47 results about "Spectral purity" patented technology

The invention discloses a marine plankton hyperspectral imaging detection system, relates to the technical field of spectrum detection, and is used for solving the problem of poor spectrum classification and recognition in a water body environment. According to the method, the hyperspectral image and the environmental disturbance parameters are synchronously acquired, and the disturbance mapping sequence is constructed, so that accurate alignment between the image and disturbance is realized. A disturbance contribution weight matrix is constructed based on a dominant wave band, pixel-level spectrum stripping is carried out, a plankton purification spectrum is extracted, the spectrum purity and the recognition accuracy are improved, and a spectrum abnormal drift region is precisely recognized in combination with derivative spectrum change and image texture features; a coupling relation between the drift region and background disturbance is further established, a dynamic interference factor map is generated, and identification model parameters are dynamically adjusted, so that the identification stability and classification accuracy of the system in a complex interference environment are improved, and the method is suitable for multi-scene marine ecological monitoring.

The invention discloses an urban black and odorous water quality judgment method based on a hyperspectral remote sensing data deep learning model, and particularly relates to the technical field of water quality judgment. Water quality monitoring data of a plurality of sampling points and corresponding hyperspectral remote sensing images are obtained, a water body dynamic change sensitivity index of each sampling point is calculated based on historical water quality change conditions, an end member extraction algorithm is adopted to analyze spectrum mixing conditions of remote sensing pixels, and the spectral purity confidence coefficient of the remote sensing pixels is calculated; the method comprises the following steps of: acquiring a plurality of samples, generating a credibility grade of each sample, removing or reducing the weight of low-credibility samples, introducing a time sequence remote sensing image for the samples in a high water body dynamic change sensitivity index region, and reconstructing remote sensing features through interpolation to recover a spectrum state at a real sampling moment, so that the reliability of remote sensing-actual measurement fusion data is remarkably improved; and the judgment capability of the model in a water quality rapid change or interference complex region is enhanced, and the remote sensing intelligent identification of the urban black and odorous water body with higher precision and stronger robustness is realized.

The invention discloses a method for preparing a powder sample of an X-ray photoelectron spectrometer, and relates to the technical field of X-ray photoelectron spectrometers, which comprises the following steps of: weighing a powder sample to be detected, putting the powder sample into a crucible, and then putting the crucible filled with the powder sample into a drying box for drying treatment; the method comprises the following steps: putting a sample and spectroscopically pure into an agate grinding body, fully grinding and uniformly mixing, sieving for later use after grinding, weighing the sieved powder, and dividing into a plurality of equal parts; preparing a tabletting mold, placing a powder sample in the tabletting mold, and grinding and uniformly mixing the sample again through an upper mold; according to the method disclosed by the invention, the spectral purity is proportionally added into the powder sample, so that the number display intensity of the powder sample during detection can be improved, and the final detection effect is further improved; according to the invention, the sample is sheeted by using the pressing machine, so that the stability of the formed sample can be improved, the loosening phenomenon in the transfer and detection process can be avoided, and meanwhile, the flatness of the surface of the sample can be ensured, so that the accuracy of detection data can be ensured.

The invention discloses a single-frequency pulse laser with high spectral purity. The single-frequency pulse laser comprises a pump light processing system, an active resonant cavity, a gain medium, a light pulse generating device and a nonlinear optical modulator, the gain medium is arranged on an emergent light path of an input mirror of the active resonant cavity; the optical pulse generating device and the nonlinear optical modulator are both placed in the active resonant cavity, the optical pulse generating device is used for adjusting the loss of the active resonant cavity so as to form pulsed light, and the nonlinear optical modulator is used for rapidly increasing the loss difference between different modes in the resonant cavity so as to generate high-spectral-purity single-frequency pulse laser; the nonlinear optical modulator comprises a nonlinear crystal, and the nonlinear crystal is arranged on an optical path between the gain medium and the output mirror of the active resonant cavity. According to the invention, the nonlinear crystal, the optical pulse generation device and the gain medium are utilized to enable a secondary mode to be rapidly annihilated within a short time, so that the single-frequency pulse laser output with high spectral purity is realized.

