Abstract: A system comprising a nonlinear medium (NLM), an optical transduction module, a dual homodyne detector and a processor is provided. The NLM receives at least a pump beam and issues the pump, probe and conjugate beams, where the beams are linearly polarized. Optics route the probe, the conjugate or both beams to the sample. The sample imparts polarization rotation to light that interacts therewith. The optical transduction module imparts to the interacted light an optical phase shift that is a 1:1 transduction of the polarization rotation, where at least one of the probe light or the conjugate light carries the imparted optical phase shift. The processor obtains the optical-phase shift based on respective detection signals from the dual homodyne detector and determines, based on the obtained optical-phase shift, at least one of a Faraday polarization rotation, a Kerr polarization rotation or a spin noise spectrum.

Abstract: A detecting device configured to detect chemical or biological species in a given environment, includes a matrix-array sensor formed from opto-mechanical discs that are optically and mechanically resonant, able to bind to species of the environment, and arranged in rows and columns. The opto-mechanical discs of a given row are optically coupled to the same optical waveguide. Actuating electrodes are provided in order to ensure the mechanical resonance of the opto-mechanical discs. One p-n junction is associated with each opto-mechanical disc, the junctions of a given column being electrically connected to the same biasing electrode, so as to block the flow through the corresponding opto-mechanical disc of a parasitic electrical current.

Abstract: A method for optimization of photonic devices is disclosed. The method includes receiving a set of unconstrained latent variables; mapping the set of unconstrained latent variables to a constrained space to generate a constrained device; calculating the permittivity across each element of the constrained device; determining a permittivity-constrained width gradient based at least partially on the permittivity across each element; and optimizing the set of unconstrained latent variables by at least partially using the permittivity-constrained width gradient.

Abstract: Systems and methods for reducing rotation sensing errors from laser source signal and modulation cross-talk are provided herein. An RFOG includes a fiber optic resonator; a first laser source that produces a first light wave at a first carrier frequency and a first cross-talked portion at a second carrier frequency wave for propagating in a first direction, wherein a second cross-talked portion propagates in a second direction that is opposite to the first direction; a second laser source that produces a second light wave for propagating in the second direction at a second carrier frequency, and having a third cross-talked portion that propagates in the first direction, a first modulator that modulates the first light wave by suppressing light at the first carrier frequency and the second cross-talked portion at the second carrier frequency, and photodetectors that generate signals from the modulated first light wave and the second light wave.

Abstract: An integrated photonics optical gyroscope fabricated on a silicon nitride (SiN) waveguide platform comprises a first silicon nitride (SiN) waveguide layer that constitute a rotation sensing element; and, a second SiN waveguide layer with additional silicon nitride (SiN) waveguide-based optical components that constitute a front-end chip to launch light into and receive light from the rotation sensing element. The two SiN waveguide layers can be stacked together to have a multi-layer configuration vertically coupled with each other. External elements (e.g., laser, detectors, phase shifter) may be made of different material platform than SiN and can be hybridly integrated to the SiN waveguide platform. The phase shifters can be made of aluminum nitride (AlN) or strontium bismuth titanate (SBT).

Abstract: An integrated photonics optical gyroscope fabricated on a silicon nitride (SiN) waveguide platform comprises a first straight waveguide to receive incoming light and to output outgoing light to be coupled to a photodetector to provide an optical signal for rotational sensing. The gyroscope comprises a first microresonator ring proximate to the first straight waveguide. Light evanescently couples from the first straight waveguide to the first microresonator ring and experiences propagation loss while circulating as a guided beam within the first microresonator ring. The guided beam evanescently couples back from the first microresonator ring to the first straight waveguide to provide the optical signal for rotational sensing after optical gain is imparted to guided beam to counter the propagation loss. In a coupled-ring configurations, the first microresonator ring acts as a loss ring, and optical gain is imparted to a second microresonator ring which acts as a gain ring.

