24 results about "Fiber interferometer" patented technology

The utility model is suitable for the technical field of optical fiber sensing, and relates to a double-interferometer push-pull and common-mode noise differential suppression optical fiber hydrophone, which comprises a first thin-wall cylinder, a second thin-wall cylinder, a first optical fiber interferometer and a second optical fiber interferometer, the first thin-wall cylinder is embedded in the second thin-wall cylinder, a first optical fiber winding area and a second optical fiber winding area are arranged on the first thin-wall cylinder, and a third optical fiber winding area and a fourth optical fiber winding area are arranged on the second thin-wall cylinder; the first optical fiber interferometer comprises a first short-arm sensing optical fiber, a first long-arm sensing optical fiber, a first Faraday rotating mirror and a second Faraday rotating mirror, and the second optical fiber interferometer comprises a second short-arm sensing optical fiber, a second long-arm sensing optical fiber, a third Faraday rotating mirror and a fourth Faraday rotating mirror. According to the utility model, the dual-push-pull structure is formed by the dual-fiber interferometer, so that temperature drift noise and optical scattering noise caused by the ultra-long sensing fiber are reduced, and common-mode noise formed by light source vibration, transmission optical cable jitter and the like is suppressed.

The application discloses an optical phase control method and system of an interference system, and relates to the technical field of optical phase, and solves the problems of poor control timeliness, large error and difficulty in considering convergence speed and steady-state jitter of the existing optical phase control technology. The application discloses an optical phase control method, which initializes a control quantity and a control parameter according to a target reference value of an optical phase; initializes a disturbance frequency, a block correlation quantity; inputs a driving voltage to a phase actuator, and collects a detection voltage signal; updates an error quantity, a cost quantity and the disturbance amplitude; judges whether the control parameter is a current control parameter according to the error quantity; updates the control quantity, and completes the control of the optical phase u n . The application discloses an optical phase control system, which comprises a microcontroller MCU, a DAC digital-analog conversion module, a phase actuator, an optical detection module and an ADC analog-digital conversion module. The application is suitable for the fields of phase stabilization such as fiber interferometer, phase modulation / compensation and coherent detection.

The invention discloses an arbitrary wave band frequency stabilization device based on double interferometers, and the device comprises a double-fiber interferometer module which is used for generating an interference signal related to the temperature and frequency changes; the temperature control module is used for carrying out temperature control on the dual-interferometer module; the control module is used for receiving the interference signal and outputting a control instruction according to the interference signal; wherein the double-interferometer module comprises an equal-arm interferometer and an unequal-arm interferometer; the equal-arm interferometer is used for responding to temperature change and outputting a first interference signal; the unequal-arm interferometer is used for responding to the frequency change and outputting a second interference signal; the control module receives the first interference signal and outputs a first control instruction to the temperature control module so as to improve the temperature control precision; and the control module receives the second interference signal and outputs a second control instruction to the laser so as to adjust the frequency of the laser. According to the device, the frequency of the laser can be kept stable and continuously tunable while the cost is effectively reduced.

The invention discloses an optical fiber interferometer, and relates to the technical field of polarization sensitive optical coherence tomography. According to the optical fiber interferometer, through modular structural design and precise parameter limitation, a compact framework formed by sequentially coupling and connecting the polarization unit, the polarization-maintaining coupler, the first polarization light splitting unit and the second polarization light splitting unit is constructed. The input end of the polarization-maintaining coupler is respectively coupled and connected with the input ends of the first polarization-maintaining optical fiber and the first single-mode optical fiber, the output end of the polarization-maintaining coupler is respectively coupled and connected with the input ends of the second polarization-maintaining optical fiber and the third polarization-maintaining optical fiber, and the included angle between the optical axis of the polarization-maintaining coupler and the optical axes of various optical fibers and the light splitting proportion of the polarization-maintaining coupler are strictly limited; the second polarized light and the third polarized light are orthogonal to each other, the fourth polarized light and the fifth polarized light are orthogonal to each other, the physical properties of the second polarized light and the fourth polarized light are consistent, and the physical properties of the third polarized light and the fifth polarized light are consistent.