A septum configured to transmit extreme ultraviolet radiation, the septum including a nanostructure configured to absorb deep ultraviolet radiation, and a method for forming the septum. The diaphragm may form part of an EUV lithographic apparatus, for example as part of a spectral purity filter, pellicle assembly, or dynamic airlock assembly.

The invention provides a thulium-doped optical fiber with high spectral purity and a preparation method thereof, and the thulium-doped optical fiber with high spectral purity adopts a profile design that the refractive index of a main gain layer follows linear gradual change distribution of a linear function and the refractive index of a secondary gain layer is constant, so that the mode distribution of an optical fiber fundamental mode is precisely overlapped with the main gain layer; the secondary gain layer is located at the lowest point of the waveguide refractive index; the design can effectively solve the problem that in the prior art, due to the limitation of the MCVD technology, the doping concentration difference of the main gain layer and the secondary gain layer is caused, and then the optimal emission wavelengths of different gain areas are inconsistent. Besides, depending on the bending loss difference of the main gain layer and the secondary gain layer, on the premise that the gain efficiency of the optical fiber is not sacrificed, effective separation of emission wavelengths of the main gain layer and the secondary gain layer can be achieved through bending regulation, the target wavelength of the main gain layer is reserved, and the non-target wavelength of the secondary gain layer is filtered out. And finally, the spectral purity of the thulium-doped optical fiber is improved.

The application provides a semiconductor structure and a preparation method thereof and a semiconductor laser, and relates to the field of lasers. The semiconductor structure comprises a substrate, a first waveguide layer, a resonant structure and a second waveguide layer; the first waveguide layer is arranged on the surface of the substrate along the thickness direction; the resonant structure comprises an active region, an input layer and an output layer; the active region, the input layer and the output layer are arranged on the side of the first waveguide layer away from the substrate; in a plane parallel to the plane in which the substrate is located, the input layer and the output layer are located on the two sides of the active region, and the output layer is arranged obliquely; in the direction away from the substrate, the output layer is away from the input layer; the second waveguide layer is arranged on the side of the resonant structure away from the surface of the first waveguide layer, and the second waveguide layer is connected with the resonant structure. The application can reduce the possibility of interference effect between reflected light and the light field in the FP cavity, make the longitudinal mode output of the semiconductor structure more stable, and improve the spectral purity of the semiconductor structure.

The application discloses a LiNbO3-based periodic curved three-busbar structure acoustic wave resonator and a preparation method thereof, which comprises a substrate, a piezoelectric film layer arranged on the substrate, an interdigital electrode layer arranged on the piezoelectric film layer, a release hole arranged on the piezoelectric film layer, and a cavity arranged in the substrate, wherein the interdigital electrode layer is provided with symmetrically arranged interdigital electrodes, and two interdigital electrodes on the same side are connected by three parallel periodic curved busbars. The transverse excitation bulk acoustic resonator (XBAR) based on the curved three-busbar structure can effectively suppress the transverse high-order stray mode, significantly weaken the ripple in the passband, suppress the additional acoustic energy loss caused by the parasitic mode, improve the flatness and stability of the frequency response, and improve the signal transmission performance of the device. Compared with the traditional XBAR with the parallel busbar structure, the structure can effectively avoid the excitation of other non-target acoustic modes during the resonance process, thereby improving the spectral purity of the device and increasing the Q value by about 4 times compared with the traditional XBAR.

The invention relates to a polarization entangled photon pair, in particular to a polarization entangled photon pair generation method and device based on a mixed framework, and the method comprises the steps: bidirectional excitation: a dual-wavelength polarization beam splitter (PBS) divides laser into two beams of light which are horizontally and vertically polarized, and the two beams of light are transmitted in the clockwise CW direction and the anticlockwise CCW direction of a Sagnac interference ring respectively; photon pair generation: the two beams of light are coupled into a waveguide, and in the waveguide, horizontal polarized light propagating along the clockwise CW direction and vertical polarized light propagating along the anticlockwise CCW direction respectively generate a pair of photon pairs; quantum interference and entanglement generation: after the two paths of photon pairs are output from the waveguide, the two paths of photon pairs converge at a dual-wavelength polarization beam splitter (PBS) again, the amplitudes of the two paths of photon pairs are coherently superposed by regulating and controlling the phase in a Sagnac interference ring, and an ideal polarization entanglement singlet state is generated at two output ports of the dual-wavelength polarization beam splitter (PBS); according to the invention, the defect that high brightness, high efficiency, high entanglement fidelity, high spectral purity and high photon indistinguishability cannot be synchronously realized can be effectively overcome.

