182 results about "Multimode fibre" patented technology

The invention relates to an optical fiber hydrogen sensor based on a silver film-nanowire hole array structure and a preparation method thereof in the field of photochemical sensors. The optical fiber hydrogen sensor comprises a multimode optical fiber, and a sensing area is formed on the multimode optical fiber; the sensing area is formed by stripping a coating layer with a preset length from the multimode optical fiber, thinning the optical fiber in the area, plating a silver film on the surface of the thinned optical fiber, and adsorbing a nanowire hole array structure which is sequentially and vertically arranged on the surface of the silver film in a liquid level self-assembly manner; the nanowire hole array is of a metal-medium-metal (MIM) structure, a gold-palladium nanowire array is arranged at the bottom, an intermediate medium layer is made of aluminum oxide, and a silver film with a hole array in any shape is arranged at the top. When light is transmitted to a sensing area from a fiber core of the multimode optical fiber, the light and a metal silver film can excite a surface plasmon resonance (SPR) effect, meanwhile, an MIM structure formed by a gold-palladium nanowire, an aluminum oxide dielectric layer and a porous silver film serves as an optical coupling antenna through a local surface plasmon resonance (LSPR) effect at the edge of a top hole, and the optical coupling antenna is used for transmitting the light to the sensing area. Light energy is efficiently converged and excited in an extremely bound gap plasmon (Gap Plasmon) in an aluminum oxide dielectric layer, so that far-unconventional electromagnetic field enhancement is generated in a sensing core area, and the sensitivity of the sensor is greatly improved.

The invention relates to the technical field of bionic touch sensors, in particular to a touch pain sense sensor based on double-layer heterogeneous optical fiber sharpness perception and a preparation method. The touch pain sense sensor comprises an SGS-MZI structure which is formed by welding a single-mode optical fiber, a step type multimode optical fiber and a gradual change type multimode optical fiber and is used for realizing shallow touch pressure detection; the MNF structure is located under the SGS-MZI structure; the MNF structure is a non-adiabatic conical structure obtained by fused biconical taper of a single-mode fiber, and is used for realizing deep contact pressure and sharpness detection; the middle supporting layer is located between the SGS-MZI structure and the MNF structure; and the SGS-MZI structure and the MNF structure are fixedly arranged on the top surface and the bottom surface of the middle supporting layer respectively. According to the invention, through a double-layer heterogeneous structure based on the sandwich structure multimode fiber Mach-Zehnder interferometer (MZI) and the MNF, sharpness identification and touch pain perception functions are realized, so that the detection performance of the bionic touch sensor is improved.

The utility model relates to the technical field of optical devices, in particular to a multimode short-distance optical device, which comprises a circuit board, a light emitting element, a light receiving element, a cushion block, a thermoelectric refrigerating unit and an optical lens. The light emitting element and the light receiving element are both arranged on the cold face of the thermoelectric refrigerating unit, the light emitting element is a vertical cavity surface emitting laser, and the optical lens is arranged on the emergent light path of the light emitting element and the incident light path of the light receiving element. And the reflector is used for reflecting and focusing the emitted light of the light emitting element into the multimode optical fiber and reflecting and focusing the incident light of the multimode optical fiber into the light receiving element. According to the utility model, a flexible assembly form is provided, the temperature of the heating element can be effectively controlled, and the problems of low efficiency and low precision in the aging process are solved; in addition, by arranging the light paths on the same stable structure, stable support is provided for the light paths, and the stability of the light paths is improved.

The invention provides a photoacoustic pumping imaging system based on pulse laser phase energy correction. The opto-acoustic pumping imaging system based on pulse laser phase energy correction comprises a 128-channel array ultrasonic acquisition system, two OPO tunable lasers and a digital delay pulse generator which form the opto-acoustic pumping imaging system, a 128 array element linear ultrasonic transducer and a 2 * 2 multimode fiber bundle; and a pulse laser phase energy correction system which needs to monitor and correct the phase of the laser pulse. The opto-acoustic pumping imaging system based on pulse laser phase energy correction provided by the invention realizes accurate phase correction and energy normalization based on precise synchronization of two acquisition systems, so that the system can significantly reduce the fluctuation of TTD data, improve the stability and reliability of results, improve the acquisition speed and signal-to-noise ratio of the system, and improve the imaging quality of the system. The detection limit is reduced.

