52results about How to "Improve focus quality" patented technology

An improved thermionic cathode is provided. The cathode has a carbon-coated cone surface and reduced cone angle (e.g. typically 60 degrees or less) that delivers an electron beam with high angular intensity and brightness and exhibits increased longevity.

The invention discloses a high-speed and high-resolution scanning microscopic imaging system and method based on machine learning. The phase distribution is obtained by combination of Zernike polynomial coefficients and loaded into a spatial light modulator to obtain distortion focus spots; the light intensity distribution of all the distortion focus spots and the corresponding Zernike polynomialcoefficients are input into machine learning network, and training is performed to obtain a correction model; the light intensity distribution of the distortion focus spots is input into the correction model, and calculation is performed to obtain various Zernike polynomial coefficients and obtain the corrected phase distribution; the corrected phase is loaded on the spatial light modulator to achieve aberration correction so as to reconstruct a high-quality focus spot. The correction speed of optical aberration is improved, fast aberration correction in the process of optical microscopic imaging is achieved, a new idea is provided for high resolution imaging and high precision detection deep inside a living biological tissue, and a good application prospect is achieved in the field of biomedical research.

The invention discloses an ISAR motion compensation method based on a design structuration Gram matrix, which belongs to the technical field of radar imaging. Motion compensation is an important step in an ISAR imaging algorithm. According to the invention, motion compensation is attributed to a multi parameter estimation problem. An optimization theory based on the design structuration Gram matrix provides a new motion compensation method. The method can be divided into two parts of range alignment and phase compensation. According to a range alignment algorithm, the correlations between all range profiles approach the maximum at the same time to realize offset estimation. According to a phase compensation algorithm, by analyzing a signal model, an optimal matrix is derived, and an optimization method is used to extract a phase error. According to the invention, the correlations between echo pulses are fully used; high precision estimation is carried out on the range offset and the phase error; the algorithms have high robustness, and are suitable for the condition of echo random sampling; and a compression sensing technology has a practical application prospect in the field of ISAR imaging.

The present invention relates to a beam optical component (1, 201) for acting on a charged particle beam (63) including a first element (3; 203) having a first opening (9; 209) for acting on the charged particle beam (63), at least a second element (5; 205) for acting on the charged particle beam (63); at least one distance piece (20a, 20b, 20c) positioned between the first element (3; 203) and the second element (5; 205) to define a minimum distance between the first element (3; 203) and the second element (5; 205); and a first holding piece (30a; 30b; 30c) for abutting the first element (3) to the at least one distance piece (20a, 20b, 20c), whereby the first holding piece (30a; 30b; 30c) is attached to the at least one distance piece (20a, 20b, 20c). First and second elements (3; 203; 5; 205) are preferably electrodes or pole pieces to act on the charged particle beam by an electrostatic or magnetic force. With the first holding piece (30a; 30b; 30c) attached to the at least one distance piece, distorting mechanical forces on the first and second elements (3, 5) are reduced which improves the performance of the respective beam optical components (1; 201).

The invention provides a method of compensating motion error of a multi-aperture synthetic aperture sonar. The method carries out average processing on independent echo data measurement at each time, common motion error information is extracted, and sway error of the multi-aperture synthetic aperture sonar can further be estimated. The method of the invention can estimate the sway error of the multi-aperture synthetic aperture sonar with a small amount of calculation, and thus, the focusing quality of the multi-aperture synthetic aperture sonar image is further improved.

The embodiment of the invention belongs to the technical field of laser fragmentation, and relates to a laser fragmentation method for a solid material. The technical scheme provided by the invention is that the method comprises the following steps: forming a stripping surface in a solid material by using laser; bonding a solid material to the surface of the solid substrate through thermoplastic glue; and separating the solid material along the stripping surface to obtain a thin-layer wafer with a predetermined thickness. The laser is utilized to form the stripping surface in the solid material to be separated, the consistency of the thickness of the thin-layer wafer is ensured, the thermoplastic glue and the solid substrate are adopted to assist in stripping, the stripping process is simple and reliable, the thin-layer wafer obtained after stripping is easily separated from the solid substrate, the production cost is reduced, and the production efficiency is improved.

The invention discloses a digital-micro-mirror-device-based fast precise optical focusing enhancement method and system. Region division is carried out on a digital micro mirror device and the digital micro mirror device is divided into two parts evenly; divided areas in the second part are kept to be unchanged and intensity modulation is carried out simultaneously on light beams at all divided areas in the first part at different frequencies, fluorescent light with changed intensities is excited after light beam focusing, and the excited fluorescent light is received and recorded by a photomultiplier; after Fourier transform on a fluorescent light signal, compensation phases corresponding to all divided areas are obtained; the divided areas in the first part are kept to be unchanged d intensity modulation is carried out simultaneously on light beams at all divided areas in the second part to obtain another halves of compensation phases; the divided areas with the phase values smaller than pai are kept and the divided areas with the phase values larger than pai are removed to obtain screened divided areas; and after the digital micro mirror device loads the screened divided areas, the light beams are focused in a sample to form a light spot with the higher central light intensity. On the basis of the optical diffraction principle, the beam focusing speed is increased and the light beam focusing capability is enhanced. A feasible focused light spot generation method can be provided for the non-fiber interpolation type optogenetics and the deep penetration microimaging.