Abstract: A cavity optomechanical vibratory gyroscope pertains to technical fields of resonant optical gyroscopes and micro-optical-electro-mechanical systems. A novel cavity optomechnical Coriolis vibratory micro gyroscope is realized based on ring micro rings and the Coriolis vibration principle, and driving and detection thereof is completely different from conventional electric or magnetic means. Based on the principle of angular velocity sensitive structures in the conventional Coriolis vibratory gyroscopes, full-optical driving, detecting and sensing of a vibratory gyroscope are achieved using cavity optomechnical technologies, which fundamentally suppresses various noises (including thermal noise, cross interference, connection point noise and quadrature error) introduced by electric or magnetic driving. Besides, displacement (vibration) sensing information is obtained according to a linear relationship between frequency shift and light amplitude in the micro cavity optomechnical effect.

Abstract: A method and system is provided for estimating and compensating for gyro bias in gyro-stabilized systems. The method includes comparing an output of a gyroscope to a reference measurement; estimating a bias of the gyroscope based on the comparison using a Kalman filter; and adjusting a control output of the gyro-stabilized system with the estimated bias to maintain a position of the gyro-stabilized system.

Abstract: A beam combiner array assembly including an array block having a back wall and a front surface and a plurality of aligned and sealed channels extending from the back wall to the front surface. A lens array including a plurality of lenses is secured to the front surface of the block so that one of the lenses is aligned with each channel, and a plurality of fiber flanges are secured to the back wall of the block so that a separate one of the flanges is aligned with each channel. A hollow core fiber extends through each flange and the back wall so that an end of the fiber is positioned within one of the channels. A beam that propagates down each fiber is emitted into the channel, focused by the lens and emitted from the assembly as a collimated beam.

Abstract: The present disclosure relates to system-level integration of lasers, electronics, integrated photonics-based optical components and a sensing chip. Novel waveguide design on the integrated photonics chip, acting as a front-end chip, ensures precise detection of phase change in a fiber coil or a sensing chip having a waveguide coil or ring resonator, where the sending chip is coupled to the front end chip. Strip waveguides are designed to primarily select TE mode over TM mode when laser light is coupled into the integrated photonics chip. A plurality of mode-selective filters, based on multi-mode interference (MMI) filter, a serpentine structure, or other types of waveguide-based mode-selective structure, are introduced in the system architecture. Additionally, implant regions are introduced around the waveguides and other optical components to block unwanted/stray light into the waveguides and optical signal leaking out of the waveguide.

Abstract: The invention provides methods and devices for generating optical pulses in one or more waveguides using a spatially scanning light source. A detection system, methods of use thereof and kits for detecting a biologically active analyte molecule are also provided. The system includes a scanning light source, a substrate comprising a plurality of waveguides and a plurality of optical sensing sites in optical communication with one or more waveguide of the substrate, a detector that is coupled to and in optical communication with the substrate, and means for spatially translating a light beam emitted from said scanning light source such that the light beam is coupled to and in optical communication with the waveguides of the substrate at some point along its scanning path. The use of a scanning light source allows the coupling of light into the waveguides of the substrate in a simple and cost-effective manner.

Abstract: Methods and systems for a light source arrangement supporting direct coupling to a photonically enabled complementary metal-oxide semiconductor (CMOS) chip are disclosed. The arrangement may include a laser, a microlens, a turning mirror, reciprocal and/or non-reciprocal polarization rotators, and an optical bench. The laser may generate an optical signal that may be focused utilizing the microlens. The optical signal may be reflected at an angle defined by the turning mirror, and may be transmitted out of the light source arrangement to one or more grating couplers in the chip. The laser may include a feedback insensitive laser. The light source arrangement may include two electro-thermal interfaces between the optical bench, the laser, and a lid affixed to the optical bench. The turning mirror may be integrated in a lid affixed to the optical bench or may be integrated in the optical bench.

Abstract: A gyroscope includes a first optical resonator in optical communication with at least one optical waveguide and a second optical resonator in optical communication with the first optical resonator. One of the first optical resonator and the second optical resonator has a power loss rate L greater than zero and the other of the first optical resonator and the second optical resonator has a power gain rate G greater than zero. The at least one optical waveguide, the first optical resonator, and the second optical resonator are configured to be below lasing threshold. The gyroscope further includes at least one optical detector in optical communication with the at least one optical waveguide, and the at least one optical waveguide is configured to receive, from at least one light source, light having an input power Pin at a frequency ?p and to transmit at least a portion of the light having an output power Pout to the at least one optical detector.

