100 results about "Diffraction effect" patented technology

The invention belongs to the technical field of metal crack detection, and discloses a metal microcrack ultrasonic detection method, which comprises the following modules: an ultrahigh frequency composite array probe with a center frequency dynamic adjustable range of 5-50 MHz; the dual-mode excitation and receiving module is used for independently generating a pulse reflection mode excitation signal and a diffraction mode chirp frequency modulation signal; the phase-controlled synthetic aperture dynamic focusing module is used for realizing + / -60-degree deflection and sub-wavelength level focusing of acoustic beams; the nonlinear harmonic enhancement module is used for exciting a crack nonlinear effect by superposing 1-2MHz fundamental waves; and a time-space-frequency three-domain data fusion module. According to the method, signal-to-noise ratio collapse caused by the diffraction effect in a traditional method is overcome, more importantly, the system has low-frequency penetrability and high-frequency resolution at the same time due to 80%-120% of broadband coverage of chirp frequency modulation signals, the diffraction signal gain is increased by 20 dB or above, a near-surface blind area is compressed to be within 0.2 mm, and the system can be applied to the field of radar imaging. And the core pain point of missing detection of the near-surface microcracks of the thin-wall component is solved.

The invention provides a deep tunnel micro-seismic source positioning method and system, and relates to the technical field of micro-seismic source positioning, and the method comprises the steps: obtaining first information, second information and third information; performing particle swarm initialization according to the first information, the second information and the third information to obtain an initial particle swarm parameter set; performing diffraction path judgment according to the particle swarm parameter set to obtain a judgment result of a diffraction occurrence condition; calculating a minimum diffraction path according to a diffraction identification result to obtain a shortest path length set; according to the shortest path length set and the second information, carrying out wave velocity inversion to obtain an optimal wave velocity value and a seismic source spatial position; and according to the optimal wave velocity value and the seismic source spatial position, carrying out seismic moment calculation to obtain seismic moment data. According to the method, accurate modeling and path compensation of an elastic wave diffraction effect are realized, so that propagation path deviation caused by existence of a goaf is effectively eliminated, and the accuracy and reliability of deep tunnel micro-seismic source positioning are remarkably improved.

An optical waveguide device and a preparation method therefor, and a near-eye display device. The optical waveguide device (1) comprises at least one optical waveguide (10). The optical waveguide (10) comprises: a waveguide sheet (11), which is used for making light beams transmit in the waveguide sheet (11) in a total reflection manner, wherein the waveguide sheet (11) has a coupling-in region (B) and at least two coupling-out regions (A); a coupling-in grating (12), which is arranged in the coupling-in region (B) and is used for coupling the light beams into the waveguide sheet (11); and at least two coupling-out gratings (13), which are correspondingly arranged in the at least two coupling-out regions (A) on a one-to-one basis, and are used for coupling out the light beams, which are transmitted in the waveguide sheet (11) in a total reflection manner, wherein the light intensities of the light beams coupled out by the at least two coupling-out gratings (13) are identical. The present application can improve the exit pupil uniformity of the optical waveguide device (1), thereby improving the visual experience of users, and also reducing the research and development costs incurred by the use of masks and the impact caused by diffraction effects.

The present invention relates to a detection device for the diffraction effect correction coefficient of a solar irradiance absolute radiometer, comprising a solar simulation light source, an aperture diaphragm, a lens, a light shielding disc and a light intensity detector; the solar simulation light source illuminates the aperture diaphragm to form geometric light and diffracted light; the focal length of the lens is f, the aperture diaphragm is located at a position of 2f on the object side of the lens, and the light intensity detector is located at a position greater than 2f on the image side of the lens; the light shielding disc can be selectively located at a position of f away from the lens on the image side of the lens. The present invention also provides a detection method for the diffraction effect correction coefficient of a solar irradiance absolute radiometer, which obtains the diffraction effect correction coefficient by using experimental detection means, greatly improving the absolute measurement accuracy of the solar irradiance absolute radiometer.

