124 results about "Gaussian beam" patented technology

The invention discloses a light spot adjustable optical system, a diffraction optical module and laser processing equipment, and relates to the technical field of precision processing. The optical system comprises a laser, a beam expander, a diffractive optical module and a focusing module which are sequentially arranged in the light path direction, the diffractive optical module comprises at least one diffractive optical element, and the diffractive optical element is manufactured based on a geometric phase liquid crystal polymer birefringent material. The diffractive optical module is used for regulating and controlling light spot characteristic parameters corresponding to a Gaussian beam, the Gaussian beam is emitted by the laser and enters the diffractive optical module after being expanded and collimated by the beam expander, and the light spot characteristic parameters comprise a light spot distribution position and light spot energy intensity. By the adoption of the optical system, laser energy distribution can be optimized, splashing is effectively restrained, and the welding quality and the processing efficiency are improved.

This invention presents a frequency-domain fluorescence lifetime imaging system, enhancing capabilities with a spatial beam attenuator and pinhole beam splitter. The spatial beam attenuator reshapes any beam into a circular Gaussian beam profile, being compact, cost-effective, with low loss and back reflection. Using digital printing technology, a thin optical film is deposited onto an optical substrate for precise local attenuation of the beam in either transmission or reflection mode. The pinhole beam splitter consists of an optical beam splitter with an active region the size of a pinhole, positioned near the beam's focus, which directs focused light into two paths based on acceptance or rejection by the pinhole. This configuration allows for two detectors to collect photons from both paths concurrently, facilitating dual-mode imaging. Consequently, the system can generate both confocal and conventional non-confocal laser scanning fluorescence lifetime images of the sample at the same time.

The invention belongs to the technical field of laser, and particularly discloses a beam shaping system and method based on prism pair orthogonality and cascade, and the system comprises a single-mode fiber, an aspherical lens, a first prism pair, a first parallel plate, a second prism pair and a second parallel plate which are sequentially arranged along the direction of an optical axis. A Gaussian beam emitted by a single-mode optical fiber is collimated by an aspherical lens to form a parallel beam, the beam is expanded or compressed in the X direction by a first prism pair, the beam is expanded in the Y direction by a second prism pair, and two inclined parallel plates are respectively used for compensating the beam offset in the X / Y direction; according to the invention, the circular Gaussian beam emitted by the single-mode fiber can be shaped, a large strip-shaped collimation light spot with an adjustable length-width ratio from 4: 1 to 20: 1 and a long axis size of 30mm can be realized, and the central positions of the input and output beams in the cross section are ensured to be unchanged.

This application provides a multi-parameter Gaussian beam inversion imaging method, apparatus, and device for acoustic VTI media, belonging to the field of seismic data processing technology. Based on normal time-difference correction velocity parameters, non-elliptic parameters, and Thomsen parameters, the pressure wave field control equation in the acoustic VTI medium is parameterized to obtain a migration operator. Based on the migration operator, the acquired actual seismic data is migrated to obtain actual migration imaging results. Based on the migration operator, the difference between the forward-modeled seismic data containing and without point scatterers is migrated to obtain a point spread function. The point spread function is spatially convolved with the initial perturbation parameter model to obtain simulated migration imaging results. Based on the actual and simulated migration imaging results, a first model loss is determined. The initial perturbation parameter model is iterated with the goal of minimizing the first model loss, improving the stability of imaging and parameter estimation in weakly illuminated areas.

The application discloses a three-piece Bessel beam shaping system with a diffraction ring, and belongs to the technical field of laser processing, comprising: a beam shaping mirror, a first collimating mirror and a focusing mirror; the incident surface and the exit surface of the beam shaping mirror are annular planes and annular aspheric surfaces respectively, and are used for shaping a collimated Gaussian beam into a point annular beam with energy gradually decreasing from inside to outside; the incident surface and the exit surface of the first collimating mirror are annular aspheric surfaces and annular planes respectively, and are used for collimating the point annular beam; the incident surface of the focusing mirror is a combination of an axicon surface and a spherical surface, and the exit surface is a plane; the focusing mirror is used for focusing the collimated point annular beam into a Bessel beam with a diffraction ring. The application can significantly improve the focal depth of the Bessel beam in laser processing, and can also effectively remove processing materials such as ink. In addition, the focal depth of the Bessel beam in the application is adjustable, and the adjustment mode is more, the flexibility is higher, and is suitable for different laser processing scenes.