The present application relates to a kind of end sensor and tactile feedback type interventional catheter and its autonomous navigation method, the end sensor includes hemispherical light waveguide, compound eye array lens, multimode optical fiber and optical fiber image bundle, the front end of the optical fiber image bundle is equipped with compound eye array lens, the front of the compound eye array lens is equipped with hemispherical light waveguide, its bottom is placed four multimode optical fibers along circumference and certain incident angle is made into light waveguide, so that optical fiber end surface and light waveguide bottom surface coincide;The tactile feedback type interventional catheter is built-in the end sensor, based on the wide-angle imaging function provided by compound eye array lens and the force feedback function provided by light waveguide contact causes light leakage, can autonomously navigate and provide accurate force feedback and contact point position, need not guide wire as guiding device, can directly intervene blood vessel and in the intervention process, real-time feedback catheter and blood vessel wall contact mechanics information and position information, and change catheter intervention direction as required.

The invention relates to a broadband bending-resistant multimode optical fiber and a preparation method thereof, the refractive index profile of a core layer is in a gradually-changed parabola shape, the distribution index alpha is 1.95-2.65, the radius R1 of the core layer is 12-35 microns, the delta 1max is 0.9%-1.4%, the relative refractive index difference delta 1min at the R1 position of the edge of the core layer is-0.16%--0.06%, cladding layers comprise an inner cladding layer, a first sunken cladding layer, a second sunken cladding layer and an outer cladding layer from inside to outside in sequence, the inner cladding layer is sequentially provided with a first inner cladding layer and a second inner cladding layer from inside to outside, the single-side width (R4-R3) of the first sunken cladding layer is 1.5-9.0 [mu] m, delta 4 is-1.1%--0.60%, the single-side width (R5-R4) of the second sunken cladding layer is 1.0-3.0 [mu] m, delta 5 is-1.0%--0.55%, the radius R6 of the outer cladding layer is 60-65 [mu] m, and delta 6 is-0.12-0.12%. The core cladding is reasonable in structural design, has the excellent characteristics of high bandwidth, strong bending resistance and low attenuation, and is high in transmission efficiency and excellent in long-term stability and reliability.

The invention discloses an optical fiber single-pixel imaging method and device based on sparse optimization and neural network fusion, and the method comprises the steps: constructing a collimation illumination system, carrying out the spatial modulation of incident light, introducing a collimation illumination mechanism, and obtaining a spatial speckle illumination light field of a multimode optical fiber; performing sparsity extraction analysis on the spatial speckle illumination light field by using a sparse optimization algorithm, removing a high redundancy mode, and selecting a speckle illumination mode with the lowest cross correlation; a speckle illumination mode after sparse optimization is used as input, a neural network model constructed based on a soft threshold iterative algorithm is trained, and an optical fiber single-pixel image reconstruction model is established; performing sparse optimization speckle illumination on a target object, acquiring corresponding total light intensity response data, inputting the data into the trained optical fiber single-pixel image reconstruction model, realizing image reconstruction and outputting a final target image; the method has anti-defocusing capability and anti-disturbance robustness, and can still keep good optical fiber single-pixel image reconstruction performance under the condition of low sampling rate.

