55 results about "Vernier effect" patented technology

The invention discloses a high-sensitivity double Fabry-Perot interference hydrogen sensor resistant to temperature and humidity interference, and belongs to the technical field of optical fiber sensing. A modular integrated design is adopted, and the core comprises double Fabry-Perot interferometers which are connected in series and are respectively a temperature compensation unit FPI-1 and a hydrogen sensing unit FPI-2, and a matched software controllable vernier processing module; the FPI-1 realizes temperature real-time compensation by filling PDMS in an open microcavity, and the FPI-2 adopts a PDMS / Pd-WO3 composite material as a hydrogen sensitive layer, and has wide humidity range anti-interference capability through structural optimization; the weak hydrogen signal is amplified through Fourier transform filtering, sine function fitting, twin interference spectrum construction and vernier effect. According to the invention, precise detection of ultra-trace hydrogen in a complex temperature and humidity environment is realized, and the temperature and humidity interference resistance is high.

The invention relates to the technical field of optical fiber sensors, in particular to a double-parameter optical fiber sensor based on a double interference effect and a preparation method thereof.The sensor comprises a sensing unit 5 based on a Fabry-Perot interferometer and a sensing unit 6 based on a Mach-Zehnder interferometer, and the two sensing units form a cascade structure; mutual reference probes can be realized when different parameters are measured; according to the invention, an approximate free spectral range is obtained by controlling the cavity length, a remarkable vernier effect is formed, the air pressure and temperature sensitivity can be calculated by tracking the drift of the envelope, the measurement accuracy can be effectively improved, and the device has the advantages of simple structure and small volume.

The application belongs to the technical field of optical communication and relates to a frequency-shift-free microwave photonic channelized receiving device, which comprises a carrier light frequency comb generating unit, a local light frequency comb generating unit, an electro-optical modulation unit, an optical phase shift unit, a channel selection and spectrum processing unit and a plurality of photoelectric conversion units. The received broadband radio frequency signal is modulated on each comb tooth of the carrier light frequency comb through the electro-optical modulation unit, and the frequency alignment between the optical local oscillator and the required receiving sub-channel can be realized based on the "vernier" effect caused by the different free spectral ranges of the carrier light frequency comb and the local light frequency comb and the inherent frequency alignment of the same pump laser. The mirror image sub-channel suppression is realized based on the opposite optical phase shifts on both sides of the pump light. The application has a simple structure, omits the frequency shift and special modulation structure required for frequency alignment, effectively suppresses the inter-channel crosstalk problem in the channelized receiving process, and can flexibly increase the channelization quantity according to actual needs.

The invention discloses a vernier effect-based high-sensitivity double-dislocation optical fiber temperature sensor, which comprises an input optical fiber, a first dislocation optical fiber, a second dislocation optical fiber, an output optical fiber and a polymer microsphere which are connected in a dislocation manner, one end of the input optical fiber and one end of the first staggered optical fiber are welded in a staggered manner, and a first staggered welding surface is formed therebetween; the other end of the first staggered optical fiber and one end of the second staggered optical fiber are welded in a staggered manner to form a second staggered welding surface; the other end of the second dislocation optical fiber is in dislocation welding with one end of the output optical fiber to form a third dislocation welding surface; and the polymer microspheres are wrapped on a staggered cavity between the second staggered welding surface and the third staggered welding surface. According to the optical fiber temperature sensor, the staggered optical fiber pairs of the two Mach-Zehnder interferometers are formed, one staggered optical fiber is coated with the polymer, and therefore the vernier effect is achieved, and the optical fiber temperature sensor has the advantages of being high in temperature measurement sensitivity, easy to prepare and low in cost.

The application discloses a fiber refractive index sensor based on a vernier effect, which comprises a broadband light source, an isolator, a first fiber ring resonant cavity, a second fiber ring resonant cavity, a refractive index sensitive unit, a spectrum analysis module and a data processing unit; the input end of the isolator is connected with the output end of the broadband light source; the input end of the first fiber ring resonant cavity is connected with the output end of the isolator; the input end of the second fiber ring resonant cavity is connected with the output end of the first fiber ring resonant cavity; the first fiber ring resonant cavity and the second fiber ring resonant cavity constitute a cascaded fiber ring resonant cavity; the refractive index sensitive unit is connected into the second fiber ring resonant cavity; the input end of the spectrum analysis module is connected with the output end of the second fiber ring resonant cavity; and the input port of the data processing unit is connected with the output port of the spectrum analysis module. The application has the characteristics of high sensitivity, simple structure, high demodulation precision and suitability for mass production.

