscope. The gyroscope includes a length of fiber optic cable arranged in loop and configured to surround an interior loop region. The gyroscope further includes a control unit configured to send and receive light through the fiber optic cable and measure a rate of rotation of the gyroscope. A portion of the flight vehicle is located within the interior loop region.

Abstract: A fiber optic gyroscope (FOG) includes a sensing coil with a particular magnetic sensitivity magnitude and direction with respect to the geometric axis of the sensing coil. The FOG also includes a plurality of magnetic compensators. Each magnetic compensator is fabricated so as to have a particular magnetic sensitivity magnitude and direction, the magnitude being comparable to that of the sensing coil, with large tolerances relative to the magnitude and direction. The compensators are positioned relative to one another and to the sensing coil such that the combined magnetic sensitivities of the compensators cancel the magnetic sensitivity of the sensing coil.

Abstract: Adhesive system and method are provided for affixing a fiber optic coil to a hub with an adhesive in a fiber optic gyroscope. The adhesive system comprises a fiber optic coil, a substantially cylindrical hub configured to couple with the fiber optic coil, and an array of adhesive dots affixing the fiber optic coil to the substantially cylindrical hub. The method comprises forming an array of adhesive dots on an outer surface of the hub, and affixing the fiber optic coil to the outer surface of the hub via the array of adhesive dots.

Abstract: An optical return loss detecting device is provided for measuring the optical return loss (ORL) of a device under test (DUT). The detecting device comprises a light source, an optical isolator connected to the light source for preventing reflected light by the DUT entering the light source, a first optical coupler connected to the isolator, a second optical coupler connected to the first coupler and the DUT respectively, and a module communicating with the second coupler for performing test and calculation functions thereof.

Abstract: A method of applying a moisture barrier seal to a fiber optic coil includes mounting a fiber optic coil in a vacuum deposition chamber, so as to expose a large exterior surface area of the fiber optic coil to an interior portion of the deposition chamber. The method further includes reducing the air pressure within the chamber to a value that is less than ambient pressure outside of the chamber. The method further includes introducing a vapor form of a non-porous material, preferably parylene, into the chamber. The vapor form of the non-porous material changes into a solid state upon contact with the fiber optic coil, so as to form a conformal coat on the fiber optic coil.

Abstract: A fiber optic sensing coil is formed by winding a non-coated optical fiber in a substantially circular loop. The non-coated optical fiber includes a core and a cladding. Once the non-coated optical fiber is wound, turns of the non-coated optical fiber are fused so that the cladding of the individual turns of the optical fiber are fused to one another at points of mutual contact.

Abstract: An optical gyroscope (100) has a detection light guide body (100S) and a light measuring board (140). The detection light guide body (100S) is formed by stacking light guide layers (110, 120) and protective layers (130) alternately. An eddy-shaped light guide path section is provided in each of the light guide layers (110, 120), and the light guide path sections are optically connected to each other through said protective layers (130) to form an integral light guide path (100L). One end (100La) of the light guide path (100L) is directly connected to the light measuring board (140), and another end (100Lb) of the same is connected to the light measuring board (140) through an optical fiber (143).

Abstract: An optical fiber coil for a fiber-optic measuring device and a method for producing it. An opitcal fiber is applied to a winding body in a quadrupole winding pattern in directly successive winding layers such that the turns of the individual winding layers have, at irregular spacings, as large a number of crossover points as possible. The spacings between the individual turns in each winding layer are variable, but, on average, they correspond to approximately half the diameter of the optical fiber. The optical fiber coil is preferably applied to the winding body without the use of fixing and buffer means.

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: The invention is directed to a Faraday-type current sensor which is less susceptive to effects caused by rotation, acceleration and vibration of the sensor coil. The sensor coil of the invention includes a first coil section which forms the current sensing coil and a second coil section which is optically connected to the first coil section and forms a compensation or “bucking” coil. The optical fiber of the first coil section preferably has an almost zero birefringence and is connected in series with the optical fiber of the second coil section which preferably has a large birefringence. The illuminating radiation propagates through the sensor coil in such a way, as viewed along the coil axis, that the propagation direction of the radiation in the first coil section with respect to the coil axis is opposite from the propagation direction in the second coil section.

Abstract: A method and system for winding optical fiber. In an embodiment, the method and system can be used to tune a fiber optic gyroscope (FOG) for a desired eigenfrequency and/or scale factor. A FOG assembly can include an inner coil that can have a normal and a reverse breakout point, a normal and a reverse lead emanating therefrom, and a normal and a reverse splice that can be connected at normal and reverse connection points. The coil can be wrapped to include a reversal where the reverse section of fiber changes direction in which it is wrapped on a spool. The fiber length can be adjusted based on the desired eigenfrequency.

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.