22 results about "Fiber loop" patented technology

The utility model provides a kind of optical fiber optical tweezers fluorescence lifetime detection equipment, by the light beam emitted by light source is divided into two ways, using the first optical fiber coupler to the two-way light signal received is coupled, and the light signal after coupling is transmitted to the optical fiber circulator connected, transmission to displacement control assembly by optical fiber circulator. Displacement control assembly utilizes one-way light signal to carry out target micro-particle capture, utilizes another light beam corresponding light signal to excite target micro-particle to generate excitation fluorescence signal, utilizes detection assembly to carry out photon number detection to excitation fluorescence signal, determines the fluorescence lifetime of target micro-particle. The utility model equipment can be realized in flexible control micro-particle, and the fluorescence lifetime of micro-particle is detected, and the utility model is more simple and efficient, applicable to precision large instrument to carry out ultrafast signal detection.

The application discloses a Stokes parameter encoder, which comprises a fiber optical circulator and an optical path round trip path; a polarization maintaining fiber Faraday rotator is arranged on the optical path round trip path to rotate the polarization of light by 45 degrees; the fiber optical circulator is a polarization maintaining fiber optical circulator; the fiber optical polarization beam splitter is a polarization maintaining fiber optical polarization beam splitter; the delay fiber is a polarization maintaining delay fiber; and the fiber optical phase modulator is a polarization maintaining fiber optical phase modulator. The application further discloses a parameter encoding method of the encoder. The above technical scheme can perfectly offset the rotation angle deviation problem caused by the device, can guarantee the stability of the rotation angle regardless of the angle deviation of the device, is easy to realize the driving circuit, is easy to integrate and small in size due to the pure fiber structure, and can realize the continuous variable quantum key distribution of the complete GG02 protocol based on the Stokes encoder.

This application provides an optical fiber sensing system, its calibration method, and a storage medium, relating to the field of optical fiber sensing technology, to improve the dynamic range of the optical fiber sensing system. The optical fiber sensing system includes a signal generator, an optical fiber circulator, a reference optical fiber, a single-photon detector, a processor, and a sensing optical fiber. The signal generator, reference optical fiber, and single-photon detector are respectively connected to the optical fiber circulator. The sensing optical fiber is connected to the reference optical fiber. The single-photon detector is used to acquire a first reference measurement signal and a second reference measurement signal. The first reference measurement signal has attenuation compared to the second reference measurement signal. The processor is used to determine a dead time based on the first reference measurement signal, the second reference measurement signal, and the attenuation coefficient corresponding to the attenuation. The single-photon detector is also used to acquire sensing measurement signals. The processor is also used to calibrate the sensing measurement signals based on the dead time. This optical fiber sensing system is used to detect the state of a target.

The application provides a distributed optical fiber acoustic wave sensing system and a pattern recognition method. The application relates to the fields of optical fiber sensing and pattern recognition, and the system comprises the following steps: continuous coherent light emitted by a narrow-line-width laser is split into two paths by a beam splitting fiber coupler, one path is used as local reference light, and the other path is used as probe light; the probe light is modulated into optical pulses in an acousto-optic modulator driven by a waveform generator, and the optical pulses are injected into a measured sensing optical fiber through a fiber loop; Rayleigh backscattering light returned through the measured sensing optical fiber is mixed with the local reference light through the fiber loop, and the mixed light is decomposed into two orthogonal polarized light beams in a polarization beam splitter and is transmitted to a first balanced photodetector and a second balanced photodetector respectively to be converted into electrical signals; and the two orthogonal interference electrical signals are synchronously collected by a data acquisition card and are sent to a host computer for demodulation. The application provides a new distributed acoustic wave monitoring method with high reliability and high generalization ability, and has extremely high engineering popularization value.

This invention discloses a fiber optic deformation sensor and deformation measurement method based on Sagnac interferometry. The sensor includes a Sagnac interferometer optical path and a photoelectric conversion module. The Sagnac interferometer optical path includes a sensing fiber loop, which includes at least one segment of polarization-maintaining fiber. The polarization-maintaining fiber has an axially stretchable elastic helical structure. The interference light intensity output by the Sagnac interferometer optical path changes monotonically with the axial stretch of the polarization-maintaining fiber. The photoelectric conversion module receives the interference light intensity and converts it into an electrical signal. This invention achieves wide-range deformation measurement while maintaining high sensitivity by setting the polarization-maintaining fiber as an axially stretchable elastic helical structure. It uses an intensity modulation method to directly convert the signal into an electrical signal through a photodetector, eliminating the need for a spectrometer, significantly reducing system cost. Furthermore, the structure is simple and easy to fabricate, making it widely applicable to various high-precision, large-deformation real-time monitoring scenarios.