To provide a technique capable of reducing the influence of the variation in the thickness of a resin cured material layer having projecting parts for developing diffraction action on the light utilization efficiency of a diffraction optical element.SOLUTION: The diffractive optical element 10 is used for at least one of division and shaping of a laser beam having a wavelength in a near-infrared region, and includes a substrate 11 that transmits the laser beam, and a cured resin layer 12 that is provided on the substrate 11 and transmits the laser beam, the cured resin layer 12 having a refractive index of 1.6 or less at a wavelength of 9400 nm, and generating a plurality of convex portions 12P that exhibit a diffractive action on a surface of the diffractive optical element 10, each of the plurality of convex portions 12P having a height H in a range of 1.4 μm or more and 1.7 μm or less, the width W is in a range of 0.4 μm or more and 1.0 μm or less.SELECTED DRAWING: Figure 1

The invention discloses a photonic crystal surface emitting laser based on electro-optical effect modulation and an emission angle and wavelength regulation and control method thereof, and belongs to the field of laser devices. The photonic crystal surface emitting laser comprises a substrate layer, an isolation layer and an active LiNbO3 layer; the isolation layer is a SiO2 isolation layer or an air isolation layer, and the air isolation layer is formed by etching the SiO2 isolation layer through a SiO2 etching agent; the active LiNbO3 layer is made of erbium-doped LiNbO3 or ytterbium-doped LiNbO3, and periodic holes are etched in the surface of the active LiNbO3 layer to form the photonic crystal layer. The photonic crystal surface emitting laser is prepared by using the active electro-optical effect material, the electro-optical effect material is combined with the photonic crystal surface emitting laser, and the emission angle and the emission wavelength are regulated and controlled through the electro-optical effect of LiNbO3 and the diffraction effect of the photonic crystal.

The present invention relates to a computed tomography spectrometer based on a metasurface diffraction element. The computed tomography spectrometer includes an optical system structure, a focal plane detector, and a data acquisition and processing system; the optical system structure includes a converging lens group, a field stop, a collimating lens group, a metasurface holographic grating, and an imaging lens group. The present invention combines a metasurface with a computed tomography spectrometer, which can avoid the manufacturing difficulties of the computed tomography spectrometer, miniaturize the computed tomography spectrometer, and produce a better diffraction effect, so that the focal plane array target surface and the overall size of the spectrometer are both in the millimeter range, and can realize an imaging spectrometer with a mobile phone terminal or even smaller structure.

The application discloses a long-wave infrared dynamic space modulation device and method based on double coding apertures, and belongs to the technical field of optics. The application avoids the diffraction effect in the long-wave infrared space modulation process by selecting a large-size coding pixel coding aperture, adopts a double coding aperture space light modulation structure, separately performs space modulation on target light beams, and realizes coding effect superposition through beam combination, so that the space modulation resolution of the large-size coding pixel coding aperture is improved. On the premise of guaranteeing the space modulation resolution requirement and without increasing the coding aperture area, the diffraction effect in the long-wave infrared space modulation process is avoided by selecting the large-size coding pixel coding aperture. The application introduces the use of a displacement table, and the position of the moving coding template is transformed for multiple times within the single information acquisition time of the system, so that the effective coding area in the optical path is transformed, more coding superposition effects are generated, and the coding resolution and the coding gray scale are further improved.

This invention claims protection for a laser device and optical path debugging method for acquiring micro-sized beams, belonging to the field of solid-state laser technology. The device structure includes: an indicator light source, a high-gain module, a micro-sized pinhole aperture, a micro-sized output mirror, and a micro-sized reflector. The debugging method consists of the following steps: S1: Determine the pitch and yaw of the micro-sized reflector using the indicator light source and the micro-sized pinhole aperture; S2: Determine the spontaneous emission light path of the high-gain module based on the micro-sized reflector and the two micro-sized pinhole apertures; S3: Add the micro-sized output mirror to achieve laser resonator oscillation based on the micro-sized cavity mirror. Because the cavity mirror is small enough, this invention eliminates the need for external pinhole beam contraction, reducing diffraction effects. Furthermore, by using an internal pinhole aperture to determine the optical path, it solves the problem of the spontaneous emission amplification optical path of the module not coinciding with the resonator oscillation optical path, improving output power and meeting the requirements for outputting micro-sized beams based on a high-gain module.