Permanent magnet synchronous joint motor, magnetic encoder and angle detection method, relate to motor angle detection technical field. The magnetic encoder contains a magnetic encoder module and an AMR sensor array. The magnetic encoder module is suitable for being installed at the motor shaft end. The magnetic encoder module includes coaxially arranged outer ring magnet and inner ring magnet. The absolute value of the difference between the pole pairs of the outer ring magnet and the inner ring magnet is 2. The AMR sensor array is suitable for being arranged in the magnetic field action area of the outer ring magnet and the inner ring magnet. The AMR sensor array includes two AMR sensors located on the same radius line of the magnetic field action area. Two AMR sensors correspond to the magnetic field area of the outer ring magnet and the inner ring magnet respectively, and are used for synchronously collecting the signals of the respective corresponding magnetic ring. The signals are suitable for realizing high-resolution detection of single-turn absolute angle through double-ring vernier effect and disambiguation algorithm.

This invention discloses an alcohol detection chip and detection method based on a cascaded dual-ring resonator with dual-gradient curvature, belonging to the field of optical micro-nano sensing and integrated optics technology. This invention aims to solve the technical problems of low sensitivity, poor resolution, complex spectral analysis, and weak environmental adaptability in traditional micro-ring sensing devices, as well as the low detection accuracy of existing miniaturized equipment. The chip uses a silicon-based substrate and includes input and output waveguides, cascaded dual micro-rings, a coupling region, and two sets of miniature heating electrodes. The micro-rings employ dual-gradient waveguides with circular and Euler-circular curved structures for the inner and outer curves, respectively. The cascaded dual rings create a vernier effect, broadening the free spectral range. By adjusting the resonant wavelength through the heating electrodes, scanning detection is completed in the characteristic alcohol band around 1400nm, and high-precision alcohol measurement is achieved by combining transmission spectroscopy. This invention has a compact structure and low cost, and is suitable for rapid quantitative detection of alcohol in industrial monitoring, vehicle safety, food safety, and other scenarios.

The invention belongs to the technical field of temperature detection, and particularly relates to an enhanced vernier effect optical fiber temperature sensor, a preparation method thereof and a temperature sensing system. The invention provides an enhanced vernier effect optical fiber temperature sensor, which comprises a Fabry-Perot interferometer and a Liushu interferometer, and the Fabry-Perot interferometer and the Liushu interferometer are connected in parallel. The Fabry-Perot interferometer comprises a single-mode optical fiber and a hollow optical fiber fixedly connected with the single-mode optical fiber, and a cavity of the hollow optical fiber is filled with polydimethylsiloxane; the Liusu interferometer comprises an optical fiber polarizer and a second polarization maintaining optical fiber fixedly connected with a first polarization maintaining optical fiber of the optical fiber polarizer. The enhanced vernier effect optical fiber temperature sensor provided by the invention is simple in preparation process and can realize batch production; and moreover, the bandwidth utilization rate is higher, the sensitivity is higher, and the ultra-high-sensitivity use scene can be met. And high-sensitivity temperature monitoring can also be realized when the equipment condition is relatively poor. And the use threshold of the vernier sensor is obviously reduced.

