112 results about "Multimode fibre" patented technology

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 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.

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.

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 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.

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 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 invention relates to a microscope comprising a light source, an illumination beam path for directing excitation light into a sample area, a detector for detecting emission light emitted by a sample, a detection beam path with a microscope objective for directing the emission light onto the detector, and a control unit for evaluating the emission light detected by the detector. The microscope is characterized in that the illumination beam path for providing an intermediate image plane includes at least one relay optic, that the illumination beam path includes a multimode optical fiber, and that an output end of the multimode optical fiber is arranged in or near the intermediate image plane. The invention also relates to a method for microscopy.

The invention belongs to the technical field of fiber bragg grating wireless sensing, and particularly discloses a wireless passive optical fiber sensing system and a control method thereof. The system comprises a demodulation module, a passive fiber grating sensing module and a first optical transceiver module, the passive fiber bragg grating sensing module comprises a fiber bragg grating sensor and a second optical transceiver module which are connected in sequence; the first optical transceiver module and the second optical transceiver module receive optical signals through a multimode optical fiber of which one end is a conical lens; the first light receiving and transmitting module and the second light receiving and transmitting module are oppositely arranged in a preset distance range, and a transmitting light path and a receiving light path which are not coaxial are formed after light beams are aligned; the emitting light path receives the detection light output by the demodulation module and transmits the detection light to the passive fiber grating sensing module; the receiving optical path receives the sensing optical signal transmitted by the passive fiber grating sensing module and transmits the sensing optical signal to the demodulation module for demodulation by the demodulation module. According to the invention, the system detection efficiency can be greatly improved while the detection safety is improved.

This invention belongs to the field of optical fiber communication and optical imaging technology, specifically a spatial mask optimization method for speckle reconstruction in multimode optical fibers. The method includes: using a laser to output monochromatic coherent light, modulating the image to be transmitted onto the incident light field through a spatial light modulator, injecting it into a multimode optical fiber, and acquiring a speckle image at the fiber output end; calculating a normalized radial cumulative energy function on the speckle image to determine the truncation radius; constructing a spatial mask, including a hard mask, a soft mask, and a multi-ring weighted mask; multiplying the mask pixel-by-pixel with the speckle image to obtain a preprocessed speckle image, which is used as input to a downstream image reconstruction model; periodically recalculating the normalized radial cumulative energy function and automatically updating the truncation radius to adapt to changes in fiber state. This invention effectively improves training efficiency while maintaining reconstruction accuracy by removing low signal-to-noise ratio peripheral regions; it can automatically track changes in fiber state and adapt to environmental drift during engineering deployment.

An all-fiber inline optical tap adopts a configuration of a side-pump signal-and-pump combiner with a double-clad fiber (DCF) and one or more multimode fibers (MMFs). DCF comprises a first cladding and a coupling portion, whereas each of MMFs comprises a taper portion fused around the coupling portion. MMFs are configured to extract a part of combined optical energy and a part of an optical signal leaking in the first cladding of DCF with a sampled optical power proportional to a fiber laser power in a propagating direction. By pre-selecting a proper taper slope of the taper portion and an embedded depth the MMFs fused and embedded in the coupling portion, the all-fiber inline optical tap can be built with a customized ratio used in fiber laser power monitoring, diagnostics, and controls of a fiber laser system.

The application provides a 1.7-micron-band single-frequency fiber laser based on a composite glass optical fiber, which comprises a long linear cavity, and the long linear cavity comprises, in sequence, a high-reflection Bragg grating (3), a composite glass optical fiber (4), a saturable absorber (5) and a low-reflection Bragg grating (6). 3+ The composite glass optical fiber is a multimode optical fiber, has a double-clad structure, and the core is Tb 3+ The inner cladding is Tm 3+ The outer cladding is undoped rare earth composite glass. The 1.7-micron-band single-frequency fiber laser is compact in structure, high in efficiency and narrow in line width, and can be applied to the fields of gas sensing, precision measurement, laser radar and the like.

This invention discloses a bridge bending detection method based on a lightweight multi-scale sparse gating network, relating to the field of bridge structural health monitoring. The method includes: acquiring multimode fiber speckle images corresponding to different bending states of the bridge and preprocessing them to obtain standardized speckle images; obtaining an initial feature map based on a lightweight multi-scale sparse gating network through initial convolutional layers and max pooling layers; extracting and fusing bending-sensitive features through a multi-level multi-scale feature fusion module to obtain a multi-scale fused feature map; using a learnable sparse gating module for feature selection to obtain a sparse enhanced feature map; modeling global dependencies through a global context enhancement module to obtain a globally enhanced feature map; and inputting the globally enhanced feature map into a dual-task prediction module to output the corresponding result. This method achieves synchronous, lightweight, and high-precision detection of bridge bending degree and location, effectively decoupling the problem of multi-parameter cross-sensitivity.