Ultrasonic radiation generating device for ultrasonic therapy. Ultrasonic senders (S1-S3) that produce ultrasonic beams (U1-U3) having differing foci (F1-F3). Each ultrasonic sender is assigned an ultrasonic source (Q1-Q3) for focusing the ultrasonic beams (U1-U3). A close lens (L1-L3) is arranged on the emission surface of each ultrasonic source.

The invention discloses an ultrashort pulse laser scanning device. It includes acoustooptic modulator and 2-D acousto-optic deflector which are at the same light path, the 2-D acousto-optic deflector is constructed with two acousto-optic deflectors, the included angle between the acousto-optic deflector and the acoustooptic modulator is 45+-5 degree. The modulating frequency of the acoustooptic modulator is fAOM=f+-10%f, the distance between the acoustooptic modulator and 2-D acousto-optic deflector is D=L+-10%L. When acousto-optic deflector is used to 2-D scan the laser, the device can compensate the spatial dispersion and temporal dispersion introduced by using acousto-optic deflector to scan ultrashort pulse laser beam. The device possesses simple structure, light path is easy to adjust, and it fits for the fields of femtosecond laser storage, imaging and laser micro-processing, specially the random scan of the laser beam.

The invention provides a laser beam focusing integer type parabolic mirror, comprising mirror surface, each point on the surface satisfies the curved surface equation, wherein, (x,y,z) is one point on the rectangular axis, f is focus of the parabolic mirror, h is the distance between the center of the mirror surface and y axis, satisfying formular, or f<h<3f, D is clear aperture of the parabolic mirror. The parabolic mirror can focus the original laser beam to be strip type light spot of certain size with even light distribution, widely used for laser cutting, laser surface heat treating, laser quenching and the like field for processing material using high energy laser beam. The invention also provides a method for producing the laser beam focusing integer type parabolic mirror formed in one piece using a rotary type high accuracy machine tool, with features of simple technique, increased capacity of reflector for proofing the high power laser beam and heat-sinking capability, and improved focusing quality of laser beam.

The invention provides a circular track SAR reconstruction method based on mark point phase gradient extraction. The method comprises the following steps: a plurality of mark points are selected from a scene, and ground horizontal plane coordinate system coordinates of a circular track SAR aerial carrier and the various mark points are obtained; according to the ground horizontal plane coordinate system coordinates of the circular track SAR aerial carrier and the various mark points, a phase gradient of each mark point is extracted from target echo signals received by the a circular track SAR, and real slope distance variances from the mark points to a real track is calculated according to the phase gradients; and through the utilization of the ground horizontal plane coordinate system coordinates of the circular track SAR aerial carrier and the various mark points and the slope distance variances of the mark points, a circular track SAR track is reconstructed. The above method solves a problem that present circular track SARs depend on high precision navigation measurement. The method not only can be used for the high precision track reconstruction of the circular track synthetic aperture radar, but also is applicable high precision track reconstruction of SARs of any track.

The invention discloses an SAR real time self-focusing method based on phase error direct estimate, belonging to the radar imaging technology field. The method comprises the steps as follows: selecting strongest scattering point of each distance unit below the PGA algorithm processing structure, removing the strongest scattering point of each distance unit to the centre of the distance unit, adding window for the image of each distance unit, obtaining the fixed phase difference value between the remaining distance unit and the reference distance unit, eliminating the fixed phase difference value from each distance unit, having weighted average on the distance unit signal after eliminating the fixed phase difference value to obtain the phase error function, and compensating the phase error function. The phase error function is directly estimated after executing the unbiased estimation on the fixed phase difference for reducing the iterative times, reducing operation number, obviously improving focusing quality, the method is applied to the SAR image with long-scale contrast and without stronger target.