The application provides a fiber ring temperature performance testing device, which comprises a high-low temperature box and a constant temperature box. The high-low temperature box is internally provided with a rotatable first turntable, and the constant temperature box is internally provided with a rotatable second turntable. The second turntable is used for placing a test host. A transmission central shaft assembly is connected between the first turntable and the second turntable, so that the first turntable and the second turntable synchronously rotate. The first turntable is provided with a fiber ring support, and the fiber ring support is used for placing a measured fiber ring. The first turntable is further provided with an isolation cover for buckling the measured fiber ring. The problem that the test system itself is affected by temperature and is wound dry, thereby affecting the test precision, is solved.

This invention discloses a lightweight, compact, three-axis integrated fiber optic inertial navigation device, belonging to the field of inertial navigation technology. Specifically, it relates to a lightweight, compact, three-axis integrated fiber optic inertial navigation device, comprising a housing, an inertial measurement unit (IMU), a magnetic shielding plate, and navigation control circuit components. The IMU includes three orthogonally arranged accelerometers, three orthogonally arranged fiber optic loop components, and an SLD (Single-Loop Light Source). The three fiber optic loop components share a single SLD light source, forming a three-axis integrated fiber optic gyroscope. The fiber optic loop components include a loop support, a 260m polarization-maintaining fiber optic loop, and a magnetic shield. The magnetic shield is fixed to the lower end face of the loop support, forming a closed magnetic shielding environment. The 260m polarization-maintaining fiber optic loop is located within this closed magnetic shielding environment. This invention optimizes the design of the IMU and navigation control circuit components of the fiber optic inertial navigation system, achieving magnetic shielding isolation of the fiber optic loop and physical isolation of heat-generating devices while reducing system weight and volume, thereby improving the stability of the navigation system.

This invention provides a large-scale, high-precision optical Ising computer that can significantly increase the number of spins, achieve optimal binary bifurcation for the problem to be solved using an arbitrary nonlinear function, and converge stably and quickly. [Solution] The system includes a pulse light source 1, an optical fiber loop 3 into which optical pulses from the pulse light source 1 are introduced, an erbium-doped optical fiber amplifier 4 provided within the optical fiber loop 3, a homodyne detection circuit 5 for detecting optical pulses from the optical fiber loop 3, a matrix-nonlinear calculation circuit 6 for digitally calculating an interaction function and a nonlinear function for binary branching for the optical pulses detected by the homodyne detection circuit 5, and an AM optical modulator 2 which receives the optical pulses from the pulse light source 1 and the information obtained from the digital calculations of the matrix-nonlinear calculation circuit 6, modulates the input optical pulses, and then injects them into the optical fiber loop 3.

This application discloses a method, apparatus, device, and medium for measuring temperature along an optical fiber. The method includes: acquiring the actual optical power of the anti-Stokes light in the optical fiber loop and the difference function of the actual optical fiber transmission loss coefficient of the anti-Stokes light at each scattering point in the optical fiber; for any scattering point in the optical fiber, determining the actual ambient temperature of the scattering point based on the difference function of the actual optical power of the anti-Stokes light in the optical fiber loop and the actual optical fiber transmission loss coefficient of the anti-Stokes light; and determining the actual ambient temperature of the optical fiber based on the actual ambient temperatures of each scattering point in the optical fiber. In this application, the actual optical power of the anti-Stokes light in the optical fiber loop at the scattering point is obtained by filtering the optical power of Rayleigh scattered light included in the optical power measurement data of the anti-Stokes light at the scattering point, thereby improving the signal-to-noise ratio of the anti-Stokes light signal and thus improving the accuracy of temperature measurement along the optical fiber.

This invention provides a Sagnac-type soil moisture monitoring method based on hollow-core photonic crystal fiber. It utilizes a moisture-sensitive material injected into the hollow-core photonic crystal fiber, employs a Sagnac interference structure, and leverages phase modulation and intrinsic frequency tracking to achieve high-precision measurement and efficient moisture inversion. The method includes the following steps: injecting moisture-sensitive material into the hollow channel of the hollow-core photonic crystal fiber; splitting the light source signal into two beams via a broadband light source through a second fiber coupler; one beam undergoes polarization filtering through a fiber polarizer before entering a first coupler, with the two ends of the first coupler coupled to the two ends of the hollow-core photonic crystal fiber to form a closed fiber loop; the other beam directly enters the fiber loop; a phase modulator is added to one arm of the first coupler, with the modulation frequency matched to the intrinsic frequency of the hollow fiber; the adjustment amount Δf of the phase modulator frequency is measured, and the soil moisture is calculated using Δf.