Abstract: An optical phase modulating method of a multi-integrated optical circuit of an interferometric fiberoptic gyroscope with a control feedback control with a digital modulation and demodulations approach includes the step of modulating at eight modulation levels. Each modulation levels has a duration of one-quarter of a light propagation time in a fiberoptic coil.

Abstract: An optical gyroscope includes, in part, an optical switch, a pair of spiral optical rings and a pair of photodetectors. The optical switch supplies a laser beam. The first spiral optical ring delivers a first portion of the beam in a clockwise direction during the first half of a period, and a first portion of the beam in a counter clockwise direction during the second half of the period. The second spiral optical ring delivers a second portion of the beam in a counter clockwise direction during the first half of the period, and a second portion of the beam in a clockwise direction during the second half of the period. The first photodetector receives the beams delivered by the first and second optical rings during the first half of the period. The second photodetector receives the beams delivered by the first and second optical rings during the second half of the period.

Abstract: A resonator paradigm, where the resonator structure is made up of a very large number of small, coupled Coriolis sensitive units arranged in a periodic 1D or 2D (and, possibly, in the future, 3D) structure to create a Coriolis-sensitive fabric that supports a large number of Coriolis-coupled supermodes. Such a fabric can be shaped into arbitrary waveguides that propagate either pulses of excitation that are Coriolis-coupled, thus enabling an acoustic version of a FOG-type gyroscope (where a pulse of excitation travels along a passive waveguide and it's phase/time delay is measured), or support multiple stationary Coriolis-coupled vibration modes analogous to optical laser modes in an RLG where counter-propagating modes of oscillation are maintained at constant amplitude via a continuous addition of energy.

Abstract: A passive ring interferometer sensor includes an electromagnetic ring path configured to receive a pair of electromagnetic waves from an electromagnetic radiation source and to direct the waves to be counter-propagating within the ring path toward respective ends of the path. A combination junction receives the waves from the respective ends and combines the waves to be co-propagating within a coupling path. Polarization elements are configured to set the waves to be mutually co-polarized within the electromagnetic ring path and to be mutually cross-polarized within the coupling path. A detector is configured to receive the mutually cross-polarized waves from the coupling path and to detect second-order coherence. Embodiments can sense rotation rate as fiber-optic gyroscopes or serve as other types of sensors such as gravitational wave sensors. Embodiments may have greatly increased unambiguous range and decreased sensitivity to any centroid wavelength shift.

Abstract: Apparatus and methods demonstrate a chip-scale direct optical to RF link that frequency divides up to 120 GHz optical frequency combs to 10 GHz using harmonic multi-tone injection locking. The embodied invention links widely separated optical frequency combs in the millimeter wave regime (>120 GHz) or THz domain (100s of GHz to THz domain), e.g., microresonator-based frequency combs, which are currently outside of the photo-detection region, into the microwave domain (10s of GHz) where it can be easily photo-detected and controlled. The technique works as a perfect optical divider, using a mode-locked laser and optical injection locking as the technique to phase-lock both lasers.

Abstract: Apparatuses and methods for a four port atomic gyroscope are disclosed. Because of its four ports, a four port atomic gyroscope has an output separate from an input so as to increase sensitivity of the atomic gyroscope. Thus, smaller changes in rotation rate around a center axis of an optical waveguide loop of the four port atomic gyroscope can be detected.

Abstract: A hyperbolic modulation offset reducer circuit for a resonator fiber optic gyro (RFOG) is provided. The circuit includes a first demodulation circuit that is configured to demodulate a received transmission signal from a resonator at twice a sideband heterodyne detection modulation frequency to reject signals due to backscatter. A slave resonance tracking loop of the circuit is coupled to an output of the first demodulation circuit. The slave resonance tracking loop is configured to create an offset frequency signal from the transmission signal that is applied to an optical phase lock loop of a RFOG. A hyperbolic modulator offset control loop is also coupled to the output of the first demodulation circuit. The hyperbolic modulator offset control loop is configured to create a subharmonic common modulation signal from the transmission signal that is coupled to a common phase module in a silicon photonics chip of the RFOG.