The invention discloses a surface plasmon resonance (SPR) hydrogen sensor based on an Ag / PDMS / Pt-WO3 multilayer structure. The SPR hydrogen sensor is characterized by comprising a halogen lamp light source, two sections of multimode optical fibers, a spectrometer and an SPR hydrogen sensing head, wherein the SPR hydrogen sensing head is composed of a different-core structure formed by multimode-single-mode-multimode optical fibers, a silver film, PDMS (polydimethylsiloxane) and Pt-WO3 (platinum-tungsten trioxide). The SPR hydrogen sensor based on the Ag / PDMS / Pt-WO3 multi-layer structure, which is simple to prepare, high in sensitivity and capable of being repeatedly used for a long time, is provided aiming at the defects that an existing optical fiber SPR hydrogen sensor is low in sensitivity and complex in device manufacturing, and PdH is changed from an alpha phase to a beta phase when Pd is used as a hydrogen sensitive material, so that the use of the device is influenced, and the like. When the hydrogen concentration is increased, the Pt-WO3 reacts with the hydrogen to generate heat, so that the refractive index of the PDMS film is changed, the SPR resonance spectrum is moved, and the hydrogen concentration is obtained by observing the offset of the PDMS film. The high refractive index sensitivity of SPR is brought into full play by utilizing the high refractive index change of PDMS, so that high-precision detection of hydrogen leakage is realized.

A system and a method for regulating a living tissue cell are provided. The system includes: a laser source module, a modulation module, an optical fiber module, an imaging module, and a control module. The modulation module is configured for modulating the received first laser based on a preset modulation strategy to determine a regulation light and modulating the received second laser based on the preset modulation strategy to determine an imaging light, wherein the preset modulation strategy refers to a strategy for wavefront modulation of the first laser and the second laser. The regulation light or the imaging light is output to the deep area of living tissue through the multimode optical fiber in the optical fiber module.

The invention discloses an MXene-based dual-channel cascade coreless optical fiber SPR sensor and application thereof, the sensor is formed by cascading a multimode optical fiber with two sections of coreless optical fibers, the NCF area of the channel 1 is only coated with a gold film, and the NCF area of the channel 2 is coated with a gold-cysteamine-MXene composite film. Theoretical analysis shows that when the NCF lengths of the channel 1 and the channel 2 are 5 mm and 12 mm respectively, the visibility of formants is optimal, and the distance between the formants can be increased by increasing the thickness of MXene. Experiments show that in the refractive index range of 1.333-1.366, the optimal number of layers of MXene is four, at the moment, the RI sensitivity of a channel 1 and the RI sensitivity of a channel 2 reach 1894.27 nm / RIU and 4001.48 nm / RIU respectively, and the FOM is 16.86 RIU <-1 > and 32.99 RIU <-1 > respectively. The device is simple in structure, low in cost and convenient to operate, and has good application potential in the field of two-parameter biochemical sensing.

The invention discloses a satellite-ground laser communication atmospheric channel compensation system and method. Relates to the technical field of satellite-ground laser communication, in particular to a satellite-ground laser communication atmospheric channel compensation system and method. Through structural coupling and parameter matching, deep collaboration of the multimode fiber and the MPLC is realized, and the optical signal coupling efficiency in the turbulent environment is remarkably improved on the premise of reducing the complexity, power consumption and cost of the system. In the system, a receiving module captures and focuses a multi-mode optical signal emitted by a satellite to a transmission connection module through a coupling lens group; the transmission connection module receives and transmits the multi-mode optical signal to the multi-mode input end of the MPLC through the fiber core of the multi-mode optical fiber; and the modal screening module decomposes a multi-modal optical signal received by the multi-modal input end of the MPLC through the MPLC optical mode demultiplexing module to obtain a plurality of modal fundamental modes, and outputs the fundamental modes through the MPLC single-mode output end.

