18 results about "Single mode fiber coupling" patented technology

The invention relates to the technical field of neutral atom quantum computing, in particular to a manufacturing method and device of a spatial optical coupling device. The method comprises the following steps: melting and stretching one end of a large-core-diameter optical fiber to form a conical optical fiber section through an optical fiber tapering technology; and the other end of the large-core-diameter optical fiber receives spatial light, so that when an optical signal passes through the conical optical fiber section, high-order mode light is cut off and leaked into the cladding, and fundamental mode light can be transmitted into the single-mode optical fiber to realize single-mode light output. A large-core-diameter optical fiber is used for replacing a single-mode optical fiber to couple spatial light, the alignment tolerance of the spatial light coupling stage is improved, the coupling efficiency can be improved to about 95%, the coupling efficiency of all light beams can be improved to about 70% under the condition of multi-light-beam coupling, and the requirement for mechanical adjustment precision and the system cost are reduced; and a large-core-diameter optical fiber is transited to a single-mode optical fiber through an optical fiber tapering technology, so that high-quality single-mode light output is realized.

An optical system includes an optical transmitter coupled to a signal transmitting path, an optical receiver coupled to a signal receiving path, and a phase plate array configured to couple a first portion of an optical beam to a first single-mode fiber and to couple other portions of the optical beam to a plurality of other single-mode fibers. The first portion of the optical beam corresponds to a fundamental optical mode and the other portions corresponds to a plurality of higher-order optical modes. The first single-mode fiber is coupled to both the signal transmitting path and the signal receiving path using an optical circulator, and the plurality of other single-mode fibers are coupled to the signal receiving path.

The invention relates to quantum key distribution, in particular to a space-based quantum key distribution system and a QKD transmitter, the space-based quantum key distribution system takes an FPGA as a control core and comprises an electronic module and an optical module, and the electronic module is responsible for converting key information provided by a QKD processor into a modulation signal and realizing dynamic coding of a quantum state; the optical module encodes a quantum state under the action of the modulation signal, regulates and controls the quantum pulse intensity to a single photon level, and finally outputs the quantum pulse intensity to a laser communication terminal of a satellite platform to be transmitted to an optical ground station; the optical ground station comprises an uplink system and a downlink system, the uplink system provides a stable and reliable beacon for the satellite platform, and the downlink system dynamically detects and compensates wavefront distortion based on a high-frequency closed-loop wavefront correction mechanism, counteracts the influence of atmospheric disturbance on light beam quality in real time and performs single-mode optical fiber coupling; according to the technical scheme provided by the invention, the defect that space-based quantum key distribution is difficult to accurately and efficiently carry out can be effectively overcome.

The application discloses a kind of high-pressure silicon carbide power module internal partial discharge detection system and method, including broadband light source, optical fiber isolator, optical fiber circulator, single-mode 3x3 optical fiber coupler, delay optical fiber, first single-mode 1x2 optical fiber coupler, optical fiber sensor, second single-mode 1x2 optical fiber coupler, optical power meter, first single-mode optical fiber, second single-mode optical fiber, third single-mode optical fiber, fourth single-mode optical fiber, fifth single-mode optical fiber, sixth single-mode optical fiber, optical fiber adapter, optical fiber adapter, balanced photoelectric detector, analog low-pass filter, data acquisition card and host computer.The application can adjust the size of optical fiber sensor itself for different frequency band partial discharge signals to obtain the detection signal-to-noise ratio that meets the demand;Meanwhile, the application will not be affected by electromagnetic interference, and can be applied in high-pressure field.

The invention provides a broadband light interference type cantilever beam inherent frequency detection device and method with high precision and strong anti-interference performance. The broadband light interference type cantilever beam inherent frequency detection device comprises near-infrared broadband light, a single-mode optical fiber coupler, a gradient refractive index lens, a single-point spectrometer and an upper computer, the light source radiates near-infrared broadband light with bandwidth, and the near-infrared broadband light enters the single-mode optical fiber coupler through the light inlet. The near-infrared broadband light is transmitted to the probe light outlet through the single-mode optical fiber coupler, and is divided into reference light and probe light after passing through the gradient refractive index lens; the probe light is focused to the surface of the cantilever beam through the graded index lens and is backscattered by the cantilever beam to be coupled with the reference light reflected by the end face of the graded index lens in the single-mode optical fiber coupler to form interference; and the interference signal is transmitted by the single-mode optical fiber coupler and is input into the single-point spectrometer through the light return port. According to the technical scheme, high precision can be kept while large-amplitude vibration measurement is achieved, and the accuracy and reliability of inherent frequency measurement of the cantilever beam are remarkably improved.

The application discloses a single-mode optical fiber adaptive coupling method in a turbulent environment, and relates to the fields of single-mode optical fiber coupling, automatic control, fiber lasers and fiber imaging. The application analyzes the relationship between the coupling efficiency and the offset distance, simplifies the relationship curve into a Gaussian model, and is used for subsequent adaptive updating of the closed-loop gain rate. In addition, the gradient direction generated randomly in the traditional control method is changed into all-directional disturbance, and the gradient direction accurately and quickly approaching the target value is calculated. By projecting the two-dimensional micro-disturbance into one-dimensional space, using the least square method, the step length and the gradient direction required for iteration are automatically solved, so that the focused light spot is quickly captured and tracked. Compared with the traditional control method, the application guarantees the convergence speed of the algorithm, effectively improves the convergence stability, makes the system have a wider effective correction area, and improves the closed-loop control bandwidth range of the disturbance correction.