The invention relates to the technical field of plasma EUV, in particular to an extreme ultraviolet light output method, device and equipment based on an electrodeless pinch system. The extreme ultraviolet light output method comprises the following steps: pre-ionizing lithium gas in an electrodeless pinch system to generate a first plasma group; completely ionizing the first plasma cluster to generate a second plasma cluster so as to generate an extreme ultraviolet beam; the light beam output assembly outputs extreme ultraviolet light beams, and the light beam output assembly outputting the extreme ultraviolet light beams is kept heated. The technical problems that the EUV radiation conversion efficiency is low, the spectral purity is poor, and the particle debris pollution of the tin target is serious are solved. The extreme ultraviolet light output device and the computer equipment have the same beneficial effects as the extreme ultraviolet light output method.

The invention discloses a photo-production microwave method based on a light injection semiconductor laser. An output optical signal of injecting the light in the single-period oscillation state into the semiconductor laser is transmitted through an optical fiber to generate an electric feedback signal, the electric feedback signal is used for performing electro-optical modulation on the injected light, and finally, the output optical signal is subjected to photoelectric detection to obtain a low-noise photo-generated microwave signal; the electric feedback signal generation method comprises the following steps: firstly, converting a transmitted output optical signal into an electric signal and dividing the electric signal into two paths; performing frequency division on the first electric signal to obtain a frequency-divided electric signal; performing feedback control adjustment on the phase of the second path of electric signal by taking the constant phase difference between the frequency division electric signal and a reference signal with the same frequency as a control target; and combining the second path of electric signal after feedback control adjustment with the reference signal into one path to obtain the electric feedback signal. The invention further discloses a photo-generated microwave device based on the light injection semiconductor laser. The frequency spectrum purity and the frequency stability of the signal can be effectively improved.

A reflective spectral purity filter (SPF) for extreme ultraviolet (EUV) light includes a substrate having a reflective surface and an angle of incidence of at least 60 degrees, and a blazed diffraction grating formed on the substrate, the blazed diffraction grating having a grating pitch and blaze angle (fixed or variable) configured to simultaneously diffract incident EUV light into a higher-order diffraction angle and confine out-of-band (OOB) light to a Oth order reflection angle to angularly separate the EUV light and the OOB light. An imaging system including the reflective SPF, the imaging system having a field of view (FOV) configured to collect the spatially filtered EUV light and reject the OOB light based on angular separation of the lights.

The invention relates to the technical field of lasers, in particular to a semiconductor laser which comprises a first laser module, a first light beam conversion lens, a first slow axis conversion lens, a first volume Bragg grating and a half-wave plate which are sequentially arranged along a first light beam path. The second laser module, the second light beam conversion lens, the second slow axis conversion lens and the second volume Bragg grating are sequentially arranged along a second light beam path; the polarization splitting prism is located at the intersection point of the first light beam path and the second light beam path; the third volume Bragg grating is located on the side, away from the half-wave plate, of the polarization splitting prism; wherein the diffraction efficiency of the first volume Bragg grating is lower than that of the third volume Bragg grating, and the central wavelength of the first volume Bragg grating is the same as that of the third volume Bragg grating. According to the invention, the multi-mode resonance effect can be suppressed, the side-mode suppression ratio can be improved, and the spectral purity after the line width is narrowed can be improved.