This invention belongs to the field of fiber optic sensing and relates to a method based on WS 2 A temperature sensor based on all-fiber fluorescence intensity comprises a single-mode fiber, a three-hole grapefruit fiber, and a multimode fiber connected in sequence; the three-hole grapefruit fiber has three air holes, in which WS is deposited. 2 The multimode fiber output end is equipped with a mounting base, on which a filter is mounted. This invention utilizes WS... 2 Assembled within a three-hole optical fiber, with single-mode and multi-mode fibers fused together at both ends, this sealed structure effectively isolates the sensor from external air, preventing contact between the outside air and the two-dimensional material on the inner wall of the fiber during heating. This slows down the decomposition of transition metal sulfides, significantly improving the fluorescent sensor's ability to detect high temperatures and extending its lifespan. The sensor itself and its detection system are coupled and output via optical fiber, eliminating the need for external spatial light or optical modulation.

The invention relates to a miniaturized near-infrared spectrometer imaging system, which relates to the field of near-infrared spectrometers, and comprises a light source module, a sample light generation module, an optical fiber coupler, an optical fiber F-P filter, a photoelectric detector and a multimode optical fiber, light rays generated by the light source module can irradiate a sample through the sample light ray generation module and generate sample light rays, the optical fiber coupler and the optical fiber F-P filter are connected through multimode optical fibers, the optical fiber F-P filter and the photoelectric detector are connected through multimode optical fibers, and the optical fiber coupler receives sample optical fibers; and the signal is transmitted to the photoelectric detector through the multimode optical fiber, the optical fiber F-P filter and the multimode optical fiber. According to the invention, the baseline drift and noise of the spectrum are reduced, the accuracy of the spectrum is improved, the size is smaller, and the weight is lighter.

This optical amplifier comprises: a rare-earth-doped optical fiber; an excitation light coupler that inputs signal light and excitation light to the rare-earth-doped optical fiber; a multimode excitation light source that outputs the excitation light to a multimode fiber; and a spatial multiplexing optical fiber that is connected to the multimode fiber, that introduces the excitation light into the excitation light coupler, and that has two or more spatial channels.

The present invention relates to the field of optical imaging technology, and in particular to a multimode optical fiber imaging method, system and device based on deep learning. The method comprises: loading a hologram selected after mask processing into an optical modulator so that the light beam output by the multimode optical fiber realizes mask scanning imaging, and the hologram is a hologram used to realize phase modulation of the optical modulator; collecting an image obtained by mask scanning imaging, and restoring the image based on a pre-trained deep learning network model. In the present invention, the optical modulator is modulated by the hologram selected after mask processing, so that when the light beam modulated by the optical modulator passes through the multimode optical fiber to image the sample to be tested, mask scanning imaging can be realized, that is, the imaging speed is improved and the light flux is reduced by reducing the number of sampling points. At the same time, a deep learning network model is further used for restoration, which provides a data basis for the subsequent accurate analysis of the sample to be tested.

This invention discloses an energy homogenization control system for multimode fiber laser lenses, relating to the field of high-power multimode fiber laser technology. The invention achieves online monitoring of the beam spot behind the lens through a beam sampling unit and an acquisition unit, quantifies the energy distribution uniformity through a uniformity evaluation unit, generates adjustment commands through a control decision unit combining feedforward and feedback strategies, actively regulates the beam energy distribution through a homogenization execution unit, and finally ensures the safe and stable operation of the system through a safety protection unit. This achieves closed-loop homogenization control of the beam energy distribution during multimode fiber laser processing, improving the stability and consistency of processing quality, reducing processing defects caused by beam fluctuations, and enhancing anomaly identification and safety protection capabilities.

The application belongs to the technical field of wavelength measurement, and is especially a high-resolution speckle wavelength measurement device and method. The device comprises a shell, a first optical fiber incident port and a second optical fiber incident port are arranged on the outer wall of the shell, an optical switch, a light splitting coupler, a calibration light source and a test light path are arranged in the shell, and the test light path is composed of a multimode optical fiber, an optical fiber mode enhancement device and a surface array detector. The application enhances the coupling and phase delay between different modes by applying mechanical disturbance to the scattering medium, increases the number of excited modes, and solves the problems that the resolution of the speckle wavelength meter is limited by the light path length of the transmission medium and the insufficient information density of the speckle per unit area. The method can improve the wavelength resolution, and effectively improve the sampling speed of the speckle wavelength meter by reducing the size of the photosensitive camera target surface.