Abstract: The present disclosure relates to system-level integration of lasers, electronics, integrated photonics-based optical components and a sensing chip. Novel waveguide design on the integrated photonics chip, acting as a front-end chip, ensures precise detection of phase change in a fiber coil or a sensing chip having a waveguide coil or ring resonator, where the sending chip is coupled to the front end chip. Strip waveguides are designed to primarily select TE mode over TM mode when laser light is coupled into the integrated photonics chip. A plurality of mode-selective filters, based on multi-mode interference (MMI) filter, a serpentine structure, or other types of waveguide-based mode-selective structure, are introduced in the system architecture. Additionally, implant regions are introduced around the waveguides and other optical components to block unwanted/stray light into the waveguides and optical signal leaking out of the waveguide.

Abstract: A vibration sensing optical fiber sensor is structured to include a probe light supplying section, an optical fiber, a polarimeter for reflected light, and a computing unit. The probe light supplying section generates, as probe light, light pulses that are switched alternately and periodically to orthogonal polarization directions. The probe light is inputted to the optical fiber. The polarimeter for reflected light measures a state of polarization of reflected light that is the probe light that has been reflected by the optical fiber. The computing unit carries out specifying of a position of vibrations by using the differential angular velocity from the state of polarization measured by the polarimeter for reflected light.

Abstract: A resonant fiber optic gyroscope comprises: a ring resonator including a fiber coil fabricated from a first type of hollow core fiber; a light source to produce at least two light beams, wherein a first light beam is configured to travel in a clockwise direction in the ring resonator and a second light beam is configured to travel in a counterclockwise direction in the ring resonator; a filter resonator assembly coupled between the light source and the ring resonator including: at least two short pieces of optical fiber shorter in length than the fiber coil, the at least two short pieces of optical fiber fabricated from the first type of hollow core fiber; and wherein prior to the beams entering the ring resonator, a plurality of reflective devices are configured to condition the beams such that they excite the fundamental mode of the hollow core fiber within the ring resonator.

Abstract: A resonator paradigm, where the resonator structure is made up of a very large number of small, coupled Coriolis sensitive units arranged in a periodic 1D or 2D (and, possibly, in the future, 3D) structure to create a Coriolis-sensitive “fabric” that supports a large number of Coriolis-coupled “supermodes. Such a “fabric” can be shaped into arbitrary “waveguides” that propagate either pulses of excitation that are Coriolis-coupled, thus enabling an acoustic version of a FOG-type gyroscope (where a pulse of excitation travels along a passive waveguide and it's phase/time delay is measured), or support multiple “stationary” Coriolis-coupled vibration modes analogous to optical laser modes in an RLG where counter-propagating modes of oscillation are maintained at constant amplitude via a continuous addition of energy.

Abstract: Provided is a polarization controller. The polarization controller includes a substrate, a first core disposed on the substrate and having a rectangular parallelepiped shape, a first cladding layer configured to cover the first core and the substrate and including a groove parallel to the first core in an edge of an upper end thereof, and a metal pattern disposed in the groove and including a first side surface and a bottom surface, which are adjacent to the first core.

Abstract: An imaging system uses polarized light to illuminate the target and then uses a polarization filter to remove the light that is reflected from the target without modification. The target can include one or more anisotropic objects that scatter the light and alter the polarization state of the reflected light and causing it to be selectively transmitted to the imaging device which can record the transmitted light through the filter. The illuminating light can be circularly polarized and the filter can remove the circularly polarized light. The target can include asymmetric nanoparticles, such as nanorods that alter the amplitude or phase of the scattered light enabling pass through the filter to be detected by the imaging device.

Abstract: An apparatus and a method for detecting rotation based on the Sagnac effect is disclosed. Input light having sufficient power is injected into a circulating optical resonator to thereby excite an optomechanical oscillation of the resonator at an instantaneous mechanical angular frequency. Rotation of the circulating optical resonator causes a change in a frequency of the optomechanical oscillation of the resonator, which in turn causes the instantaneous mechanical angular frequency to change. The optomechanical oscillation produces modulation sidebands in the resonating optical field at the instantaneous mechanical angular frequency and harmonics thereof, which are demodulated from the optical frequency by detection in a photodetector. Differences in the instantaneous mechanical angular frequency induced by rotation are detected by processing the photodetector output signal.