The invention provides a condition generation GAN compensation method for optical fiber disturbance and imaging application, relates to the field of multimode optical fiber information transmission and image reconstruction, and solves the technical problems of speckle rotation and noise interference in an optical fiber random swing scene due to lack of a feature extraction mechanism. The method comprises the following steps: constructing hybrid dense blocks HDBs by adopting a dense connection architecture, and extracting global rotation features in an original speckle image; and inputting the global rotation feature into an extrusion excitation block SEBs to obtain an optimized speckle rotation global feature. The generator is constructed using encoder and decoder architectures. And inputting the optimized speckle rotation global features into a generator to form an original-reconstructed image pair. And generating an adversarial network GAN-HDSE framework, and outputting a discrimination probability sensitive to spatial resolution. And training the network by using the multi-scene dynamic interference speckle data set, and outputting a high-fidelity original image. The multi-mode optical fiber is used in the multi-mode optical fiber information transmission and image reconstruction process.

The invention discloses a multi-source single-output green light beacon laser for space application, which is characterized in that a light source part comprises two butterfly-shaped packaging laser devices which are cold backups for each other, the butterfly-shaped packaging laser devices are solid laser devices packaged in butterfly-shaped shells, each butterfly-shaped packaging laser device comprises a semiconductor pumping chip, a shaping optical fiber, a laser crystal Nd: YVO4 and a frequency doubling crystal PPLN, and green light of 532nm is generated; in the filtering and beam combining light path part, 532nm green light emitted by each light source is respectively provided with a half-wave plate for adjusting the polarization direction, is combined into the same light path through a polarization splitting prism, is filtered by a light filter, enters a multimode optical fiber through an optical fiber collimator, and is divided into two paths through an optical fiber coupler; one path is used for monitoring the output power and health state of the laser in real time, and the other path is used as main beacon light. The problem of performance reduction caused by the overheating phenomenon of the light-emitting unit is effectively solved, high-power output can be kept for a long time, and meanwhile the overall light weight and flexibility of the laser are considered.

An optical apparatus (200) includes an outer jacket (230), common cladding (220), and multiple single mode fiber cores (210). The common cladding (220) is within the outer jacket (230) and is used as multimode fiber such that the outer jacket (230) clads the common cladding (220). The single mode fiber cores (210) are within the common cladding (220) such that the common cladding (220) clads the plurality of single mode fiber cores (210).

This application provides a ring beam shaping system based on multimode fiber mode interferometry, comprising an input unit, a mode conversion unit, and an output unit. The input unit is a single-mode fiber with a first fiber parameter, used to input a Gaussian beam. The mode conversion unit is a multimode fiber with a second fiber parameter, connected to the single-mode fiber via fusion splicing, used to excite and interfere with higher-order modes. The output unit is a ring-core fiber with a third fiber parameter, connected to the mode conversion unit via fusion splicing, used to maintain and output a ring beam distribution. The core diameters of the single-mode fiber, multimode fiber, and ring-core fiber increase progressively, as do the NA values ​​of the single-mode fiber, multimode fiber, and ring-core fiber. This system achieves high-quality ring beam output through a simple, flexible, and efficient all-fiber structure, significantly reducing cost and complexity, improving stability and reliability, and has broad application prospects.

The utility model provides a kind of SPR sensor based on MZI structure, and the sensor includes multimode fiber, quartz capillary, gold film and chitosan functional film.Two multimode fibers middle fusion quartz capillary forms MZI, quartz capillary is filled with thermosensitive material, quartz capillary is plated with gold film, and the outside of gold film is coated with a layer of chitosan functional film.The sensor uses the thermosensitive material in quartz capillary to cause MZI resonance spectrum drift with temperature change to measure temperature, and uses chitosan functional film and copper ion chelation to cause SPR resonance spectrum drift to measure concentration.The utility model realizes the double-parameter simultaneous measurement of copper ion concentration and temperature by composite structure design, with the characteristics of compact structure and high sensitivity.

A multimode optical fiber having a core region. The core region includes silica, has an outer radius r1, and has a maximum relative refractive index of about 1.5% or less. Further, the multimode optical fiber is configured to have an effective bandwidth of about 4.7 GHz-Km or more for an excited portion of the core region having a diameter greater than 50 microns, the effective bandwidth being at a wavelength in a range of about 800 to about 1370 nm.

A homogeneous laser illumination system for microscopy applications, based on the use of multimode optical fibers (MMF), is described. The system's operating principle relies on the superposition of dynamic speckle patterns generated from several multimode fibers. These patterns are created by applying random, high-frequency perturbations (tens of kilohertz) induced by a piezoelectric actuator that perturbs the optical fibers. The superposition of these patterns reduces illumination contrast, achieving a uniform light distribution across the field of view (FOV). The system's modularity and adaptability allow for its integration into existing microscopy setups. Furthermore, it can be configured to operate with standard commercial objective lenses, including immersion lenses, and adjusted to reduce photobleaching in fluorescent samples.The system uses multimode optical fibers and requires no additional infrastructure to manage vibrations or mechanical noise. It is suitable for fluorescence microscopy and has been successfully tested with wavelengths across the visible spectrum. The system enhances the illuminated area and optimizes the generation of homogeneous light patterns, providing a high-performance and efficient solution for obtaining high-quality images in microscopic studies.