The utility model relates to a kind of optical fiber sensing technology, specifically a kind of high-isolation raman wave division multiplexer for DTS, including first wave division multiplexer, second wave division multiplexer, erbium-doped fiber and 980 / 1550nm fusion taper pumping optical wave division multiplexer;First wave division multiplexer, second wave division multiplexer all include single-fiber collimator and double-fiber collimator, and optical fiber type is multimode OM3 optical fiber;Double-fiber collimator has one optical fiber as same optical fiber, so that there is no fusion point between first wave division multiplexer, second wave division multiplexer;Another optical fiber of the double-fiber collimator of second wave division multiplexer uses erbium-doped fiber, so that there is no fusion point between second wave division multiplexer, erbium-doped fiber;Fusion taper pumping optical wave division multiplexer is completely made using HI 1060 optical fiber fusion taper process, and 980nm and 1550nm wavelength are separated;Erbium-doped fiber other end is fused with fusion taper wave division multiplexer main end;Remaining optical fiber is used for port output / input.

The present application relates to the technical field of perovskite photoelectric devices and flat plate optical waveguide, and particularly relates to a method for monitoring the quality and uniformity of perovskite thin film. The method comprises: providing a device to be measured comprising at least a glass substrate and a perovskite layer; coupling light from a wide-spectrum light source into the glass substrate through a multimode optical fiber to excite a loss mode resonance (LMR) effect; collecting a transmission spectrum after a polarizer through a spectrometer; extracting the peak position, intensity and half-peak width of the LMR characteristic peak. The red shift of the peak position indicates thickness change, the intensity decay and the half-peak width broadening indicate quality decline. Multi-point scanning can evaluate uniformity. The present application does not require vacuum equipment, is non-destructive, fast, low-cost, can be integrated into the production line, and solves the problem that the existing detection method cannot meet the needs of large-scale production.

A sample observation device (1) comprising: a light source (10); an objective lens (13); a multimode optical fiber (15); an optical dispersion element (18) configured to allow angular dispersion of the light transmitted by the objective lens as a function of wavelength; an image sensor (19) configured to form an image of the light dispersed by the optical dispersion element; and a processing unit (30) configured to accumulate the intensity detected on pixels along each isofreference line, so as to obtain a frequency spectrum, taking into account the curved shape of each isofreference line. Figure 6A.

The invention relates to a multimode optical fiber (1) with an optical axis (2). The multimode optical fiber has a single fiber core (11) surrounded by a cladding (12) and comprises a proximal end (3) for connection to an endoscopic system (13) and a distal end (4) for introduction into a sample (14). The distal end (4) has a light transmission surface (5), which extends substantially parallel to the optical axis (2) and is designed to transmit light radially in relation to the optical axis (2). The light transmission surface (5) is a substantially flat surface, a spherical segment surface or a paraboloid segment surface, and is a boundary surface of the fiber core (11). In addition, the distal end (4) has a light reflection surface (6), which extends such that the optical axis (2) at the distal end (4), a normal to the light transmission surface (5) and a normal to the light reflection surface (6) lie substantially in one plane and an angle between the light reflection surface (6) and the optical axis (2) is between 30° and 60°. In addition, the invention relates to an endoscopic system (13) for examining a sample (14) and to a method for examining a sample (14) by means of an endoscopic system (13).

The application discloses a high-power single-mode linear polarization Raman fiber laser based on a multimode optical fiber, and is characterized in that: a Raman gain medium of the laser is a single-clad circularly symmetric step-index distribution large-core multimode optical fiber; a base mode diameter of the step-index large-core multimode optical fiber is more than 65% of a core diameter; a Bragg fiber grating is inscribed in the core of the multimode optical fiber by using a femtosecond laser direct writing technology; a long axis of the grating region is coincided with a base mode field supported by the multimode optical fiber in a radial direction in space and length; the grating forms selective optical feedback only to the base mode in the cavity; a grating region with a difference between the long axis and the short axis forms selective feedback to one polarization state of the base mode; thus, the multimode optical fiber Raman laser effectively suppresses generation of mode instability at a high power level through active mode cleaning, and finally realizes near-diffraction-limited single-mode, high linear polarization and high-power Raman fiber laser output.