The invention relates to an interrogator system for interrogating fiber based sensors. The system comprises a broadband excitation light source illuminating a first lead fiber section having a wavelength shift response generating optical waveguide sensor, and a second lead fiber section having an in-line two reflectors based fiber interferometer sensor. The system also includes a detection 3 x 3 interferometer having an optical path difference arranged to match the wavelength shift response generating optical waveguide sensor and the in-line two reflectors based fiber interferometer sensor.

The application discloses a kind of asymmetric laser interferometer type long-distance detection demodulation system and disturbance positioning method, including two lasers, Mach-Zehnder fiber interferometer, data acquisition card and industrial computer, two lasers provide the narrow linewidth light source of different central wavelength;Two light sources enter Mach-Zehnder fiber interferometer in clockwise and counterclockwise direction respectively, two signal lights share the same sensing fiber link when detecting;A phase modulator introduces high-frequency carrier signal on a sensing fiber, and the corresponding sensing light signal is modulated with high-frequency carrier;Subsequently two sensing interference light signals enter industrial computer after erbium-doped fiber amplifier, dense wave division multiplexer, photodetector, data acquisition card, two interference sensing light signals are demodulated into phase information introduced by disturbance event by corresponding improved phase generation carrier algorithm respectively, and the specific position information of disturbance event acting on fiber link is analyzed by cross-correlation time delay estimation theory.

The invention discloses a narrow linewidth optical fiber interferometer laser system and method based on a spread spectrum technology, and belongs to the technical field of optical fiber communication. The narrow linewidth optical fiber interferometer laser system comprises a laser, a first acousto-optic modulator, a first coupler, a second acousto-optic modulator, an optical loop device, a second coupler, a detection frequency mixing module and a power divider. According to the invention, low noise of a narrow linewidth optical fiber interferometer laser system is realized by using the structure of a circulating optical fiber loop, and the influence of higher harmonics of radio frequency signals and optical fiber reflection on the performance of the system is eliminated through spread spectrum driving signals applied to the second acousto-optic modulator. A narrow linewidth optical fiber interferometer laser system with low additional noise and high robustness is realized.

The invention discloses a management device for a quantum key distribution (QKD) system and a quantum communication system, and relates to the technical field of quantum communication, the management device for the QKD system comprises a light intensity management module and a spectrum management module, the light intensity management module at least comprises a first light intensity manager and a second light intensity manager, and the spectrum management module comprises a spectrum management module. The first light intensity manager comprises a first optical switch, a first optical fiber interferometer, a first variable optical attenuator, a first intensity modulator and a first light beam combiner, and the second light intensity manager comprises a second optical switch, a second optical fiber interferometer, a second variable optical attenuator, a second intensity modulator and a second light beam combiner. The first light intensity manager is respectively connected with the transmitting end of the QKD system and the spectrum management module, and the second light intensity manager is respectively connected with the transmitting end of the QKD system and the spectrum management module; and the spectrum management module comprises a dispersion compensation module, a filter and a plurality of wavelength division multiplexers, so that the complexity of light path construction is reduced, and integration is facilitated.

The invention discloses an optical fiber interferometer precision adjustment vibration reduction platform for plasma density diagnosis, and belongs to the technical field of magnetic confinement nuclear fusion plasma diagnos.The optical fiber interferometer precision adjustment vibration reduction platform comprises symmetrically-arranged vibration reduction bases, supporting columns are arranged above the vibration reduction bases, a cross beam is arranged above the supporting columns, and the cross beam is arranged above the vibration reduction bases. Cantilever supports are symmetrically arranged on the lower surface of the cross beam, cylindrical coil fixers are arranged on the peripheries of the cantilever supports, Helmholtz coils are arranged on the cylindrical coil fixers, L-shaped collimator fixers are arranged on the cantilever supports, and optical fiber interferometer collimators are arranged on the L-shaped collimator fixers; according to the optical fiber interferometer precision adjustment vibration reduction platform for plasma density diagnosis, environment vibration can be effectively restrained, it is ensured that the optical fiber interferometer reaches the theoretical phase resolution, precision height adjustment and firm locking can be achieved, and the accuracy and reliability of plasma density measurement data are guaranteed.