According to the laser generating device and the laser system, the image transmission device is introduced, the object image surface of the image transmission device is accurately overlapped with the two cavity reflectors of the resonant cavity, the important beneficial effects are achieved, the effective transmission distance of light waves between the two cavity reflectors is equivalently eliminated optically, and the laser generating device and the laser system have the advantages of being simple in structure and convenient to use. Therefore, the inherent diffraction effect and the mode selection capability of the resonant cavity are thoroughly inhibited; the direct result is that a large number of laser transverse modes with different orders are allowed to simultaneously meet oscillation conditions and start oscillation in a cavity, and light fields of the multiple transverse modes are combined into a large-mode-field output light beam with the spot size equivalent to the aperture of a gain medium after incoherent superposition. Moreover, the near-field energy distribution is converted from the conventional Gaussian distribution to super Gaussian distribution with a flat top and a steep edge.

The present disclosure relates to electronic devices having a display panel and a plurality of optoelectronic components, and in particular to mechanisms for mitigating diffraction effects when light is exchanged by such optoelectronic components through at least one transmissive region of the display panel. The display panel may be one of and include a layered semiconductor device that, in some non-limiting examples, may be an optoelectronic device having a plurality of (sub) pixel emission regions, each (sub) pixel emission region including a first electrode and a second electrode separated by at least one semiconductive layer.

The invention discloses an optical tomography system and method based on a long light needle metasurface lens. The system comprises a bandwidth near-infrared light source, an optical fiber circulator, an optical fiber beam splitter, a first optical fiber collimator, a plane mirror, a second optical fiber collimator, a two-dimensional scanning galvanometer, a long-light-needle metasurface lens, a collimator and a spectrograph, the bandwidth near-infrared light source emits near-infrared light, the near-infrared light is divided into two light beams by the optical fiber beam splitter after passing through the optical fiber circulator, and the two light beams are transmitted to the spectrograph. One beam of light reaches a first optical fiber collimator and then is transmitted to a plane mirror to form a reference arm signal; after the other beam of light reaches the second optical fiber collimator, the light passes through the two-dimensional scanning galvanometer and is transmitted to the long-light-needle metasurface lens, the long-light-needle metasurface lens achieves focusing through the diffraction effect of the light, high-precision three-dimensional tomography is completed, obtained sample scattering information interferes with a reference arm signal, generated interference information is returned to a collection position, and the high-precision three-dimensional tomography is achieved. And after passing through the collimator, the light enters the spectrograph to obtain corresponding interference spectrum data.

The invention provides a method for realizing ultra-high-speed translation of a Bessel beam by using double acousto-optic modulation elements, which is characterized in that the displacement in the x-axis direction and the displacement in the y-axis direction are changed at a high speed by quickly switching radio frequencies f1 and f2, so that ultra-high-speed punching on the surface of a workpiece is realized; meanwhile, each hole has excellent morphology consistency due to vertical incidence, so that the problem of hole shape distortion caused by inclined incidence at the scanning edge of a traditional galvanometer is avoided; that is to say, the all-solid-state diffractive optical element is adopted, no mechanical moving part exists, the limitation of mechanical inertia is completely eliminated, the response time of light beam displacement only depends on the change speed of a driving signal and the establishment time of the diffraction effect, the MHz-level control effect can be easily achieved, and the speed is several orders of magnitude faster than that of a traditional galvanometer. The method is especially suitable for application scenes such as laser processing, optical tweezers, confocal microscopic imaging and high-speed optical switches.

A variable light transmission device is disclosed that mitigates negative aperture diffraction effects and shows good switching speed between the open and the closed optical states. The device comprises a microcell layer disposed between two light transmissive electrode layers, the microcell layer having a plurality of microcells, each microcell including an electrophoretic medium. And each microcell comprises a protrusion structure and a channel.

The application discloses a kind of optical fiber side light extraction structure and method, belong to optical fiber side light extraction technical field, structure has including femtosecond grating light extraction component, filter component including filter layer and with slit light shielding layer, and detection component.The method includes: with grating diffraction separation optical signal in fiber core, with filter component filters optical signal, with detector receives signal.The application is by femtosecond laser in fiber core and writes small refractive index modulation area, with diffraction effect will transport light be introduced with specific angle to side, again cooperate external filter and metal slit and constitute spatial filter, physically block the stray light deviating from preset angle.This internal diffraction+external filter synergic mechanism avoids physical damage optical fiber surface, and realizes high purity, high directional signal extraction under micro size.