The invention belongs to the technical field of temperature sensing, and particularly relates to an optical fiber temperature sensor based on a double-FP parallel structure, which is characterized in that the optical fiber temperature sensor is formed by connecting a reference interferometer and a sensing interferometer in parallel, the reference interferometer is composed of a first single-mode optical fiber, a hollow-core optical fiber and a second single-mode optical fiber, and the sensing interferometer is composed of a second single-mode optical fiber and a third single-mode optical fiber. The sensing interferometer is composed of a third single-mode fiber, a PDMS cavity and a fourth single-mode fiber. Wherein the optical path lengths of the PDMS cavity and the hollow-core optical fiber are controlled to be close to each other but not equal to each other, so that the free spectral range of the sensing interferometer is close to each other but not equal to the free spectral range of the reference interferometer, and the vernier effect of an output spectrum is excited to form an envelope formed by fine stripes. The optical fiber temperature sensor has the advantages of being high in sensitivity and linearity, large in detection range, good in repeatability and good in reversibility, meanwhile, the size of the optical fiber sensing probe is in the micron dimension, and the optical fiber temperature sensor is suitable for temperature detection in a narrow space.

The invention discloses a vernier effect reconstruction-based signal processing method and related equipment, and the method comprises the steps: carrying out the cascading processing of an optical fiber core offset pair and a micro-nano optical fiber, obtaining a vernier effect optical fiber sensor, inputting a to-be-detected signal into the vernier effect optical fiber sensor, and obtaining an output signal, and performing vernier effect reconstruction processing on the output signal to obtain a reconstructed vernier envelope, and performing parameter measurement processing on the signal to be measured according to the reconstructed vernier envelope to obtain a measurement result. The embodiment of the invention can improve the measurement efficiency of the sensor, and can be widely applied to the technical field of data processing.

The invention provides a wooden ancient building multi-defense-area intrusion and fire danger integrated monitoring system, and belongs to the technical field of distributed optical fibers. The system comprises a broadband light source, laser emitted by the broadband light source is divided into two paths after passing through a first 1 * 2 coupler, the two paths of laser are input into two composite structure light paths respectively, each composite structure comprises an annular Sagnac interference structure and an MZ type interference structure which are parallel to each other, the annular Sagnac interference structures are used for monitoring the temperature in an arranged defense area, and the MZ type interference structures are used for monitoring the temperature in the defense area. Intrusion vibration events around the ancient building are monitored through an MZ type interference structure; according to the system, a Sagnac structure and an MZ structure are multiplexed in parallel, the vernier effect is ingeniously utilized, function integration on a single sensing optical fiber is achieved, and material consumption and installation complexity are remarkably reduced; besides, the panda type polarization maintaining optical fiber is integrated in the annular Sagnac structure, and the MZI made of the tapering single-mode optical fiber is combined, so that the sensitivity of temperature sensing and perimeter security protection is greatly improved, and the high-standard requirement of security protection of ancient buildings is met.

The utility model discloses a polydimethylsiloxane sensitization optical fiber temperature and strain simultaneous measurement sensor. The sensor comprises an incident optical fiber, an optical fiber coupler, an optical fiber patch cord, a transmission optical fiber, a sensing cavity, a reference cavity and an emergent optical fiber, an optical signal enters the optical fiber coupler through the incident optical fiber and is divided into two beams of equal-intensity light in the coupler, the two beams of light are respectively input into the transmission optical fiber through the optical fiber patch cord and then enter the sensing cavity and the reference cavity which are coated with the polydimethylsiloxane, and the light is reflected by the cavities to form interference; the interference light is transmitted back to the optical fiber coupler through respective transmission optical fibers, so that a vernier spectrum is formed; the emergent optical fiber transmits an optical signal containing temperature strain information to a spectrograph, trough drift is analyzed through a dual-wavelength matrix demodulation method, and simultaneous measurement is achieved. According to the utility model, the vernier effect, the structural advantages of the Fabry-Perot interferometer and the advantage of high thermo-optic coefficient of polydimethylsiloxane are combined, and the vernier interferometer has the advantages of low cost, high sensitivity, high stability and the like.

The application relates to a tunable laser, which comprises a channel selection component, a plurality of optical amplifiers, a micro-ring filter component and a reflection component, the micro-ring filter component is coupled with the reflection component, and the working wavelength range of each optical amplifier is different; wherein: the channel selection component is used for selecting any optical amplifier to input a gain optical signal into the micro-ring filter component; the micro-ring filter component is used for filtering the gain optical signal under a vernier effect to obtain a filtered optical signal and then inputting the filtered optical signal into the reflection component; and the reflection component is used for outputting part of the filtered optical signal to the outside and reflecting the other part of the filtered optical signal to the optical amplifier currently selected by the channel selection component after the other part of the filtered optical signal passes through the micro-ring filter component. The wavelength range of the laser tuning of the application is large.