The invention discloses a control method of a multi-piezoelectric ceramic vibration exciter parallel combination system, and relates to the technical field of vibration control and piezoelectric driving, and the method comprises the steps: synchronously collecting the working time sequence waveform of each vibration exciter and the energy consumption flow data of the system, calibrating the waveform, and carrying out the spectrum purity analysis of the energy consumption data to extract the fundamental wave and harmonic wave components. And performing time-frequency domain alignment fusion on the calibrated time sequence waveform and the energy consumption spectrum component, and constructing a system state fusion tensor. And based on the tensor, identifying phase coherence and energy coupling strength among excitation units in the system, and further deducing a global vibration mode and a local instability risk area of the system. And making a dynamic balance control plan according to a deduction result, redistributing output energy of each vibration exciter and coordinating action phases of the vibration exciters. According to the invention, accurate diagnosis and risk prediction of the internal interaction state of the parallel vibration exciter system are realized, and the stability and controllability of cooperative work of the system are improved.

The invention relates to the technical field of semiconductor lasers, in particular to an electric control high-speed tunable laser based on a spiral lithium niobate waveguide. The substrate opening is formed in the upper end surface of the substrate; the gain chip is arranged in the opening of the substrate; the lithium niobate film optical waveguide is arranged on the upper end surface of the substrate; the device further comprises a collimating lens, an optical etalon and a reflector. The collimating lens, the optical etalon and the reflector are sequentially arranged on the right side of the laser output end of the lithium niobate film optical waveguide in the laser output direction. The invention has the following beneficial effects: 1, high-speed electric control tuning; 2, the adjusting range is wide; 3, compact integrated design; 4, the spectral purity is high.

The invention discloses an ultra-narrow linewidth continuous wave low-noise fiber seed laser generation system. The system comprises a semiconductor pumping source, a single-mode wavelength division multiplexer, a phase shift Bragg fiber grating, a polarization-maintaining fiber circulator, a scattering fiber, a polarization-maintaining tunable fiber grating, a polarization-maintaining isolator, a dispersion compensation fiber, a semiconductor optical amplifier and a polarization-maintaining 12 fiber coupler. The system generates single-frequency laser through the phase shift Bragg fiber grating, realizes line width narrowing by combining distributed Bragg feedback based on Rayleigh scattering, improves output power by using the semiconductor optical amplifier, and effectively suppresses noise by combining the dispersion compensation fiber. According to the scheme, the ultra-narrow linewidth continuous wave low-noise optical fiber seed laser with high stability and high spectral purity can be realized, and the ultra-narrow linewidth continuous wave low-noise optical fiber seed laser has important application value, is suitable for a front-end light source of a high-quality optical fiber laser, and provides key support for the fields of precision measurement, coherent communication and the like.

Techniques disclosed herein relate to photon sources with high spectral purity and high brightness. In one embodiment, a photon-pair source includes a pump waveguide, a first resonator coupled to the pump waveguide to couple pump photons from the pump waveguide into the first resonator, a second resonator coupled to the first resonator, and an output waveguide coupled to the second resonator. The second resonator is configured to convert the pump photons into photon pairs. The second resonator and the first resonator are configured to cause a coupling-induced resonance splitting in the second resonator or the first resonator. The second resonator and the output waveguide are configured to couple the photon pairs from the second resonator into the output waveguide. In some embodiments, the photo-pair source includes one or more tuners for tuning at least one of the first resonator or the second resonator.

Provided are systems and methods for registration and carrying out fine image adjustments of aerial or satellite images to obtain super registered images. Also provided are systems and methods for registration where resampling is minimized or avoided to reduce, minimize, or prevent spectral degradation.

Techniques disclosed herein relate to photon sources with high spectral purity and high brightness. In one embodiment, a photon-pair source includes a pump waveguide, a first resonator coupled to the pump waveguide to couple pump photons from the pump waveguide into the first resonator, a second resonator coupled to the first resonator, and an output waveguide coupled to the second resonator. The second resonator is configured to convert the pump photons into photon pairs. The second resonator and the first resonator are configured to cause a coupling-induced resonance splitting in the second resonator or the first resonator. The second resonator and the output waveguide are configured to couple the photon pairs from the second resonator into the output waveguide. In some embodiments, the photo-pair source includes one or more tuners for tuning at least one of the first resonator or the second resonator.