The utility model relates to an optical configuration capable of effectively reducing angular resolution, which comprises a first lens, a second lens, a third lens and a plane mirror which are coaxially arranged, and the lenses form a transmitting antenna of a laser range finder and are sequentially and coaxially arranged along the propagation direction of light beams output by a laser. The plane mirror is adjacent to the third lens, the two faces of the plane mirror are plated with thin films with the gradient transmittance of 1535 nm, edge stray light of laser can be eliminated, the diffraction effect is effectively reduced, the influence on the total length of an optical system is small, and the measurement precision is high. Compared with a conventional method for reducing the angular resolution by compressing the laser emission angle, the method is convenient to install and adjust, the tolerance of an optical system is large, and miniaturization and light weight of products can be achieved easily.

The invention discloses a high-angular-resolution wavefront measurement method and system based on random structure diffraction, and relates to the technical field of optical information measurement. According to the wavefront measurement method, phase modulation of incident light is realized by using a disordered diffractive optical element (DOE) in random binary phase distribution, and complex incident wavefront coding is realized through a Fresnel diffraction effect. The mapping relation between the diffraction pattern and the incident angle is further pre-calibrated through an experiment, and the wavefront to be measured is reconstructed in combination with a wavefront reconstruction algorithm. According to the scheme provided by the invention, the mapping relation between the DOE diffraction pattern and the incident angle is pre-calibrated through an experiment, accurate decoding of a local incident angle can be realized, a regional wavefront reconstruction algorithm is further combined, wavefront measurement with a large dynamic range, high spatial resolution and high angular resolution is satisfied, and the measurement precision is improved. And the method has higher reconstruction precision and real-time performance and better anti-noise capability.

An optical component has a diffraction structure for diffractively influencing a direction of emergence of light of at least one wavelength incident on the optical component. The diffraction structure includes at least two diffraction substructures superimposed in at least one portion of the optical component and having first positive diffraction structures and first negative diffraction structures. A first diffraction substructure has first positive diffraction structures and first negative diffraction structures arranged to have a symmetry following a first symmetry condition. A second diffraction substructure has second positive diffraction structures and second negative diffraction structures arranged to have a second symmetry condition differing from the first symmetry condition. This can result in an optical component for which a production of a diffraction structure with a diffraction effect for different target wavelengths and / or an improved diffraction effect for one and the same target wavelength is made more flexible.

The invention discloses an on-chip integrated high-reflection-efficiency composite grating structure, and relates to the technical field of optoelectronic devices. Through the collaborative design of the bottom film dielectric reflecting layer and the upper grating structure, the reflection efficiency is remarkably improved while the optical loss is reduced, and on-chip integration compatible with the CMOS process is realized; the film dielectric reflecting layer provides substrate reflectivity, the grating structure further regulates and controls light field distribution through the diffraction effect, and superposition enhancement of reflection efficiency is achieved through combination of the two; a metal reflecting layer is replaced by an all-dielectric material, so that plasma loss is avoided, the antenna is suitable for near-infrared to visible light bands, and the low-loss design is met; the thin film dielectric layer and the grating structure can be prepared through chemical vapor deposition (CVD), photoetching and dry etching processes, are adaptive to a silicon-based photon integration process, and have process compatibility.

A variable light transmission device is disclosed that mitigates negative aperture diffraction effects and shows good switching speed between the open and the closed optical states. The device comprises a microcell layer disposed between two light transmissive electrode layers, the microcell layer having a plurality of microcells, each microcell including an electrophoretic medium, and each microcell comprising a channel, a protrusion structure, the protrusion structure having one or more concavities.