The invention discloses a miniaturized adjustment-free ultra-narrow linewidth composite filtering external cavity semiconductor laser, which belongs to the field of semiconductor lasers and is sequentially provided with a gain chip, an aspherical lens, a first FP etalon, a second FP etalon, an interference filter, a partial reflector, an optical isolator and a polarization maintaining optical fiber collimator. Wherein the first FP etalon and the second FP etalon are superposed in a non-coaxial mode to form a free spectral range difference, a longitudinal mode interval difference is generated through a Vernier effect, and a longitudinal mode interval generated by the Vernier effect is controlled by adjusting a dip angle difference between the first FP etalon and the second FP etalon. Through machining precision, optical coupling optimization and an automatic assembly technology, the problems of wide tuning bandwidth, ultra-narrow linewidth, multi-dimensional performance collaboration and environmental adaptability are synchronously solved.

The application provides a two-parameter measurement optical fiber sensor based on harmonic vernier effect and a manufacturing method, and belongs to the field of optical communication.The sensor comprises, from the incident end to the emission end, an incident single-mode optical fiber, a first multi-mode optical fiber, a first ring-core optical fiber, a third multi-mode optical fiber, a second ring-core optical fiber, a second multi-mode optical fiber and an emission single-mode optical fiber arranged in sequence.The adjacent optical fibers are fused, the cross sections of the cores of the multi-mode optical fibers are all larger than those of the adjacent other optical fibers, and the cross section of the core of the ring-core optical fiber is larger than that of the core of the single-mode optical fiber.The length of the first ring-core optical fiber is such that the reflected light of the first end face and the reflected light of the second end face form a Fabry-Perot interference, and the proportion of the first ring-core optical fiber to the second ring-core optical fiber is such that a harmonic vernier or a basic vernier is generated.The two interferometers of the sensor share the same optical fiber structure, the cascaded double chambers generate the harmonic vernier effect, the sensitivity of the sensor is improved, and the different responses of the FPI and the MZI to the external temperature and strain are utilized, so that the dual-parameter sensing function is realized.

The invention discloses a method and device for amplifying the sensitivity of an interference type optical fiber sensor, and relates to the technical field of optical fiber sensing, and the method comprises the steps: collecting original broadband light source spectral data, constructing an artificial spectral data set based on the original broadband light source spectral data and a virtual spectral data set, the method comprises the following steps: acquiring measured spectral data of an interference type optical fiber sensor in a to-be-measured environment in real time, selecting reference spectral data according to a preset target magnification factor, subtracting through a spectrograph channel to obtain a vernier effect spectral data set, performing upper envelope fitting operation on each piece of vernier effect spectral data, recording a wavelength value corresponding to a feature tracking point, and calculating the spectral data of the interference type optical fiber sensor according to the wavelength value. And obtaining a predicted value of the physical quantity to be measured based on demodulation of the wavelength value-physical quantity parameter table. According to the virtual spectrum data set generating and processing method, the sensitivity of the interference type optical fiber sensor is remarkably improved, the system structure is simplified, the cost is reduced, and the stability and reliability of the system are improved.

The invention discloses an optical fiber double-parameter sensor based on a quadratic vernier effect, and belongs to the technical field of optical fiber sensors. Light splitting is carried out through an SLD wide-spectrum light source and a first 3dB coupler, a Solc-Sagnac interferometer (containing two sections of small-diameter polarization maintaining optical fibers welded by 90 degrees) and a Sagnac interferometer (containing a single section of small-diameter polarization maintaining optical fibers) are connected in parallel, two paths of optical signals are modulated and then synthesized through a fourth 3dB coupler, and a spectrometer displays a finally output spectrum. Wherein the Solc-Sagnac interferometer generates a first vernier effect, free spectral width matching of the Sagnac interferometer and the Solc-Sagnac interferometer is in a similar range, a second vernier effect is generated, the temperature and stress sensitivity is further amplified, and when temperature change / stress is applied, envelope trough displacement is doubly amplified, so that the temperature and stress sensitivity is improved. The optical fiber double-parameter sensor has the advantages of being small in size, simple in structure, capable of achieving double-parameter measurement, high in sensitivity and the like.