The invention relates to a desulfurization process of high-sulfur petroleum coke. The desulfurization process comprises the following steps: uniformly mixing alkali liquor and high-sulfur petroleum coke to be desulfurized to obtain a mixture; loading the mixture into an autoclave, activating for 2-8 hours at a temperature of 40-100 DEG C under a pressure of 20-60 MPa, drying for 8-10 hours at a temperature of 100-120 DEG C to obtain an activated material; uniformly mixing the activated material, a catalyst and an oxidant, carrying out oxidation for 5-15 hours at a temperature of 60-150 DEG C to obtain slurry; carrying out suction filtration on the slurry to obtain a solid-phase substance, drying the solid-phase substance at a temperature of 100-120 DEG C for 8-12 hours, and calcining the solid-phase substance to obtain low-sulfur petroleum coke. The desulfurization process is high in desulfurization rate, and the obtained low-sulfur petroleum coke is good in quality.

The invention discloses a laser acoustic underwater communication system adaptive to wave height, and relates to the field of laser acoustic underwater communication, for solving the problem that in the prior art, the wave height cannot be adaptively adjusted, and the photoacoustic conversion efficiency is low and the underwater communication quality is poor under the condition that the weather isbad and the carrying platform is large in disturbance. The system comprises a laser, a beam expander lens set, an optical focusing system, a laser ranging system, a controller and a motor; light beams emitted by the laser is subjected to beam expanding of the beam expander lens set, then enters the optical focusing system, and is focused underwater after passing through the optical focusing system, so as to motivate to generate sound waves for communication, and to motivate the laser ranging system to measure the wave height in real time, sea level altitude data measured in real time is transmitted to the an overall control system, after data processing, an electrical signal is transmitted to the motor, and the motor controls the optical focusing system to adjust correspondingly to compensate the sea level altitude change caused by waves, so that the best underwater laser focusing position is kept, and the breakdown position of the underwater communication system is adjusted in real time.

A method for identifying an abnormal disc includes the steps of: forming three testing spherical aberration (SA) values including an SA value of a thinner data layer, a standard SA value and an SA value of a thicker data layer; adjusting to one of the testing SA values; performing focus for a target disc and recording a focus error signal; obtaining a maximum focus error signal and a corresponding testing SA value by way of comparison; and checking whether the corresponding testing SA value is equal to the standard SA value, and identifying the target disc as a normal disc if yes, or otherwise identifying the target disc as the abnormal disc and re-adjusting the SA value to enhance the signal quality.

The invention relates to the field of digital photo- and video-recording, and may be used for recording and monitoring distant objects, such as expanses of forest. The technical result is directed at enhancing the focus quality of the images produced. A method for producing a photo- or video-image of at least one object to be recorded, consisting in: producing an image of an object to be recorded by means of an electronic optical device; wherein, a focusing object, corresponding to at least one object to be recorded and satisfying the following conditions, is first selected for the object to be recorded: the focusing object has higher contrast than the object to be recorded, and the object to be recorded is located within the bounds of the depth of field. Then, an image is produced of the at least one object to be recorded, in which the electronic optical device is focused on the focusing object corresponding to the object to be recorded, the focusing parameters are set, and said focusing parameters are used for producing an image of the object to be recorded.

The invention provides a non-invasive skin treatment device (200) comprising: a light source (10) constructed for emitting treatment light (15), an optical system (20) constructed for focusing the treatment light along an optical axis (OA) to a focus position (320) inside the skin tissue (300), and an indenter (30) comprising a skin contact surface (34) having an aperture (A1) at a distance from the optical system for allowing the treatment light to be focused through the aperture into the skin tissue. The indenter is configured and constructed for generating, in a cross-section of the aperture taken along the optical axis and along a cross-section direction wherein the aperture has a width dimension, a maximally curved protrusion of skin tissue freely protruding through the aperture towards the optical system by pressing the indenter against the skin surface of a specific skin type with a pressure exceeding a predefined pressure, a skin surface of said maximally curved protrusion having a radius of curvature (RC) at an intersection with the optical axis. The optical system is configured and constructed for generating a focused beam of the treatment light having, in said cross-section of the aperture at said intersection, a wave front with a radius of curvature ranging between 75% and 125% of said radius of curvature (RC) of the skin surface of said maximally curved protrusion.

The invention discloses a photothermal effect measurement system and method of a strong scattering material and relates to the technical field of non-destructive testing of materials. The system comprises a computer, a function signal generator, a laser, a testing platform for storing a to-be-tested material, a condensation module, a signal feedback module electrically connected with the computer,a light path converter and an SLM (spatial light modulator), wherein the light path converter and the laser are arranged at the same horizontal height, the SLM is electrically connected with the computer, the testing platform is arranged right below the light path converter, the condensation module is used for gathering modulated laser, a sample has temperature rise and fall and infrared radiation under the photothermal effect after the laser irradiates the sample, and radiation signals produced by the to-be-tested material are collected and reflected to the signal feedback module. The SLM isused for performing wavefront regulation and compensating the scattering phase, so that the absorption effect is improved, strong scattering in material characteristic measurement is reduced, and infrared radiation signals on the surface of the material are enhanced.