The present application relates to the technical field of optical fiber communication, and particularly relates to a kind of multi-fiber multi-wavelength optical fiber data processing method, and when writing, address is allocated to electrical data signal and is packaged as optical data frame, is stored in optical fiber storage unit after electro-optical conversion, wavelength division multiplexing, branching, routing, predetermined mapping table is stored mapping relationship;When reading, target single-channel multi-wavelength optical signal is read out in the set time window, and after photoelectric conversion, frame header identification is parsed and compared with predetermined mapping table Data check, output data after check, abnormal triggers re-reading;When erasing, target optical signal loop cycle is terminated, and the corresponding mapping relationship in predetermined mapping table is deleted.The present application also relates to a kind of multi-fiber multi-wavelength optical fiber data storage system and storage medium for data center.The present application realizes the parallel storage of multi-wavelength optical signal in optical fiber loop, effectively improves the storage density of optical fiber loop, data reading accuracy and system resource utilization, and is suitable for high-speed large-capacity optical cache storage scene.

The application discloses a low-stress fiber loop design method based on finite element simulation and belongs to the technical field of computer-aided design. The low-stress fiber loop design method of the application is aimed at the jump-turn transition area of an octupole symmetrical winding method fiber loop, constructs a jump-turn geometric model containing cross-layer jump-turn optical fibers and regular layer winding optical fibers, establishes a local Cartesian coordinate system and adopts a sweeping method to perform structured grid division, applies a fixed constraint to the regular layer winding optical fibers, applies tension and opposite displacement loads to the cross-layer jump-turn optical fibers to simulate jump-turn deformation, considers the nonlinear mechanical behavior of the optical fibers, solves equivalent stress distribution by adopting a nonlinear finite element algorithm, obtains an optimal transition path based on the equivalent stress distribution fitting, and adjusts the jump-turn angle and wrapping buffer materials. The application can truly restore the local stress state under the jump-turn scene, effectively reduces the stress concentration of the jump-turn transition area, and improves the design reliability and mechanical stability of the fiber loop.

The application provides a kind of fiber loop scale factor testing method based on distributed optical testing, belongs to optical measurement and optical fiber sensing technical field.The method: using optical frequency domain reflectometer to test fiber loop under normal temperature and fast temperature change, then the test signals under two different temperature states are self-correlated and cross-correlated demodulated, realize temperature / strain decoupling, peel off the distributed temperature parameters of fiber loop, then the distributed strain parameters are substituted into scale factor calculation formula, then the scale factor values of fiber loop under fast temperature change can be obtained by accumulating the calculated scale factor along the length.The application can realize the quantitative measurement of scale factor of fiber optic gyroscope sensitive ring under fast temperature change, and the scale factor of fiber optic gyroscope sensitive ring is the core to ensure the angular velocity-signal conversion accuracy of gyro system, directly determines the reliability of linear mapping relationship between gyro output and actual rotation input, and plays an important role in the winding process optimization of fiber optic gyroscope sensitive ring.

Embodiments of the present application relate to the field of quantum ranging positioning, and in particular to an automatic tracking ranging positioning system based on quantum entangled signals. A specific embodiment of the system comprises: a quantum entangled light source outputs an entangled photon pair as a reference light beam and a signal light beam; the reference light beam is transmitted into a time-to-digital converter; the signal light beam is transmitted into a first input-output port of a fiber-optic circulator; the signal light beam is transmitted into a beam transceiver; the signal light beam is transmitted to an angle reflector at a target point to be measured, and the reflected signal light beam is transmitted into the fiber-optic circulator; the reflected signal light beam is transmitted into a second photon detector; the reflected signal light beam is transmitted into a time-to-digital converter; the arrival time sequences of reference photons and signal photons corresponding to the reference light beam and the reflected signal light beam, respectively, are detected; and based on the arrival time sequences of the reference photons and the signal photons, target point coordinate information of the target point to be measured is determined. This embodiment can realize the functions of automatic tracking and rapid ranging positioning of a moving target.

This invention discloses a high-precision fiber optic vibrometer suitable for detecting minute signals in confined spaces. It utilizes a lens-fiber optic probe and zero-difference interferometry to collect and process reflected signals, thus achieving a high-precision fiber optic vibrometer suitable for detecting minute vibrations in confined spaces. Based on a 100-micron-level lens-fiber optic probe, it penetrates deep into confined spaces to collect minute reflected light signals. Using a fiber optic circulator and zero-difference interferometry, the reflected light signals are extracted and processed. Based on the processed reflected signals, the amplitude of minute vibrations in the confined space is deduced. This invention has the advantages of resistance to environmental interference, high spatial resolution, and high detection sensitivity, with a displacement detection sensitivity of less than 5 pm·Hz. ‑1 / 2 It is applicable to vibration detection in various environments, especially for detecting minute vibrations in confined spaces.