The invention discloses a four-micro-ring band-pass filter which comprises a first linear waveguide, a second linear waveguide and a third linear waveguide which are parallel to one another and are sequentially arranged in a first direction, and the first linear waveguide, the second linear waveguide and the third linear waveguide extend in a second direction perpendicular to the first direction; the first micro-ring and the second micro-ring are arranged between the first linear waveguide and the second linear waveguide and are sequentially arranged along a first direction; and the third micro ring and the fourth micro ring are arranged between the second linear waveguide and the third linear waveguide and are sequentially arranged along the first direction. By cascading the two double-ring filters with different radiuses and utilizing the vernier effect, the ultra-large FSR of the C wave band is realized while the low loss is ensured, the structure is compact, the process is mature, and the thin-film lithium niobate optical chip is suitable for preparation and application of a large-scale thin-film lithium niobate optical chip.

The application discloses a kind of based on CPT effect microcavity double optical comb frequency stabilization device, two self-injection locking microcavity optical comb are used to obtain microcavity double optical comb, and microcavity double optical comb pump light source is locked;The repetition frequency of double optical comb is independently controlled by the way of radio frequency injection locking;Utilize microcavity double optical comb vernier effect, obtain the double optical comb comb teeth pair that can stimulate CPT effect, utilize atomic absorption peak to generate comb teeth frequency discrimination signal, feedback to pump light, so that pump light reference to the Doppler absorption peak of atom;The repetition frequency of one optical comb is referenced to comb teeth beat signal, and frequency discrimination signal is generated using CPT effect, and the repetition frequency of another optical comb is locked, so that the frequency difference of double optical comb comb teeth pair is locked to CPT resonance peak.The application can compensate the frequency difference between microcavity optical comb repetition frequency and microwave atomic frequency stabilization frequency by double optical comb vernier effect, realize the integration and miniaturization of frequency stabilization system, reduce the complexity of frequency stabilization system.

The invention discloses a demultiplexing comb-shaped Brillouin light source generating device for spectrum synthesis, which comprises a laser generator, a high-nonlinearity optical fiber and a demultiplexing grating, and is characterized in that the laser generator is used for modulating and generating first pumping comb-shaped laser and first signal comb-shaped laser, the high-nonlinearity optical fiber is connected with the laser generator, and the demultiplexing grating is connected with the high-nonlinearity optical fiber; the first pumping comb-shaped laser and the first signal comb-shaped laser are used for reversely transmitting the first pumping comb-shaped laser and the first signal comb-shaped laser, so that the first pumping comb-shaped laser and the first signal comb-shaped laser form comb-shaped Brillouin laser with a preset frequency under the action of stimulated Brillouin gain, and the demultiplexing grating is used for separating the comb-shaped Brillouin laser with the preset frequency into a preset frequency spectral line. According to the invention, by adjusting the frequency interval difference between the first pumping comb laser and the first signal comb laser, under the action of the spectrum vernier effect, the asynchronous light field can be used for driving and generating the comb Brillouin laser with the adjustable frequency interval.

The application belongs to the technical field of semiconductor optoelectronic devices, and particularly relates to a kind of integrated SOA compensation displacement grating DBR wide tuning laser system, comprising: gain chip area, for providing laser gain;Displacement grating DBR reflection area, optically coupled with gain chip area, constitutes DBR main laser cavity;Double micro-ring resonator module, comprising first micro-ring resonator and second micro-ring resonator;The radius of first micro-ring resonator and second micro-ring resonator is different, and wavelength selection is carried out on the output light of main cavity through vernier effect;Sagnac ring feedback structure, optically coupled with double micro-ring resonator module, for feeding back selected wavelength optical signal to gain chip area;Semiconductor optical amplifier, set outside main cavity, for power compensation of external cavity optical signal and optical signal fed back to laser main cavity.The scheme can realize wide tuning, high stability, low insertion loss single-mode laser output through precise regulation and control of displacement grating, combined with double micro-ring vernier mode selection, Sagnac locking and SOA compensation.