This invention provides a method based on MXene Ti 3 C 2 T x All-optical phase modulation device and modulation method for PDMS. This all-optical phase modulation device consists of a fiber interferometer and MXene Ti... 3 C 2 T x Two-dimensional materials, PDMS material composition, MXene Ti 3 C 2 T x Two-dimensional material was deposited onto the surface of coreless fiber II of the fiber interferometer. The surfaces of coreless fibers I and II of the fiber interferometer were also coated with PDMS material to complete the fabrication of an all-optical phase modulator. Based on MXene Ti... 3 C 2 T x The high photothermal conversion efficiency of two-dimensional materials and the high thermo-optical coefficient of PDMS material convert changes in excitation light into changes in the refractive index of PDMS material. The fiber optic interferometer senses the refractive index change of PDMS material, causing wavelength shift and phase change in the output interference spectrum. This invention optimizes the sensitivity of phase modulation, reduces device size, and enhances device reliability and practicality.

The application discloses a kind of narrow line width fiber laser systems based on active phase compensation of fiber loop interferometer frequency stabilization, comprising: fiber laser, the laser is sequentially connected with first frequency shifter, Y type coupler, X type coupler and photoelectric detector by conducting optical fiber and constitutes loop interferometer loop.The photoelectric detector is connected with radio frequency power divider, and also be used to convert beat frequency optical signal output by fiber loop interference loop into radio frequency electric signal;The output end of the radio frequency power divider is respectively connected with first feedback calibration loop and second feedback calibration loop, to carry out the fast feedback calibration of laser frequency by first feedback calibration loop, and carry out the active compensation of delay optical fiber phase noise by second feedback calibration loop.And by second proportional integral amplifier for slow feedback calibration of laser frequency.The interferometer frequency stabilization system presented in the application has high detection sensitivity and large bandwidth, and has lower environmental sensitivity.

The invention relates to an fiber interferometer measurement system for measuring a change in a fiber length. The system comprises a broadband type excitation light source, and a lead fiber provided with a pair of integrated optical reflectors with overlapping reflection spectrum, such as FBGs, defining a sensing fiber section therebetween having a variable fiber length. The lead fiber is associated with the excitation light source for being illuminated by said excitation light source. Further, the system comprises a detection 3 x 3 interferometer associated with the lead fiber for converting light received from the pair of integrated optical reflectors into an interferometric signal.

The invention relates to the technical field of optical fiber monitoring, in particular to a tunable optical fiber laser and an all-optical fiber micro-seismic monitoring system.The tunable optical fiber laser comprises a multi-wavelength active DFB phase shift grating packaging block, a first WDM, a first isolator, a second WDM, an erbium-doped gain optical fiber, a pumping source, a first optical fiber coupler, a second isolator, a DWDM, a plurality of optical splitters and a plurality of second optical fiber couplers; the all-fiber micro-seismic monitoring system comprises a tunable fiber laser, a fiber interferometer sensor, a photoelectric amplification conversion circuit, a data acquisition circuit, a main control board and a host terminal. Based on a tunable narrow linewidth laser structure formed by active DFB phase shift grating packaging blocks connected in series with multiple wavelengths and a pumping source, the application of a high-power multi-channel micro-seismic sensor can be met by only adopting a one-time excitation and one-time amplification structure; according to the all-fiber micro-seismic monitoring system, the tunable fiber laser light source and the fiber interferometer sensor are adopted, so that high-sensitivity and wide-frequency-response micro-seismic signal monitoring can be realized.

The invention discloses an optical phase control method and system of an interference system, relates to the technical field of optical phases, and solves the problems that the existing optical phase control technology is poor in control timeliness, large in error and difficult to consider convergence speed and steady-state jitter at the same time. An optical phase control method comprises the following steps: initializing a control quantity and a control parameter according to a target reference value of an optical phase; initializing a disturbance frequency and a block correlation quantity; driving voltage is input into the phase actuator, and a detection voltage signal is collected; updating the error amount, the cost amount and the disturbance amplitude; judging whether the control parameter is a current control parameter or not according to the error amount; and updating the control quantity un to complete the control of the optical phase. An optical phase control system comprises a microcontroller MCU, a DAC digital-to-analog conversion module, a phase actuator, an optical detection module and an ADC analog-to-digital conversion module. The method is suitable for the phase stabilization fields of optical fiber interferometers, phase modulation / compensation, coherent detection and the like.