The invention relates to the technical field of optical imaging, in particular to a multi-layer phase screen synthesis method for atmospheric turbulence simulation, which comprises the following steps of: distributing a memory in a computer, and setting an initial light field in the memory; inputting set turbulence parameters into a parameter configuration module of the computer, generating a random phase screen sequence, and loading the turbulence parameters and the phase screen sequence into a memory; the simulation initial light field sequentially passes through each layer of phase screen and then is subjected to free space propagation, and a target light field is generated; taking the target light field as an initial value of reverse propagation, performing reverse calculation through the modulation effect of each layer of phase screen and the diffraction effect of the propagation path, and synthesizing an equivalent phase diagram; performing phase extraction on the phase diagram, adding a fill factor to compensate amplitude attenuation, and mapping to a single spatial light modulator; the multi-layer phase screen synthesis method for atmosphere turbulence simulation is realized. According to the invention, propagation of light waves in a turbulent medium can be simulated more accurately, and simulation requirements of different scenes can be met flexibly.

To solve the numerous sound quality challenges encountered when using MEMS microphones utilizing microelectromechanical systems (hereinafter referred to as MEMS) based on semiconductor manufacturing technology widely used in smartphones and other devices, which are compact and possess the advantages of being durable and highly reliable due to the use of semiconductor manufacturing technology, as high-fidelity recording microphones, due to their size and structure.SOLUTION: By using a plurality of MEMS microphones in parallel, suppressing the steep peaks in the high-frequency range inherent to MEMS microphones, minimizing the effects of phase differences caused by a plurality of units, driving the frequency response compensation circuit with low power, and preventing degradation in sound quality due to diffraction effects, a microphone for high-quality audio capture is realized.SELECTED DRAWING: Figure 1

The invention relates to the technical field of optical measurement, and discloses a collimator adjustment method and system based on the diffraction effect, and the method comprises the steps: selecting and determining a point light source and a fishbone plate; mounting a fishbone plate at a light outlet of the collimator to be adjusted, and aligning the fishbone plate with an imaging system; calibrating the resolution of the area array detector, and placing the area array detector on the focal plane of the collimator to be calibrated; analyzing the diffraction pattern set, and determining an initial optimal focus position based on an analysis result; acquiring image sharpness and definition of a diffraction pattern corresponding to the initial optimal focus position, and judging whether the imaging system is out of focus or not according to the image sharpness and definition; measuring the offset of the center awn, and determining the defocusing degree according to the offset; performing secondary adjustment on the focal length according to the defocusing degree, and obtaining a final optimal focus position; and verifying the final optimal focus position of the collimator to be adjusted by adopting an auto-collimation method. According to the invention, the adjustment precision and efficiency are effectively improved.

The application is a device for testing parallelism of two gratings, which comprises a first grating, a second grating, a laser, a pinhole diaphragm, a half-transmission half-reflection prism, a pentagonal prism and an observation screen arranged on the same optical axis, and comprises two parts of adjusting grating surface parallelism and adjusting grating line parallelism. Two light spots on the observation screen are in the same horizontal straight line by adjusting the deflection angle of the first grating and the second grating through mirror reflection of the first grating and the second grating, so that the grating surface parallelism of the two gratings is adjusted. Two light spots on the observation screen are in the same vertical straight line by adjusting the rotation angle of the first grating and the second grating rotating around the horizontal direction through the diffraction effect of the first grating and the second grating, so that the grating line parallelism of the two gratings is adjusted. The application has simple structure, easy-to-understand principle and convenient operation.

The present invention relates to the field of optical measurement technology, and discloses a collimator calibration method and system based on diffraction effect. The method includes: selecting and determining a point light source and a fishbone plate; installing the fishbone plate at the light outlet of the collimator to be calibrated and aligning it with the imaging system; calibrating the resolution of the area array detector and placing the area array detector on the focal plane of the collimator to be calibrated; analyzing the diffraction pattern set and determining the initial optimal focus position based on the analysis result; collecting the image sharpness and clarity of the diffraction pattern corresponding to the initial optimal focus position, and judging whether the imaging system is defocused according to the image sharpness and clarity; measuring the offset of the central starburst and determining the defocus degree according to the offset; performing secondary adjustment on the focal length according to the defocus degree and obtaining the final optimal focus position; verifying the final optimal focus position of the collimator to be calibrated by using the autocollimation method. The present invention effectively improves the calibration accuracy and efficiency.