The application belongs to the technical field of fiber lasers, and discloses a stress tuning fiber laser, which comprises a pump laser, a wavelength division multiplexer, a gain fiber, an isolator, an output coupler, a circulator, a one-to-three coupler and a fiber reflector; the one-to-three coupler and the fiber reflector form a fiber interference filter for realizing wavelength tuning. The stress tuning fiber laser is used, the sensitivity of the fiber interference filter to strain is enhanced through a vernier effect, wavelength tuning is more convenient, the stress tuning fiber laser is simple to manufacture, does not need complex and expensive equipment, and cost is saved.

The invention discloses a vernier effect-based bullet-shaped optical fiber temperature sensing probe and a preparation method thereof. The bullet-shaped optical fiber temperature sensing probe comprises an optical fiber body, a cylindrical optical fiber cantilever fixed on the end surface of the optical fiber body, and a bullet-shaped polymer shell completely wrapping the cylindrical optical fiber cantilever. The optical fiber temperature sensing probe has the advantages of being compact in structure, wide in temperature measurement range and high in sensitivity, and has important application prospects in the fields of semiconductor manufacturing, minimally invasive surgery tissue thermal damage monitoring, embedded smart home and the like.

The invention discloses a half-wave coupling V-shaped cavity-based tunable semiconductor optical amplifier and a working method thereof. The half-wave coupling V-shaped cavity-based tunable semiconductor optical amplifier comprises a substrate, an epitaxial structure and a V-shaped resonant cavity, the V-shaped resonant cavity is composed of two FP cavities with different optical lengths and a half-wave coupler; the two FP cavities are isolated from the half-wave coupler through an electric isolation area and are respectively provided with an independent electrode. The method comprises the following steps: applying bias current to the coupler electrode; injecting a wavelength division multiplexing optical signal containing a multi-wavelength component; the effective refractive indexes of the two FP cavities are independently changed by adjusting injection currents of the first electrode and the second electrode respectively, so that the resonant wavelength of the FP cavities is tuned and aligned to the target wavelength. Based on the vernier effect and the unique phase design of the half-wave coupler, only the aligned target wavelength can resonate in the cavity and obtain high-gain amplification, and other wavelengths are strongly suppressed. The device is compact in structure, does not need an external filter, is good in process compatibility, facilitates the integrated mass production, is rapid in current tuning, and is suitable for a dynamic optical network.

The invention provides a temperature self-compensating optical fiber magnetic field measuring device and method, and relates to the technical field of optical fiber magnetic field sensing, the device comprises a broadband light source, an optical fiber coupler, a sensing head and a spectrum analyzer, the optical fiber coupler is provided with four ports; the broadband light source is connected with a first port of the optical fiber coupler; the spectrum analyzer is connected with a second port of the optical fiber coupler; and two ends of the sensing head are respectively connected with the third port and the fourth port of the optical fiber coupler. The optical fiber magnetic field measuring device is prepared by combining technologies of welding, filling, coating and the like, vernier effect sensitization and temperature self-compensation are realized by regulating and controlling parameters of the sensing head, and ambient temperature crosstalk is eliminated while the magnetic field intensity detection sensitivity of the sensor is improved by one to two orders of magnitude, so that accurate measurement of a magnetic field is realized.

The invention relates to an interferometer sensing measurement method based on a special reference spectrum vernier effect, which comprises the following steps: S101, according to a spectrum measurement range and an interferometer cavity length change range caused by a measured physical quantity, establishing a relational expression that a free spectral range (FSR) of a virtual reference interferometer spectrum changes along with wavelength; s102, obtaining a spectral curve of the reference interferometer; s103, superposing the actually measured spectrum curve of the sensing interferometer and the spectrum curve of the reference interferometer, and obtaining a total spectrum curve of which the envelope appears the characteristic wavelength based on a vernier effect; and S104, monitoring the change of the characteristic wavelength along with the measured physical quantity, and completing the measurement according to the calibrated relationship between the characteristic wavelength and the measured physical quantity. According to the invention, only one optical interferometer is needed, a special reference spectrum is constructed according to the measured physical quantity and the measurement range of the spectrum, and the unique recognizable characteristic wavelength can be obtained based on the vernier effect, so that the ambiguity resolution and high-sensitivity measurement of the physical quantity are realized.