Provided are systems and methods for registration and carrying out fine image adjustments of aerial or satellite images to obtain super registered images. Also provided are systems and methods for registration where resampling is minimized or avoided to reduce, minimize, or prevent spectral degradation.

The utility model discloses a backlight module and electronic equipment, and the backlight module comprises a light guide plate layer which comprises a light guide plate; the light source layer is arranged below the light guide plate layer; and the quantum dot film layer is arranged above the light guide plate layer. The backlight module provided by the embodiment of the utility model is higher in spectral purity.

The invention provides a manufacturing method of a resonant cavity light-emitting diode, which comprises the following steps of: performing epitaxial manufacturing on a first type semiconductor layer in a window with a smaller area, so that the crystal quality is improved, and the reliability of a device is improved; an active layer, a second-type semiconductor layer and a first reflecting layer are sequentially manufactured in an epitaxial mode and inversely arranged on the bearing substrate, the area of the first-type semiconductor layer is gradually reduced in the direction away from the bearing substrate, a second reflecting layer is manufactured on the inclined wall of the first-type semiconductor layer, and the first reflecting layer and the second reflecting layer form a resonant cavity; light is reflected for multiple times in the resonant cavity, so that the light resonance effect is improved, the light has a narrower wavelength peak, and the spectral purity is improved; the upper surface, far away from the bearing substrate, of the first type semiconductor layer is a light outlet, the area of the light outlet is the smallest, and the directivity and collimation of light emitting can be improved.

The invention discloses a hyperspectral image unmixing method for double-end-member set non-negative tensor decomposition based on space structure maintenance, and belongs to the technical field of hyperspectral remote sensing image analysis. The method mainly comprises the following steps of: approximately representing hyperspectral image data as a product of an end member matrix and an abundance matrix and then adding a noise tensor; under the condition of a fixed end member matrix, a self-adaptive Sobel weighted space regular term is introduced for the abundance matrix, and the abundance matrix is iteratively updated through gradient weighting coefficients in the horizontal and vertical directions; and under the condition of a fixed abundance matrix, introducing truncation type low-rank-sparse constraint to the decomposed end member matrix, and alternately optimizing and updating the pure end member matrix and the variant component matrix by adopting an iterative reweighting strategy. According to the method, the continuity of a space structure is kept during unmixing, and meanwhile, a pure part and a variation part of an end member can be separated, so that the spectral purity, the physical interpretability and the anti-noise capability of an unmixing result are improved.

The invention provides a semiconductor structure, a preparation method thereof and a semiconductor laser, and relates to the field of lasers. The semiconductor structure comprises a substrate, a first waveguide layer, a resonant structure and a second waveguide layer. The first waveguide layer is arranged on the surface of the substrate in the thickness direction; the resonant structure comprises an active region, an input layer and an output layer, and the active region, the input layer and the output layer are arranged on the side, away from the substrate, of the first waveguide layer; in a plane parallel to the substrate, the input layer and the output layer are positioned on two sides of the active region, the output layer is obliquely arranged, and the output layer is far away from the input layer in a direction far away from the substrate; the second waveguide layer is arranged on the resonant structure away from the first waveguide surface and is connected with the resonant structure. According to the semiconductor structure, the possibility of generating an interference effect between reflected light and a light field in an FP cavity can be reduced, so that the longitudinal mode output of the semiconductor structure is more stable, and the spectral purity of the half-layer conductor structure is improved.

The application provides a frequency-adjustable ultra-stable laser generation method and a laser system based on modulation sideband frequency locking, which lock first-order sideband light of electro-optical modulation laser to the resonance frequency of an ultra-stable optical resonant cavity, and then utilize frequency synthesis technology to ensure constant modulation-demodulation phase relationship in the frequency modulation process of the electro-optical crystal, so as to realize the ultra-stable laser with frequency locking function. With the application, short-term ultra-stable laser with a frequency adjustment range of 100 MHz and high spectral purity can be obtained through simple optical structure and control process, so as to meet the demand of precise spectral measurement and quantum communication and other application scenarios for ultra-stable laser signals with a large adjustment range.

