44 results about "Fiber interferometer" patented technology

The present invention relates to the field of communication and sensing, and specifically to a communication and sensing integrated device based on a seven-core optical fiber interferometer and an application method therefor. The application method comprises: a first beam splitter splitting, into reference light and signal light, a light source emitted by a narrow linewidth laser; performing modulation by means of a first coherent optical transmitter and a second coherent optical transmitter; amplifying the light by means of a first amplifier and a second amplifier, and then enabling the light to pass through a multi-core optical fiber from a fan-in end, and to output from a fan-out end; performing beam splitting by means of a second beam splitter and a third beam splitter, and performing demodulation by means of a first coherent receiver and a second coherent receiver; and finally, a phase-locked loop performing interference elimination on preliminarily-demodulated reference light and preliminarily-demodulated signal light to obtain finally-demodulated reference light and finally-demodulated signal light. The present invention uses a phase-locked loop to further eliminate disturbance noise of reference light and signal light. Therefore, noise interference is eliminated in continuous low-frequency detection, thereby improving the communication and sensing effect.

The invention discloses a frequency stabilized laser based on a double-fiber interferometer. The frequency stabilized laser comprises a narrow linewidth laser, an acousto-optic frequency shifter, a 1 * 2 fiber splitter I, the double-fiber interferometer, a voltage-controlled oscillator and a control module, the output end of the narrow linewidth laser is connected with the input end of the acousto-optic frequency shifter, and the two input ends are connected with the second output end and the third output end of the control module respectively. The driving input end of the acousto-optic frequency shifter is connected with the output end of the voltage-controlled oscillator, and the output end of the acousto-optic frequency shifter is connected with the input end of the 1 * 2 optical fiber splitter I; one output end of the 1 * 2 optical fiber splitter I outputs a frequency-stabilized laser signal, and the other output end of the 1 * 2 optical fiber splitter I is connected with the input end of the double-optical-fiber interferometer; the output end of the double-fiber interferometer is connected with the input end of the control module; the first output end of the control module is connected with the voltage-controlled oscillator, and the second and third output ends are connected with the narrow linewidth laser. According to the invention, laser signal output with high precision and high frequency stability is realized, and the frequency stability of the laser is three to four orders of magnitude higher than that of a narrow linewidth laser.

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 utility model discloses an optical lens for an optical fiber interferometer lens, and belongs to the field of optical lenses. An optical lens for an optical fiber interferometer lens comprises an interferometer main body lens, an optical lens assembly is fixed on one side of the interferometer main body lens, a lens mounting inner frame is fixed on the inner side of the optical lens assembly, a lens is attached to one side of the lens mounting inner frame, and the lens is fixed on the other side of the interferometer main body lens. According to the utility model, the fixing position can be rapidly adjusted according to the thickness of the lens through the fixing member, so that the optical lens can be flexibly adapted to various lenses with different thickness specifications, the universality of the lens is enhanced, and different experiment or detection requirements can be met no matter the lenses with different parameters are replaced. The optical lens assembly can be conveniently and quickly adjusted and fixed when the lens assembly is used for mounting lenses of different batches and different specifications in the production and manufacturing process, so that the stability of the overall performance of the optical lens is ensured, the whole lens assembly does not need to be replaced due to the thickness change of the lens, and the use cost and the operation complexity are reduced.

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 relates to the technical field of underwater optical imaging, in particular to a fiber integrated modulation underwater long-distance optical detection system, a laser illumination optical module is used for emitting two beams of light with an included angle to an underwater target water body area, the two beams of light form spatial variation interference fringes in the target water body area, and light and shade alternate illumination light is generated; the Sabortus imaging optical module is used for shooting a target water body area under the illumination light according to Sabortus imaging conditions to obtain an underwater space image; and the circuit control core group is used for controlling the laser illumination optical module to emit two beams of light and collecting underwater space images from the Sabortus imaging optical module. According to the invention, a fiber integrated modulation fiber interferometer structure is introduced as a light source output regulation and control module, so that an emergent beam forms an angle to realize space interference, the regulation and control performance of a light source part of a traditional Saborne imaging laser radar is effectively improved, the size and weight are effectively reduced, and the Saborne imaging laser radar has the advantages and characteristics of low cost and stability.