Abstract: Techniques and devices for optical sensing of rotation based on measurements and sensing of optical polarization or changes in optical polarization due to rotation without using optical interferometry.

Abstract: An optical fiber sensor system includes a light source, a modulation unit, an optical coupler, a polarization separator, a first polarization controller optically coupled to the polarization separator, and a first detection unit that includes a first optical detector that receives the first component, converts the first component into a first electrical signal, and detects stress. The first polarization controller controls a polarization state of light input to the polarization separator so that the first electrical signal exhibits a first-order response to the stress.

Abstract: Systems and methods for reducing polarization-related bias errors in RFOGS are described herein. In certain implementations, an RFOG system includes a fiber optic resonator, one or more laser sources, wherein light from the laser sources launches first and second optical beams into the fiber optic resonator in opposite directions, and an electro-optically tunable devices in the resonator path configured to modulate the phase difference between polarization components in the first and second optical beams as the optical beams propagate within the fiber optic resonator. The system further includes at least one photodetector, wherein the polarization components of the first and second optical beams are incident on the photodetector, wherein the at least one photodetector provides an electrical signal, and at least one processing unit configured to receive the electrical signal and calculate a rotation rate for the RFOG and provide a drive signal for the electro-optically tunable device.

Abstract: Methods and systems for a photonically enabled complementary metal-oxide semiconductor (CMOS) chip are disclosed. The CMOS chip may comprise a plurality of lasers, a microlens, a turning mirror, and an optical bench, and may generate optical signals utilizing the lasers, focus the optical signals utilizing the microlens, and reflect the optical signals at an angle defined by the turning mirror. The reflected optical signals may be transmitted into the photonically enabled CMOS chip, which may comprise a non-reciprocal polarization rotator, comprising a latching faraday rotator. The CMOS chip may comprise a reciprocal polarization rotator, which may comprise a half-wave plate comprising birefringent materials operably coupled to the optical bench. The turning mirror may be integrated in the optical bench and may reflect the optical signals to transmit through a lid operably coupled to the optical bench.

Abstract: An optical system is provided having a laser configured to generate light having a first laser spectrum with a first linewidth, a waveform generator configured to produce a noise waveform, and an electro-optic phase modulator in optical communication with the laser and in electrical communication with the waveform generator. The electro-optic phase modulator is configured to receive the light having the first laser spectrum, to receive the noise waveform, and to respond to the noise waveform by modulating the light to produce light having a second laser spectrum with a second linewidth broader than the first linewidth.

Abstract: Systems and methods for dynamic bias offset operation in RFOGs are provided. In certain embodiments, an RFOG system includes a fiber optic resonator; laser sources that launch first and second optical beams into the fiber optic resonator in opposite directions; a first servo loop configured to lock the first optical beam to a resonance frequency, the first servo loop including a modulator that modulates the first optical beam at a first resonant tracking frequency; a second servo loop configured to lock the second optical beam frequency, on average, to a resonance frequency, the second servo loop including a modulator that modulates the second optical beam at a second resonant tracking frequency, wherein the second optical beam is further modulated by a modulation frequency; and a filter configured to attenuate signals that result from the interference of the first and second optical beams.

Abstract: A sensor system provides measurement of building interstory drift based on a laser beam impinging on a discrete diode sensor array. The diode sensor array determines the location at which a projected laser bean strikes the array, which provides a direct measurement of interstory drift. The diode sensor array is a two dimensional array of discrete diodes that allow the location of an impinging laser beam to be very accurately tracked as the beam moves back-and-forth across the diode array. Local rotations of the laser source that result from rotations of structural members (e.g. floor beam rotation) are appropriately corrected for. This allows accurate, dynamic measurements of the interstory drift between two floor levels of a shaking building.

Abstract: In one embodiment, a method is provided. The method comprises generating a waveform; measuring signals representative of angular rotation rate in a linear region of the waveform; and diminishing bias error about at least one of a waveform's maxima and minima.