The invention discloses a single-photon detector spectral response calibration device based on a quantum light source, and belongs to the field of quantum optics and quantum information. The device comprises a pump laser light source, a laser lens, a quantum light source module, a light source collection module, a polarization-dependent unequal-arm optical fiber interferometer, a to-be-detected single-photon detector and a time-dependent counter. A collinear spontaneous parametric down-conversion quantum light source is used as an input light source to carry out single-photon detector spectral response test, and the measurement precision can be traced to a Planck constant. The quantum light source is adopted for calibration, so that the damage risk possibly generated when strong light is input into the single-photon detector, and strong light darkening counting and post-pulse can be reduced. A dispersion compensation optical fiber is adopted as a single photon frequency domain-time domain converter, and an optical fiber polarization correlation unequal arm interferometer is adopted to calibrate the spectral response of the same detector through high-precision time counting without the help of a reference detector and a low-temperature refrigeration single photon spectrometer.

The application discloses a kind of based on optical fiber distributed sensor's drill bit state monitoring device and method, belong to oil drilling technical field.The application is by laying multiple groups of optical fiber sensor on drill bit, to collect and analyze the temperature distribution, strain distribution and vibration distribution data when drill bit works, according to strain distribution obtains the weight on bit distribution of drill bit, the state of drill bit is monitored in real time, and carry out drill bit working state prompt and realize alarm function.The strain measurement in monitoring process can but not limited to utilize the optical fiber strain sensing mechanism based on vernier effect, combine vernier sensitization effect with optical fiber interferometer light transmission characteristics, not only can more sensitively perceive the change of strain, improve the sensitivity of sensor, also can avoid the influence of ambient temperature on drilling pressure measurement result, realize the weight on bit distribution curve of drill bit of drilling equipment and the alarm function such as drilling pressure distribution abnormal due to cutting tooth wear.

The invention provides a high-accuracy narrow-linewidth laser linewidth measuring system, which can directly quantify 1 / f noise of a delay optical fiber in a traditional delay self-heterodyne linewidth measuring device, and can accurately measure the linewidth of the laser under the condition that the influence of the noise of the laser is controlled to be the same. The thermal noise of the time-delay optical fibers with different lengths is compared by changing the lengths of the optical fibers of the two arms of the interferometer; normalized instantaneous phase noise of a laser is obtained by using a short optical fiber interferometer, and an integral line width spectral line is obtained by performing signal self-correlation and Wiener-Singqin theorem, so that spectral line broadening caused by optical fiber thermal noise introduced by a long optical fiber in a traditional delay self-heterodyne line width measurement method is avoided; the problems that the integral line width is widened and the measurement results of optical fibers with different lengths are inconsistent due to the fact that the measured differential phase noise is influenced by long-fiber noise disturbance existing in a traditional delay self-heterodyne system for a long time are solved, and the line width measurement accuracy of the narrow line width laser is improved.

The application discloses a single-pump four-wave mixing light source, which utilizes a light source spectrum widening technology generated by a third-order nonlinear effect in an optical fiber, and achieves spectrum conversion and light power transfer by injecting high-power pump light into a high-nonlinear optical fiber, so as to realize a wide-spectrum light source and high output power. The spectrum width and the power are related to the pump light source power and the parameters of the nonlinear optical fiber, and the light source power has no upper limit in theory. As a light source, the application can improve the detection precision of a high-precision fiber interferometer.

The application discloses a nonlinear wide spectrum fiber light source, which is a technology for expanding the spectrum of a light source by using the third-order nonlinear effect in an optical fiber. High-power laser with two wavelengths is injected into a high nonlinear optical fiber as pumping light to achieve spectrum conversion and light power transfer, so that a wide spectrum light source and high output power are realized. The width and power of the spectrum of the light source are related to the pumping light power and the parameters of the nonlinear optical fiber. The light source power theoretically has no upper limit. The light source is used for a high-precision fiber interferometer, which is a brand-new technical approach.