The application discloses a multi-parameter eye axis measurement system based on self-mixing vernier effect and relates to the field of optical fibers. A light beam emitted by a low-coherence light source is divided into a fiber reference light and a fiber measurement light through a coupler; the fiber measurement light is output as spatial measurement light through a first circulator, and the spatial measurement light scans an eyeball through a zoom lens; the fiber measurement light enters a fiber delay line through a second circulator and a wavelength division multiplexer and is output from a reflection end of the second circulator after reflection; the spatial measurement light is output as first low-coherence light from a reflection end of the first circulator after reflection by the eyeball; sample measurement light is output as second low-coherence light from the reflection end of the second circulator; the two beams of low-coherence light interfere through a second coupler; a light beam emitted by a high-coherence light source is self-mixed in a phase shift grating to serve as a scale for low-coherence measurement, and the refractive power of the eyeball is calculated by collecting a Hartmann array diagram. According to the scheme, the data signal-to-noise ratio of the measurement data is higher, and the data is more accurate.

The invention discloses a vernier effect-based optical fiber air pressure sensor and a preparation method thereof, and relates to the technical field of optical fiber air pressure sensing. The method comprises the steps that firstly, polarization maintaining optical fibers are solidified in a ceramic ferrule, then the ceramic ferrule is inserted into a ceramic sleeve to be ground through a grinding machine, the distance between the two sections of polarization maintaining optical fibers is accurately adjusted in the grinding process, and an air cavity and a silicon dioxide cavity are obtained; by controlling the cavity lengths of the air cavity and the silicon dioxide cavity, a vernier effect is generated; according to the polarization characteristic of the polarization-maintaining optical fiber, the polarization principal axis directions of the two sections of polarization-maintaining optical fibers are adjusted to be consistent, and the reflection spectrum reaches the optimal contrast ratio. The distance between the polarization maintaining optical fibers at the two ends is controlled through a grinding method, the preparation process is simple, the lengths of the air cavity and the silicon dioxide cavity can be accurately controlled, and the sensitivity of the optical fiber air pressure sensor is improved; and the polarization principal axis directions of the polarization maintaining optical fibers are adjusted to be consistent, so that the contrast of the interference spectrum at the reflection end of the barometric sensor is improved, and the application prospect is better.

An optical sensing assembly includes a scale, a sensor, and a light source. The scale includes first and second pattern areas. The first pattern area includes first patterns periodically arranged in first and second directions. The second pattern area includes second patterns periodically arranged in the first and second directions. The sensor is configured to move relative to the scale in the first direction and includes first, second, third, and fourth sensing areas. The first and third sensing areas are configured to sense changes of the first pattern area in the first and second directions respectively. The second and fourth sensing areas are configured to sense changes of the second pattern area in the first and second directions respectively. The light source is configured to emit light toward the scale.

The present application relates to the field of optical communication technology, disclose a kind of wavelength tuning method based on external cavity double micro-ring laser, it solves the technical problems such as the large data quantity, long time consumption, easy to miss target wavelength and unable to simultaneously optimize side mode rejection ratio and line width etc. core performance index of existing traversal method to carry out wavelength tuning.The present application realizes the accurate analysis of the relationship between driving voltage and wavelength by establishing physical model and quadratic fitting relationship, avoids full-range current scanning;Utilize vernier effect under the wavelength selection mechanism of double micro-ring resonance peak alignment, ensure that output wavelength is accurately locked to protocol wavelength, performance is superior to approximate lookup table method;Through theoretical derivation and experimental calibration, the driving voltage corresponding to any reference wavelength can be predicted, which adapts to the individual differences of different micro-rings and realizes personalized rapid tuning;A large number of trial-and-error processes are transferred to simulation and theoretical calculation, which reduces the occupation and energy consumption of physical test equipment and improves production efficiency and production line resource utilization.