A variable light transmission device is disclosed that mitigates negative aperture diffraction effects and shows good switching speed between the open and the closed optical states. The device comprises a microcell layer disposed between two light transmissive electrode layers, the microcell layer having a plurality of microcells, each microcell including an electrophoretic medium, and each microcell comprising a channel, a protrusion structure, the protrusion structure comprising a conoid geometric solid.

A variable light transmission device is disclosed that mitigates negative aperture diffraction effects and shows good switching speed between the open and the closed optical states. The device comprises a microcell layer disposed between two light transmissive electrode layers, the microcell layer having a plurality of microcells, each microcell including an electrophoretic medium, each microcell comprising a protrusion structure, the protrusion structure having one or more wells.

Removing diffraction effects in a tomographic image includes: obtaining an empirical image of a sample; producing an initial wave at a radiation source; forward propagating the initial wave from the radiation source toward a detector; receiving by a sample the initial wave; forward propagating the initial wave through the sample and accumulating phase and amplitude information to produce a phase accumulated wave; back propagating the phase accumulated wave; and forward propagating the phase accumulated wave 208 while treating Fresnel diffraction, such that the empirical image is reconstructed by projections and diffraction via maximum likelihood, a Bayesian prior probability distribution, and a Fresnel propagator.

The present application belongs to the technical field of anti-fake gilding, and discloses a multilayer structure anti-fake gilding method, which comprises the following steps: step 1, manufacturing a micro-nano gilding plate with microstructure; step 2, manufacturing a transparent color-changing gilding film; step 3, printing a pattern on the surface of a substrate; and step 4, using the micro-nano gilding plate with microstructure manufactured in step 1 to stamp the transparent color-changing gilding film manufactured in step 2 on a four-color image. The gilding plate with optical microstructure is adopted in the present application to produce diffraction effects on the surface, such as light column, frosted glass, embossing and other effects. The gilding film adopts high-transparency pearl luster, and has very strong diffraction color-changing effect. The multilayer color-changing effect is achieved through the multiple superposition of light diffraction and interference to achieve the anti-fake effect. The combination and location of the printed image can meet the high aesthetic requirements, and the anti-fake pattern produced has diversity.

A holographic security code comprising: a pattern of elementary cells having a predetermined shape and a predetermined relative position, said pattern comprising a two-dimensional sequence of said elementary cells; said pattern comprising a predetermined number of so-called "empty" elementary cells, i.e. such as to appear in a predetermined dark color, in particular black, and said pattern comprising a predetermined number of elementary cells that generate a diffractive effect, so-called iridescent cells, and which each comprise at least one diffractive grating having a predetermined orientation, preferably a combination of at least two diffractive gratings that differ between their orientation; said diffractive gratings being made in such a way that the light radiation emitted is visible only with an observation according to different viewing angles comprised in a predetermined range, said pattern generating, when observed according to the aforementioned viewing angles, an image consisting of the combination of said predetermined number of so-called empty cells, having a predetermined dark colour, preferably black, and of so-called iridescent cells and in particular of different colours contrasting with said dark colour of the so-called empty cells; while with viewing angles and / or illumination outside said range of viewing angles, in particular perpendicular to the surface along which said two-dimensional sequence of elementary cells extends, said empty elementary cells and said iridescent elementary cells do not have a different appearance from each other; said elementary cells having sides lengths and / or diagonals or larger diameters in the range from 50 to 300 microns. The invention also concerns a holographic security product characterized by the fact that it comprises a substrate on which said aforementioned holographic code is applied. In addition, the invention has as its object an anti-counterfeiting verification system, said system comprising: a plurality of anti-counterfeiting labels that comprise a product of the aforementioned type; at least one code reader applied to said labels, said codes being made up of at least one said holographic code; at least one processing unit comprising a memory wherein the aforementioned codes are stored and at least one program for comparing the codes transmitted by the reader and the codes contained in said database, at least one visual and / or acoustic reception and reproduction unit associated with said reader; said processing unit generating a confirmation or denial signal of the authenticity of the code depending on the outcome of said comparison, said signal being transmitted to said visual and / or acoustic reproduction unit for the emission of visual and / or acoustic information about the confirmation or denial of authenticity of said code.