The invention discloses an asymmetric laser interferometer type long-distance detection demodulation system and a disturbance positioning method, the system comprises two lasers, a Mach-Zehnder fiber interferometer, a data acquisition card and an industrial personal computer, and the two lasers provide narrow linewidth light sources with unequal central wavelengths; the two paths of light sources enter the Mach-Zehnder optical fiber interferometer clockwise and anticlockwise respectively, and the two paths of signal light share the same sensing optical fiber link during detection; a phase modulator introduces a high-frequency carrier signal on one path of sensing optical fiber, and performs high-frequency carrier modulation on a corresponding sensing optical signal; then the two paths of sensing interference optical signals enter an industrial personal computer after respectively passing through an erbium-doped optical fiber amplifier, a dense wavelength division multiplexer, a photoelectric detector and a data acquisition card, and phase information introduced by a disturbance event is demodulated by the two paths of interference sensing optical signals respectively through respective corresponding improved phase generation carrier algorithms; and specific position information of the disturbance event acting on the optical fiber link is analyzed through a cross-correlation time delay estimation theory.

The invention discloses a vertically-mounted asymmetric integral type optical fiber interferometer support and a design method thereof, and belongs to the field of optical fiber optics, the vertically-mounted asymmetric integral type optical fiber interferometer support comprises an upper support ring body, a lower support ring body and an annular connecting plate, the upper support ring body comprises an upper ring plate and an upper cylinder, and the upper ring plate and the upper cylinder are coaxially arranged and are of an integral structure; the lower support ring body comprises a lower ring plate and a lower cylinder, and the lower ring plate and the lower cylinder are coaxially arranged and are of an integrated structure. The upper cylinder body and the lower cylinder body are coaxially arranged and are of an integrated structure, the upper cylinder body and the lower cylinder body form a connecting cylinder, and the annular connecting plate is arranged outside the connecting cylinder in a sleeving mode; the size of the upper annular plate is different from that of the lower annular plate, the size of the upper barrel is different from that of the lower barrel, the upper support annular body and the lower support annular body are of an asymmetric structure, the upper annular plate, the upper barrel and the annular connecting plate jointly define an upper winding groove, and the lower annular plate, the lower barrel and the annular connecting plate jointly define a lower winding groove. Therefore, the vibration sensitivity of the optical fiber interferometer support can be reduced.

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 discloses a miniaturized three-axis optical fiber gyroscope optical path which comprises a micro-optical array module and a plurality of optical fiber interferometer modules, and the micro-optical array module and the optical fiber interferometer modules are connected through mode filtering optical fibers with a certain length. The micro-optical array module is composed of a semiconductor light-emitting chip, four microcrystal lenses with different functions and three PD light detection chips made of InGaAs materials. The optical fiber interferometer module is composed of a Y waveguide, an optical fiber ring connected with the Y waveguide, and an optical fiber ring packaging structural member. According to the design, through overall arrangement of the micro-optical array, the optical path loss of light output by the semiconductor light-emitting chip to each PD optical detection chip is about 17dB and is lower than that of a single-axis optical path, and the signal-to-noise ratio of the three-axis integrated fiber-optic gyroscope can be improved. And under the same signal-to-noise ratio requirement, the requirements on the efficiency of the semiconductor light-emitting chip and the light source driving current are also relaxed, and the optical fiber light path design of the three-axis gyroscope can be realized by using the conventional light source parameters of the current single-axis light path.

The application discloses a fusion type optical fiber distributed multipoint disturbance detection demodulation system and a multipoint fault positioning method. The system comprises two light sources, a one-way Mach-Zehnder optical fiber interferometer, a phase-sensitive optical time domain reflectometer and a data acquisition and processing module. When multiple abnormal vibration events simultaneously act on a sensing optical fiber, a continuous laser signal emitted by a first laser enters the one-way Mach-Zehnder interferometer, and a continuous interference sensing optical signal is received by a photodetector in real time. A continuous laser signal emitted by a second laser enters the phase-sensitive optical time domain reflectometer and the one-way Mach-Zehnder interferometer after being converted into a periodic pulse optical signal, and a pulse optical signal is received by the photodetector in real time. A data acquisition and processing module adopts an improved phase generation carrier phase demodulation scheme to demodulate phase changes of vibration signals applied on the sensing optical fiber, so as to calculate amplitude-frequency information. Position information of multiple fault events is demodulated by using obtained backscattering Rayleigh scattering light signals.

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.

A temperature monitoring device according to the invention comprises a control system (100) adapted to generate a substantially periodic control waveform applied to a control input of a light source (111) with a tunable wavelength connected to a fiber interferometer (112), wherein a measuring fiber (120) is connected in an arm of one of the fiber interferometers (112) and the interferometer (111) output is connected to a detector (113), the output of the detector (113) being connected to a signal processing module (101) adapted to identify temperature changes as a function of the fiber length, characterized in that the coherence length of the light source (111) is longer than 0.5 m and the period of the periodic waveform is shorter than or equal to 20 s, the difference between the minimum and maximum wavelengths is higher than 3 pm, and the fiber is adapted to be placed near an energy-discharging device in a vehicle during its operation. A temperature monitoring method according to the invention is characterized in that the temperature is determined by cumulatively taking into account changes detected at measurement points on the measuring fiber of the device using the device according to the invention. A temperature monitoring system according to the invention is characterized in that the measuring fiber of the device according to the invention is placed near an energy-discharging device in a vehicle.