Abstract: Disclosed is an optical fiber interferometric system including a light source (1), a fiber optic coil (8), a coil splitter (3), a photodetector (2), and a polarization filtering unit. According to an embodiment, the polarization filtering unit includes a first waveguide polarizer (51), at least one second thin-plate polarizer (52) and an optical waveguide section (12), the at least one second polarizer (52) being disposed in the Rayleigh zone between a first waveguide end (21) of the first polarizer (51) and a second waveguide end (22) of the optical waveguide section (12).

Abstract: A system for detecting a structural change to a structure is provided, wherein an exciter is positioned at a first location of the structure to transmit an excitation signal that is based on a reference signal and to apply the excitation signal to the structure. An accelerometer is positioned at a second location of the structure to sense the excitation signal after it has propagated to the second location. The accelerometer outputs an electrical signal that represents seismic activity applied to the structure by the excitation signal. A signal processing component is synchronized with the reference signal and receives the electrical signal. The signal processing component is configured to use the reference signal to extract portions of the electrical signal that are synchronized with the reference signal, and to output phase and amplitude values of the extracted portion.

Abstract: A transmissive photonic crystal fiber ring resonator employing single optical beam-splitter comprises: a first fiber-optic collimator, a second fiber-optic collimator, a first photonic crystal fiber collimator, a second photonic crystal fiber collimator, an optical beam-splitter, and a fixture. The first fiber-optic collimator, the second fiber-optic collimator, the first photonic crystal fiber collimator, the second photonic crystal fiber collimator, and the optical beam-splitter are fixed on the fixture; the fiber pigtails of the first fiber-optic collimator and the second fiber-optic collimator are the input/output ports; the fiber pigtails of the first photonic crystal fiber collimator and the second photonic crystal fiber collimator are connected.

Abstract: A bidirectional optical transmission apparatus includes a first optical waveguide device, a second optical waveguide device, and a polarization-maintaining optical fiber that connects the first optical waveguide device and the second optical waveguide device. A direction of a slow axis of the polarization-maintaining optical fiber with respect to a first substrate at a connecting portion between the first optical waveguide device and the polarization-maintaining optical fiber and a direction of the slow axis of the polarization-maintaining optical fiber with respect to the second substrate at a connecting portion between the second optical waveguide device and the polarization-maintaining optical fiber are substantially orthogonal to each other.

Abstract: In some examples, an accelerometer may self-calibrate while in use by setting a scale factor of the accelerometer to a first value; while the scale factor of the accelerometer is set to the first value, obtaining a first acceleration value; setting the scale factor of the accelerometer to a second value; while the scale factor of the accelerometer is set to the second value, obtaining a second acceleration value; based on the first acceleration value and the second acceleration value, determining a bias correction value; obtaining a third acceleration value; and correcting the third acceleration value based on the bias correction value.

Abstract: Techniques and devices for optical sensing of rotation based on measurements and sensing of optical polarization or changes in optical polarization due to rotation without using optical interferometry. In implementations, a device for optical sensing of rotation can include a detection device that includes: (1) a beam splitter that splits the optical output into four optical beams; (2) four detection modules that receive the four optical beams, respectively, to obtain measurements of four different optical Stokes parameters from the four optical beams, respectively, and (3) a processing unit that processes the measurements of four different optical Stokes parameters to determine a rotation angle of a state of polarization of the optical output and a differential phase shift between the first and the second optical beams caused by a rotation experienced by the optical loop.

Abstract: Advantageously, at least one embodiment comprises a flexible pitch reducing optical fiber array (PROFA) coupler capable of maintaining all channels discretely with sufficiently low crosstalk, while providing enough flexibility to accommodate low profile packaging, and having increased stability with respect to environmental fluctuations, including temperature variations and mechanical shock and vibration, and that is combinable in multiple quantities thereof to form an optical multi-port input/output (IO) interface.

Abstract: Embodiments are provided for an improved 2×1 switch cell design with integrated photodiode for off-state monitoring. In an embodiment, am optical switch comprises a 2×1 multi-mode interferometer (MMI) coupler including two input waveguides jointly coupled to an output waveguide, and a photodetector coupled to an edge of a first waveguide of the input waveguides, and positioned next to a side of the output waveguide. In another embodiment, an optical chip comprises two input waveguides parallel to each other, and an output waveguide coupled to the two input waveguides. The optical chip further includes a photodetector coupled to a first waveguide of the two input waveguides, and positioned next to the output waveguide, and a branch waveguide extending from the first waveguide into the photodetector.