The invention discloses a quantitative phase imaging system and method based on Bessel beam illumination, and the method comprises the steps: enabling laser output by a laser device to be coupled through a beam splitting 1 * 2 single-mode optical fiber through a light source and a beam splitting module, filtering a high-order mode, and splitting the laser into object light and reference light; through a Bessel beam generation module, object light is collimated by a short-focus lens to form a plane wave, the plane wave is incident to a spatial light modulator, phase distribution of an axis prism is loaded, the plane wave is modulated into a Bessel beam, the Bessel beam is subjected to beam contraction through an objective lens and a tube lens in sequence, the Bessel beam passes through a scattering medium, an effective area covered by a central main lobe serves as an imaging area, a sample to be detected is irradiated, and the target object is detected. Outputting central main lobe object light; the reference light is collimated into a plane wave through a short-focus lens, the incident angle of the plane wave is adjusted through a reflector, then the intensity of the reference light is adjusted through a linear polarizer, and interference fringes with the optimal contrast are obtained; and the signal acquisition and processing module converts data extracted from the interference fringes into three-dimensional height information of the sample, so that high-precision quantitative phase imaging is realized.

The present invention belongs to the technical field of single-mode fiber coupling and laser confocal imaging, and particularly relates to a single-mode fiber coupling apparatus and method in a laser confocal optical path. The apparatus comprises a coupling assembly and a bracket set. The coupling assembly comprises a laser, wherein an output end of the laser is connected to one end of a single-mode fiber I, and the other end of the single-mode fiber I is connected to an input end of a collimator; an output end of the collimator refracts light to a coupler through a dichroic mirror for coupling, and the coupler is mounted at a refraction end of the dichroic mirror; a CCD camera is mounted at a transmission end of the dichroic mirror for monitoring; and an output end of the coupler is connected to one end of a single-mode fiber II, and the other end of the single-mode fiber II is connected to an optical power meter. The bracket set comprises a collimator bracket, a dichroic mirror bracket and a coupler bracket, which respectively clamp the collimator, the dichroic mirror and the coupler. The present invention utilizes a real-time imaging function of a CCD camera to realize the accurate alignment of laser beams, thereby improving the coupling efficiency of single-mode fibers.

The invention discloses a polarization modulator, a polarized light generation method, a storage medium and electronic equipment, and relates to the technical field of polarization modulation. A polarization maintaining optical fiber in a polarization modulator is coupled with a first electro-optical modulator, and an included angle between target optical axes of the polarization maintaining optical fiber and the first electro-optical modulator is close to 45 degrees; the first electro-optical modulator and the second electro-optical modulator are in cascade coupling, and the rotation angle of the optical axis of the second electro-optical modulator relative to the optical axis of the first electro-optical modulator is close to 45 degrees; and the second electro-optical modulator is coupled with the single-mode optical fiber. The polarization state modulator provided by the invention has the advantages of miniaturization, high integration level and relatively low cost, and can efficiently and conveniently generate polarized light in various vibration directions.

The present disclosure relates to an optical edge coupler or spot-size converter (SSC) that includes multiple juxtaposed layers of auxiliary waveguides with underlying silicon-on-insulator (SOI) waveguides. In one embodiment, the SSC includes two waveguide layers, each having four auxiliary waveguides, including two inner auxiliary waveguides interposed between two outer auxiliary waveguides. The waveguide layers collectively include at least two sections. In the first section, each auxiliary waveguide diverges in the direction of light propagation. In the second section, each outer auxiliary waveguide converges toward each other. The SOI waveguides partially overlap the first section and completely overlap and extend beyond the second section. The SSC facilitates coupling of light from a flat-cleaved standard single-mode fiber with a mode field diameter of 10.4 μm at 1550 nm into the SOI waveguide, which has low loss and flat-band response at C-band and L-band communication wavelengths.

The present disclosure relates to hollow core fiber to single mode fiber connectors. A hollow core fiber (HCF) and single mode fiber (SMF) coupling system, comprising: a HCF located in a first inner housing; a SMF that has been exposed to a thermal expansion core (TEC) process and is located in a second inner housing, wherein the SMF is in series with the HCF in the first inner housing; and the first inner housing and the second inner housing.

The application provides a micro-nano optical fiber array-based photothermal spectrum gas detection device and method, and the device comprises a light emitting component, a first single-mode optical fiber coupler, a micro-nano optical fiber array gas chamber, an optical narrowband filter, an optical frequency shift module and a light conversion component; the light emitting component is connected with the optical frequency shift module and the light conversion component; the light emitting component is sequentially connected with the first single-mode optical fiber coupler, the micro-nano optical fiber array gas chamber, the optical narrowband filter and the light conversion component; wherein the micro-nano optical fiber array gas chamber comprises a micro-nano optical fiber sensing array structure. The micro-nano optical fiber is used as a core sensing element, which can realize high-sensitivity and rapid-response gas sensing, and can be mass-produced at a low cost.