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 embodiment of the invention provides a vibration information determination method and a multi-wavelength optical fiber vibration interferometer system, and relates to the technical field of forward optical fiber interferometers. The vibration information determination method is applied to a multi-wavelength optical fiber vibration interferometer system (comprising a wavelength division multiplexer, an optical fiber link, a coherent demodulation device and a data processing unit), and comprises the following steps: enabling N paths of laser with different wavelengths to simultaneously enter the optical fiber link by the wavelength division multiplexer, each laser carries vibration information of n vibration events along the optical fiber link, N is greater than or equal to 2n, and N and n are positive integers; the coherent demodulation device performs coherent demodulation on the N paths of lasers with different wavelengths to obtain phase information of the N paths of lasers with different wavelengths; and the data processing unit solves a waveform-position equation set according to the phase information of the N paths of lasers with different wavelengths, and determines the vibration positions and the vibration waveforms of the n vibration events. Therefore, the vibration position and the vibration waveform can be determined at the same time through one interferometer.

The invention provides a high-precision real-time FMCW laser ranging system and method based on a ZYNQ system, and belongs to the field of fiber interferometer measurement, the system comprises two main interferometers, an auxiliary interferometer, a high-speed signal acquisition unit and a real-time signal processing unit, the real-time signal processing unit comprises a PL and a PS which are connected, the high-speed signal acquisition unit respectively acquires upper frequency sweeping signals and lower frequency sweeping signals of the main interference signals and the auxiliary interference signals and transmits the acquired signals to the PL, and the two main upper frequency sweeping signals, the two main lower frequency sweeping signals, the auxiliary upper frequency sweeping signals and the auxiliary lower frequency sweeping signals form two main-auxiliary upper frequency sweeping signal pairs and two main-auxiliary lower frequency sweeping signal pairs; and the PL performs parallel phase demodulation according to the main-auxiliary up-scanning signal pair and the main-auxiliary down-scanning signal pair at the same time to obtain four paths of echo phase information, and the PS calculates four distance values through least square fitting according to the four paths of echo phase information in sequence. The method has the high-speed, real-time and high-precision distance measurement capability.

The invention discloses a multifunctional composite optical fiber interferometer for monitoring the phase change process of poly (N-isopropylacrylamide) as well as a preparation method and application of the multifunctional composite optical fiber interferometer, and relates to the technical field of optical fiber chemical sensing. The core architecture of the system is formed by tightly connecting and combining a Fabry-Perot interferometer sensitized by PDMS microspheres and a Mach-Zehnder interferometer excited by a coreless optical fiber. Comprising a gold film, PDMS microspheres, an input single-mode optical fiber, a staggered single-mode optical fiber, a coreless optical fiber and an output single-mode optical fiber, wherein the input single-mode optical fiber, the staggered single-mode optical fiber, the coreless optical fiber and the output single-mode optical fiber are connected in sequence. Compared with the traditional scheme, the multifunctional composite optical fiber interferometer provided by the invention not only has higher sensitivity and time resolution, but also has the advantages of low invasiveness and real-time in-situ monitoring, and a new solution is provided for monitoring the phase change process of the poly N-isopropylacrylamide.

The invention relates to a multi-way switch temperature and humidity detection method based on sensing structure sensitivity difference. The method comprises a DFB narrow-band laser and the following steps: connecting the DFB narrow-band laser with an optical switch through an optical fiber circulator; the optical switch is an electric control tunable optical switch, realizes port optical transmission switching through a driving circuit, and is controlled by the embedded development board through a programmable program; each channel of the optical switch performs cascade connection on the double-cone temperature sensor, the FP temperature sensor and the PVA double-cone humidity sensor; a driving circuit is controlled by an IO port of an embedded development board to open a channel of an optical switch, after collected data is processed through an algorithm and displayed, all sensors are regularly switched, sensing response signals are extracted and processed in a quasi-synchronous mode, and therefore temperature and humidity detection is conducted on the different sensors in sequence. Light intensity demodulation is carried out on different types of optical fiber interferometers through a single loop, and the problem that the optical domain detection cost is high is solved.

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.