The invention discloses a GaN-based vertical micro-cavity Micro-LED based on electroplating technology and a preparation method thereof. The micro-cavity Micro-LED of the invention has a narrow half-height width of light emission and good light emission directionality. By thinning the chip thickness and using the metal reflector of the p-GaN layer (5) and the dielectric film reflector of the n-GaN layer as the end face of the resonant cavity, a vertical resonant micro-cavity structure is formed, which will suppress the light emission from the side wall and improve the directionality of the front light emission, thereby reducing the crosstalk effect between adjacent pixels of the Micro-LED display. At the same time, the resonant micro-cavity structure will select a specific wavelength to narrow its light emission spectrum and increase the spectral purity, which will be beneficial to improving the threshold of the Micro-LED display. The vertical structure Micro-LED of the invention has a large active area and less light absorption by n-GaN; the current expansion is good, the voltage is low, the current density is small, and it has advantages in light efficiency, saturation current, and long-term reliability; secondly, the Cu substrate has good electrical conductivity and thermal conductivity, and the chip thermal resistance is small.

The invention relates to a source (1) for generating squeezed states for Gaussian boson sampling, comprising a laser (2), an optical component (3) and a waveguide (4), wherein the laser (2) is optically connected to the optical component (3) for transmitting the laser beam emitted by the laser, the optical component (3) is optically connected to the waveguide (4) for transmitting the laser beam, wherein the optical component (3) is configured to couple the laser beam into the waveguide (4) such that a spatial mode of order ≥ 1 is excited in the waveguide (4), and the waveguide (4) has a nonlinear medium, such that a squeezed signal-idler state having signal and idler beams is generated in the waveguide (4) with the spatial mode.In this way, a source for generating squeezed states for Gaussian boson sampling with improved spectral purity and brightness is provided.

The invention provides a chromium telluride germanide saturable absorber-based bright and dark soliton fiber laser, which relates to the technical field of fiber lasers and comprises a pump light source module for providing pump light and coupling the pump light into a laser resonant cavity through a wavelength division multiplexer; and the laser resonant cavity module comprises a wavelength division multiplexer, an erbium-doped fiber, a polarization controller, a polarization independent isolator, a single-mode fiber, a chromium telluride germanium saturable absorber and an output coupler which jointly form a laser oscillation and amplification environment. Parameters are dynamically adjusted through fuzzy control and monitored and analyzed in real time, comprehensive monitoring, evaluation and optimization of the laser performance are achieved in combination with the performance evaluation and optimization module, and the stability, efficiency and spectral purity of the laser are improved.

A reflective spectral purity filter (SPF) for extreme ultraviolet (EUV) light includes a substrate having a reflective surface and an angle of incidence of at least 60 degrees, and a blazed diffraction grating formed on the substrate, the blazed diffraction grating having a grating pitch and blaze angle (fixed or variable) configured to simultaneously diffract incident EUV light into a higher-order diffraction angle and confine out-of-band (OOB) light to a 0th order reflection angle to angularly separate the EUV light and the OOB light. An imaging system including the reflective SPF, the imaging system having a field of view (FOV) configured to collect the spatially filtered EUV light and reject the OOB light based on angular separation of the lights.

This invention proposes a narrow-emission ultraviolet gallium sulfide quantum dot material and its synthesis method, belonging to the field of semiconductor quantum dot material technology. The method employs a one-pot synthesis strategy and introduces a specific passivating agent into the reaction system. By precisely controlling the reaction conditions and the amount of passivating agent, high-purity ultraviolet-emitting gallium sulfide quantum dots with an emission peak at 392 nm and a half-maximum width at half-maximum (HWHM) of 34 nm were successfully prepared. This synthesis method significantly reduces the HWHM of gallium sulfide quantum dots and improves their spectral purity. This invention provides an effective method for preparing ultraviolet environmentally friendly quantum dots with high color purity, demonstrating great application potential in cutting-edge fields such as lighting and full-color displays.