The invention discloses a low polarization fading noise fusion type multi-parameter distributed optical fiber sensing system. The broadband light source module generates a modulated light signal and transmits the modulated light signal to the optical fiber circulator, and the 2 * 2 optical fiber coupler is cascaded with the 2 * 1 optical fiber coupler and the depolarization module to form an optical fiber interferometer. The output port of the optical fiber circulator is connected with the incident end of the optical fiber interferometer; and the output end of the 2 * 1 optical fiber coupler is connected with a section of long-distance transmission sensing optical fiber. Downlink output light of the 2 * 2 optical fiber coupler and output light of the optical fiber circulator enter the 2 * 2 optical fiber coupler and are connected with a signal receiving and processing module through a photoelectric converter for double-signal synchronous detection, optical information is demodulated from the two parts of intensity and frequency, real-time detection of physical parameters such as vibration, temperature and stress is achieved, and real-time and uninterrupted detection is guaranteed. According to the invention, the defects of single demodulation mode, high noise, complex structure and the like of a traditional distributed optical fiber sensing system are overcome, and multi-parameter sensing application is realized while the polarization fading noise of an interference type optical fiber sensing system is effectively reduced.

A fiber laser with a wide-range, fast-tuning center frequency is disclosed. The device comprises a pump laser with a pump laser controller, a wavelength division multiplexer, a gain fiber, a fiber circulator, a first fiber coupler, a second fiber coupler, a third fiber coupler, an electro-optic phase modulator, a broadband filter, and an electro-optic phase modulator controller. This invention combines fiber interferometer mode selection technology with rapid phase modulation technology of the electro-optic phase modulator. Rapid phase modulation of the electro-optic phase modulator enables rapid changes in the equivalent cavity length within the fiber interferometer, ultimately achieving rapid changes in the fiber interferometer modes. Furthermore, a fiber optic F-P tunable filter filters out redundant fiber interferometer modes, ultimately realizing a fiber laser with a wide-range, fast-tuning center frequency, exhibiting both a wide tuning range and a large tuning bandwidth.

This invention discloses an arbitrary-band frequency stabilization device based on a dual interferometer, comprising: a dual-fiber interferometer module for generating interference signals related to temperature and frequency changes; a temperature control module for temperature control of the dual interferometer module; and a control module for receiving the interference signals and outputting control commands accordingly. The dual interferometer module includes an equal-arm interferometer and an unequal-arm interferometer. The equal-arm interferometer responds to temperature changes and outputs a first interference signal; the unequal-arm interferometer responds to frequency changes and outputs a second interference signal. The control module receives the first interference signal and outputs a first control command to the temperature control module to improve temperature control accuracy. The control module receives the second interference signal and outputs a second control command to a laser to adjust the laser frequency. This device can effectively reduce costs while maintaining a stable and continuously tunable laser frequency.

The present invention relates to the technical field of optical fiber testing. Provided are an optical fiber fault locating method and apparatus, an electronic device and a storage medium. The method comprises: by means of an optical fiber interferometer, acquiring original optical fiber attenuation information; on the basis of the original optical fiber attenuation information, obtaining a cable length to an optical fiber fault point; on the basis of cable lengths to standard reference points, ground positions of the standard reference points and the cable length to the optical fiber fault point, obtaining a first ground position of the optical fiber fault point; on the basis of the first ground position of the optical fiber fault point, determining a fault point zone, fault point zones including a densely built-up zone and a sparsely built-up zone; when the fault point zone is a densely built-up zone, obtaining a second ground position of the optical fiber fault point on the basis of a GIS map and the cable length to the optical fiber fault point; and when the fault point zone is a sparsely built-up zone, inputting the cable length to the optical fiber fault point into a pre-trained historical fault data model to obtain a third ground position of the optical fiber fault point. The present invention achieves accurate location of positions of optical fiber faults.

The invention relates to the technical field of measurement, and provides a temperature drift resistance measuring device and method for the arm length difference of an all-fiber interferometer, and the device comprises a sweep frequency laser, a first coupler, an auxiliary interferometer, a measured interferometer connection terminal, a detector, and a program controller which are connected in sequence. A tested interferometer is connected between the tested interferometer connecting terminals; the auxiliary interferometer comprises a reference interference path, the reference interference path comprises upper arm optical fibers and lower arm optical fibers, and the lower arm optical fibers are connected in parallel; the reference interferometer structure comprises a second coupler, a temperature control module and a replaceable optical fiber section; the temperature control module provides a set temperature environment for the replaceable optical fiber section; and the second coupler adopts a multi-input multi-output structure and is connected to the two ends of the lower arm optical fiber and the two ends of the replaceable optical fiber section respectively. According to the device, the influence of temperature on arm length difference testing can be inhibited, and meanwhile, a replaceable light path structure is provided, so that the method can better adapt to the testing requirements of different arm length differences.