The application discloses a wavefront-sensorless staged hybrid optimization wavefront correction method, and relates to the technical field of adaptive optical optimization control, in particular to a wavefront-sensorless staged hybrid optimization wavefront correction method.The method comprises the following steps: building a wavefront-sensorless adaptive optical system for laser communication; performing first-stage trust-region derivative-free optimization in a low-dimensional mode space composed of a plurality of Zernike mode coefficients; setting a joint switching mechanism; when the first-stage trust-region derivative-free optimization meets the joint switching mechanism, outputting first-stage optimal mode coefficients and corresponding optimal single-mode fiber coupling power; constructing an initial control vector for second-stage SPGD optimization based on the first-stage optimal mode coefficients; performing full-dimensional voltage space SPGD optimization based on the initial control vector, outputting a historical optimal drive voltage vector, and using the historical optimal drive voltage vector for wavefront correction.

This invention discloses a multi-core fiber ring resonator nested single-longitudinal-mode narrow-linewidth fiber laser and its linewidth measurement method. The laser includes a pump source, a combiner, an erbium-doped fiber, a Butterworth filter, a first single-mode bare fiber, a first four-core bare fiber, a second four-core bare fiber, a four-core three-ring nested coupled fiber resonator ring, a second single-mode bare fiber, a polarization controller, a first single-mode fiber coupler, a fiber isolator, a spectrometer, and an optical power meter. This invention, through a fiber laser structure with a four-core three-ring nested coupled fiber resonator ring and a temperature-controlled stable Butterworth filter inside the ring, can simultaneously achieve single-longitudinal-mode, narrow-linewidth, and power-enhanced output while simplifying structural design.

The invention provides a total temperature and total pressure integrated sensor based on a sapphire fiber grating, the sensor adopts a sapphire fiber + multimode fiber + single-mode fiber coupling structure, compared with the sapphire fiber directly coupled with the single-mode fiber, the coupling efficiency is remarkably improved, the single-mode fiber structure adopted at the rear end can effectively filter out the influence of a high-order mode, and the overall temperature and total pressure of the sensor are improved. Low-order mode transmission is realized, and transmission loss and bending loss are reduced. According to the technical scheme, the technical problems that in the prior art, the high-temperature measurement range is insufficient, the sensing structure is prone to damage, and the total temperature and the total pressure cannot be synchronously collected are solved.

The present disclosure relates to a photonic edge coupler or spot-size converter (SSC) comprising multiple juxtaposed layers of auxiliary waveguides with an underneath silicon-on-insulator (SOI) waveguide. In an embodiment, an SSC comprises two waveguide layers each having four auxiliary waveguides including two inner auxiliary waveguides interposed between two outer auxiliary waveguides. The waveguide layers collectively include at least two sections. In a first section, each auxiliary waveguide widens in a light propagation direction. In a second section, each outer auxiliary waveguide converges towards each other. The SOI waveguide partially overlaps the first section, fully overlaps the second section, and extends therebeyond. The SSC facilitates coupling of light from a flat-cleaved standard single-mode fiber with mode-field diameter of 10.4 µm at 1550 nm to an SOI waveguide with low loss and flat band response in the C-band and L-band telecommunication wavelengths.

The application provides a mode field adaptation gradient structure for coupling of a sapphire optical fiber and a single-mode optical fiber, comprising an input end, a gradient structure body and an output end; the input end is used for coupling connection with an output end of a single-mode optical fiber, and the output end is used for coupling connection with an input end of a sapphire optical fiber; the gradient structure body comprises a gradient cladding layer and a gradient core; the diameter of the gradient cladding layer presents a first nonlinear gradient rule along an axial direction, and the diameter of the gradient core presents a second nonlinear gradient rule along the axial direction; the first nonlinear gradient rule and the second nonlinear gradient rule are independent of each other, so that the gradient cladding layer and the gradient core adopt independent nonlinear change profiles. The application reduces loss of mode field matching of the three, shortens the length of the mode field adaptation gradient structure on the basis of satisfying adiabatic mode conversion, and makes the device more compact and reliable.

This invention relates to a passively mode-locked fiber laser based on a nanograting-based polarizer and its operating method, comprising: a pump source, a wavelength division multiplexer, two polarization controllers, two nanograting lines, a single-mode optical coupler, a polarization-independent isolator, and a section of gain fiber; the pump source provides 976nm pump light to the ring cavity; the wavelength division multiplexer inputs the 976nm pump light into the ring cavity; the two nanograting lines act as an equivalent of a bulk polarizer and, together with the two polarization controllers, achieve the NPR effect; the single-mode fiber coupler couples out 10% of the resonant light within the cavity and serves as the laser's output light; the polarization-independent isolator ensures unidirectional operation of the resonant light within the ring cavity; and a section of gain fiber converts the 976nm pump light into 1032nm resonant light. This invention is the first of its kind and represents a novel laser system, which will play a very important role in subsequent research and development.