Abstract: A signal processing apparatus includes: a clock generator configured to generate a clock signal having a phase based on a phase of an input signal; a phase modulator configured to shift the phase of the clock signal to generate a phase-shifted clock signal; and a signal synthesizer configured to synthesize the phase-shifted clock signal and the input signal to generate a synthesized signal, wherein the phase modulator is configured to determine a value by which to shift the phase of the clock signal based on an amplitude of the input signal and an amplitude of noise included in the input signal.

Abstract: The invention relates to an integrated optical coupler (1) comprising a substrate (3), at least two planar waveguides (4), which are arranged on or in the substrate (3) and consist of a material having a virtually isotropic refractive index (anisotropy of the refractive index of less than 10?6), and al least three monomode fibers (8, 9, 10) coupled to the planar waveguides (4). One of the monomode fibers (8) is a polarization-maintaining fiber. A fiber optic system according to the invention comprises an integrated optical coupler (1) according to the invention, a light source (21) that is suitable for generating light beams, and a first pigtail fiber (22), which is connected at one end to the light source (21) and at the other end to the polarization-maintaining fiber (8) of the integrated optical coupler (1).

Abstract: The present invention provides an angular velocity detection method adopting a bi-directional full reciprocal coupling optoelectronic oscillator, which is implemented on an optical carrier microwave gyroscope. The optical carrier microwave gyroscope is a bi-directional resonant optical carrier microwave angular velocity measurement device sharing one optical fiber loop. The core of the method lies in that the Sagnac effect is sensed using a bi-directional optical carrier microwave resonant cavity, where the optical carrier microwave resonant cavity employs a coupling optoelectronic oscillator to achieve a bi-directional full reciprocal optical fiber path, and non-reciprocity error of the resonant cavity is eliminated effectively. The angular velocity detection method has features of high-precision, easy implementation and low costs.

Abstract: A fiber optic gyroscope (FOG) is provided. The FOG comprises a depolarizer that receives light from a light source, a multifunction integrated optic chip (MIOC) and a sensing coil coupled to outputs of the MIOC. The FOG also includes a polarizer coupled between an output of the depolarizer and an input of the MIOC. The polarizer mitigates polarization non-reciprocity (PNR) bias error and enhances the polarization extinction ratio (PER) of the FOG.

Abstract: A fiber-optic Sagnac interferometer in a rotation rate sensor comprises a multifunctional integrated optical chip (MIOC) with a MIOC transfer function. A digital filter is connected upstream to the multi-functional integrated optical chip, whose filter transfer function corresponds basically to the inverse MIOC transfer function such that the MIOC transfer function is compensated by the filter transfer function. Corresponding coefficients of the filter transfer function may be determined in a main control loop.

Abstract: A fiber optic interferometric measurement system includes a light source; first and second optical transmission elements; first and second Sagnac-ring interferometers, respectively, including first and second fiber optic coils, and, respectively, having lengths L1 and L2; and first and second individual integrated optical circuits, respectively, connected to the first and second optical transmission elements, and to the two ends of the first and second optic coils, respectively. The interferometric system includes a multiple integrated optical circuit integrating, on a single substrate, the first and second individual integrated optical circuits, and the difference ?l between the optical length of the first optical transmission elements and the optical length of the second optical transmission elements is higher than the maximum of ?Nb1×L1 and ?NB2×L2, in which ?Nb1 and ?Nb2, respectively, are the group birefringence index difference of the first and second fiber optic coils, respectively.

Abstract: This invention revealed and demonstrated a method of measuring and deriving a Jones Matrix of a fiber or fiber component, and to compensate the fiber or fiber component such that the fiber or fiber component plus the compensated optical circuit act as if an Unitary Matrix free space condition. In this way, all compensated fibers or fiber components act the same no matter what their original conditions are. It greatly enhances the fiber or fiber component repeatability and stability throughout the fiber or fiber component production line. The compensated circuit for Unitary Matrix can be applied externally or internally.