The present invention relates to a DC electric field sensing system with a rotating structure, so as to achieve accurately measuring the DC electric field. The system includes a laser, a rotating structure, and a detector, wherein the rotating structure includes a single-mode fiber-optic slip ring, a collimator lens, a polarizer, a quarter-wave plate, a crystal, and a multi-mode fiber-optic slip ring. Experimental results show that the technical solution has advantages such as fast response, and strong resistance to electromagnetic interference, and makes it possible to inhibit beam deviation, achieve beam collimation, and enable high-precision measurement, by using the rotating structure and the fiber-optic slip ring.

The invention discloses an image reconstruction method and imaging system based on multimode fiber holography and polarization coding, and the method comprises the following steps: S1, outputting a laser light source, eliminating the reflected light through an isolator, and carrying out the light beam expansion through a first lens and a second lens; s2, dividing the expanded light beam into a reference arm and a signal arm by using an optical splitter; s3, in the signal arm, generating a hologram containing spatial position information through a DMD, dynamically switching polarization states through an optical relay device, and forming holographic light field distribution of different polarization states in a three-dimensional space; s4, the modulated multi-polarized light field is coupled through a microscope objective to enter a multimode optical fiber; s5, the optical fiber output end forms a speckle pattern carrying polarization information through the achromatic lens group; and S6, collecting a speckle pattern through a camera, and realizing holographic image reconstruction by adopting a U-Net neural network. According to the invention, high-fidelity image transmission and reconstruction in the multimode optical fiber are realized.

The invention discloses a photoacoustic endoscopic imaging probe and system based on a surrounding type transparent transducer array, and belongs to the technical field of photoacoustic endoscopic imaging equipment. The photoacoustic endoscopic imaging probe comprises a shell, and a multimode optical fiber, a diverging lens, an axicon and a plurality of transparent transducers which are fixedly connected with the shell, the multimode optical fiber is configured to receive and transmit the light spot; the diverging lens is arranged on an emergent light path of the multimode optical fiber, and the diverging lens is configured to receive the light spots and amplify the field of view; the cone mirror is arranged on an emergent light path of the diverging lens, and the cone mirror is configured to reflect the light spots amplified by the view field to multiple emergent directions of the side surface of the cone mirror; the plurality of transparent transducers are arranged on the side surface of the conical mirror, the plurality of transparent transducers and the plurality of emergent directions are arranged in a one-to-one correspondence manner, and the transparent transducers are configured to transmit light beams, focus the light beams on the tissue sample and receive photoacoustic signals generated by the tissue sample. The system has the advantages of high acquisition efficiency, high imaging speed, high signal-to-noise ratio, miniaturization and high expansibility.

This invention provides a battery temperature measurement method and device based on multimode optical fiber, belonging to the field of battery optical fiber sensing technology. This method aims to solve the problems of limited monitoring range, difficulty in achieving distributed measurement, and high system complexity and cost of existing battery temperature measurement technologies. The technical solution involves deploying multimode optical fiber on or inside the battery. During battery charging and discharging, optical signals are injected into the optical fiber, and the output speckle image is acquired, along with the battery's voltage and current data. Subsequently, the speckle image and electrical data are input into a preset temperature calibration model for processing, thereby obtaining the battery's temperature information. The advantages are: distributed temperature measurement with spatial resolution on or inside the battery can be achieved using only a single optical fiber; the structure is simple, the cost is low, and it is resistant to electromagnetic interference; combined with deep learning models and battery operating condition data, the accuracy and intelligence of temperature measurement are significantly improved, providing a reliable means for battery safety monitoring.