This invention relates to a high-fidelity optical pulse signal cyclic replication device, belonging to the field of optical communication. The device includes a 2×2 3dB fiber coupler, a 1×2 3dB fiber coupler, a high-speed optical switch, an optical switch drive control board, an optical isolator, a 1×2 fiber coupler, a fiber circulator, an electrically controlled delay line, a delay fiber, a reflector, a fiber amplifier, and a chassis. The coupling ratio of the 1×2 fiber coupler is 10% / 90%. This invention employs a fiber amplifier to compensate for insertion loss in the fiber loop, theoretically ensuring equal amplitude output. A high-speed optical switch is used to solve the problem of excessive noise accumulation after multiple replications, effectively zeroing loop noise. A narrowband optical filter is used to effectively suppress noise in the loop. Simultaneously, a high-reflectivity reflector is used to form a reflective structure, making the delay time twice that of unidirectional transmission.

This invention discloses a method for measuring gravity gradient based on an elastic beam. The steps include: constructing two identical measurement units, each unit comprising an angle measuring instrument, an elastic beam, and a mass block. The mass block is positioned at the tail end of the elastic beam, and the fiber optic loop of the angle measuring instrument is positioned on the mass block. The mass of the elastic beam is much smaller than the mass of the mass block. When measuring the diagonal component Γ in the i-direction of the gravity gradient... ii During measurement, the first ends of the two elastic beams are fixedly connected to a base, and the elastic beams in the two measuring units are placed parallel and symmetrically along the i-direction; the distance between the two mass blocks and the axis of symmetry is h; then the diagonal component Γ is calculated using the formula. ii When performing the off-diagonal component Γ in the gravity gradient ji During measurement, the elastic beams in the two measurement units are placed end to end along the j direction.

The application belongs to the technical field of laser radar, and discloses a parallel linear frequency modulation continuous wave laser radar ranging and velocity measuring system, wherein laser of different wavelengths is emitted by a narrow linewidth single frequency fiber laser array, enters an electro-optic modulator after passing through a wavelength division multiplexer, and laser carrier output after passing through a fiber coupler is modulated by an arbitrary waveform generator and a microwave amplifier through the electro-optic modulator; the modulated light is divided into two beams of light by a beam splitter, one is a local oscillation light, and the other is a detection light; the detection light enters a fiber loop after power amplification by an EDFA amplifier, is emitted to an object after dispersion by a three-prism, and the reflected detection light enters the loop after entering the three-prism, mixes with the local oscillation light to enter a fiber coupler, and the light after the wavelength division multiplexer is obtained by a photoelectric detector to obtain an intermediate frequency signal, and then real-time N-way parallel fast Fourier transform is carried out to realize N-way distance and speed synchronous measurement. The application improves laser radar data acquisition rate and image refresh rate, and expands the field of view angle of the laser radar.

Optical fiber management assemblies. The assemblies can be installed in telecommunications equipment, such as telecommunications closures. The assemblies include parts with multiple features unitarily integrated therewith, minimizing the number of parts needed to manufacture, process, and put together the assembly. In some embodiments, the assemblies are adjustable in size depending on fiber management needs.

The application provides a stress detection-based fiber ring cracking defect detection method, which utilizes distributed Brillouin sensing technology to obtain the strain distribution of the fiber ring along the length direction, compares the stress difference between the healthy state and the current state, identifies the local stress anomaly caused by micro-cracks or structural damage, and realizes early discovery, accurate positioning and risk assessment of the cracking defect. The method has the advantages of non-destructive, high sensitivity, full distribution, quantification and the like, is suitable for quality control and reliability guarantee of high-precision fiber devices, and has important engineering application value.

This invention provides a capillary-based fiber optic biosensor and its fabrication method, belonging to the field of fiber optic sensing technology. The capillary-based fiber optic biosensor of this invention includes a fiber optic sensing unit, a peristaltic pump power module 2, a sample cell 3, a transmission fiber optic cable 5, a computer module 6, a signal acquisition and processing module 7, a fiber optic circulator 8, a light source module 9, and a waste liquid treatment module 10. The fiber optic sensing unit includes a fiber optic probe 4 and a capillary; wherein the direction of light signal transmission received or reflected by the fiber optic probe 4 is perpendicular to the length direction of the capillary, the fiber end face of the fiber optic probe 4 is parallel to the length direction of the capillary, and the fiber end face of the fiber optic probe 4 does not contact the capillary. The capillary-based fiber optic biosensor provided by this invention is a non-contact fiber optic biosensor, which facilitates disassembly and replacement of the capillary for reuse, thus helping to reduce manufacturing and monitoring costs.