The hydrogen sensor based on temperature compensation comprises a pair of multimode optical fibers, a single-mode optical fiber, a first plasma resonance structure and a second plasma resonance structure, and a protective layer is arranged outside the single-mode optical fiber; the first plasma resonance structure coats at least part of the protective layer from the first end of the single-mode optical fiber; the second plasma resonance structure coats at least part of the protective layer from the second end of the single-mode optical fiber; wherein the first plasma resonance structure comprises a first resonance layer and a first temperature sensing layer which are arranged from inside to outside, and the second plasma resonance structure comprises a second resonance layer, a second temperature sensing layer and a heating layer which are arranged from inside to outside; the first resonance layer and the second resonance layer are used for absorbing hydrogen in the environment and can generate a surface plasma resonance effect under the action of an optical signal, and the heating layer is a hydrogen sensitive material capable of reacting with hydrogen to release heat. Through the arrangement, the hydrogen concentration detection accuracy of the hydrogen sensor is improved.

The application provides a kind of sub-aperture mosaic spectral calibration detection device and its detection method, wherein the detection device includes: broadband light source, wavelength division multiplexing device, coupler, integrating sphere and spectrometer;Detection device is used to detect large aperture telescope system, and telescope system includes primary mirror and secondary mirror;Broadband light source is used to emit broadband light beam to wavelength division multiplexing device, and wavelength division multiplexing device is used to select the frequency band of broadband light beam, and the incident light beam is transmitted to the pupil of telescope system through coupler, and is incident to focal plane after being reflected twice in primary mirror and secondary mirror of telescope system, and integrating sphere is arranged at the focal plane of telescope system, and the outgoing light beam is transmitted to spectrometer by multimode optical fiber to obtain the actual measured spectral data T (i). The application selects spectrum by wavelength division multiplexing device, and the response generated by different spectrum, finally realizes the splicing detection of system through the cooperation of three domains of space domain, time domain and frequency domain.

The application relates to a high-bandwidth bending-insensitive multi-mode optical fiber which can be used for data communication and automobile communication, comprising a core layer and a cladding layer, the core layer has a parabolic refractive index profile, and the cladding layer comprises a first inner cladding layer, a second inner cladding layer, a sunken cladding layer and an outer cladding layer from inside to outside; the core layer distribution index alpha1 is 1.9-2.1, the core layer radius R1 is 12-28 mu m, the core layer center maximum relative refractive index difference Delta0 is 0.8%-1.2%, the relative refractive index difference Delta1 at the core layer edge R1 is-0.03%-0.03%, the width (R2-R1) of the first inner cladding layer is 0.4-3 mu m, the relative refractive index difference Delta2 at the outer side edge of the first inner cladding layer is-0.3%--0.04%, and the first inner cladding layer refractive index profile is a power exponential function distribution, and the width (R3-R2) of the second inner cladding layer is 0.5-4 mu m. The application realizes the optimization of optical transmission bandwidth performance.

The present invention discloses a multi-parameter demodulation method for optical fiber speckle based on parallel deep learning, which relates to the field of optical fiber sensing. The method comprises the following steps: applying a combined perturbation to a multimode optical fiber, synchronously collecting speckle images and corresponding curvature, vibration intensity, and position coordinate labels, and constructing a multi-parameter mapping dataset; dynamically dividing the dataset into subsets based on computing power, and independently training a feature extraction subnetwork with each subset to generate a pre-trained weight set; constructing a parallel neural network architecture, loading and freezing the pre-trained weight set, and training a fusion classification network to obtain an optimized fusion classification network; inputting the speckle image to be measured into the optimized fusion classification network, and outputting the corresponding parameter demodulation results. Through the parallel deep learning architecture and the reuse mechanism of pre-trained weights, this method achieves high-precision synchronous demodulation of curvature, vibration, and position coordinates in optical fiber speckle, combining strong anti-interference performance with efficient computing power utilization.