The invention relates to the technical field of image recognition and search, and discloses a surveying and mapping device capable of automatically searching a target, which comprises a base, surveying and mapping equipment is arranged at the top of the base, a searching mechanism is arranged at the top of the surveying and mapping equipment, the searching mechanism comprises a supporting block, and the supporting block is fixedly connected to the front side of the top of the surveying and mapping equipment. A semiconductor laser is installed on the left side of the supporting block, an emission lens is fixedly connected to the right side of the supporting block, and a fixing plate is fixedly connected to the right side of the top of the surveying and mapping device. According to the invention, the transmitting lens is matched with the transmitting cylindrical mirror, an elliptical Gaussian beam emitted by the semiconductor laser is converted into a fan-shaped line light source with uniform energy distribution by adopting a means of combining slow axis collimation and fast axis beam expansion, and a specified search angle is covered; the problems of non-uniform divergence of the infrared light source in the vertical direction and low light energy utilization rate in the prior art are avoided.

The embodiment of the invention provides a beam decomposition method for electromagnetic acceleration calculation of an electrically large-sized target, and the method comprises the steps: 1, obtaining a sampling data file, and converting the related parameter information when a read antenna pattern is represented by a uniform sampling grid into a data organization form capable of carrying out query processing; 2, performing uniform sampling on a spherical surface through a gold spiral method, and determining a sub-beam center; 3, limiting a Gaussian beam edge amplitude attenuation threshold value, calculating a beam variance as a limiting condition, and controlling the shape width of the Gaussian beam to be used; and 4, completing high-fidelity beam decomposition of the directional diagram by adopting local convolution, amplitude alignment and phase cloning operation, and ensuring that each sub-beam strictly inherits original field characteristics. According to the method, distributed parallel computing of a complex scattering problem is realized through a conical beam decomposition and region mapping mechanism, and the computing efficiency is remarkably improved while the computing precision is ensured.

The invention discloses a waist-adjustable structure-integrated square elbow of a DNP-NMR (Dynamic Nuclear Polarization Nuclear Magnetic Resonance) system transmission line. The waist-adjustable structure-integrated square elbow structurally comprises two corrugated waveguide structures, a right triangle cavity, a metal ellipsoid mirror surface and two external flange structures. The square elbow is installed in a transmission line, and the corrugated waveguide receives an HE11 mode coupled by a Gaussian fundamental mode from a gyrotron, so that long-distance transmission with small loss and low cross polarization is realized in a transmission line system; the right triangle cavity is connected with the two ends of the corrugated waveguide, an HE11 mode transmitted in the corrugated waveguide is recoupled into a Gaussian base mode at the position, the transmission direction of a wave beam is changed through the metal ellipsoid mirror surface, and the space flexibility of the transmission device is improved. Meanwhile, the metal ellipsoid mirror surface also adjusts the waist radius of the Gaussian fundamental mode so as to match the input requirement of the nuclear magnetic resonance system and keep the phase consistency of the original wave beam at the same time; the external flange structure is used for being tightly connected with other straight waveguide sections, and continuity and collimation of the cavity structure are guaranteed. Compared with a split type part, the integrated square elbow has the advantages that the assembly error of a construction system is obviously reduced, the machining difficulty is low, and the standardization degree is high. And meanwhile, the device can meet the requirements of a dynamic nuclear polarization nuclear magnetic resonance system on high-efficiency, stable, flexible-direction and long-distance transmission of Gaussian beams.

The invention discloses a laser illumination and imaging lens group for a shadow imaging system, the laser illumination and imaging lens group comprises an illumination lens and an imaging lens, the illumination lens shapes a Gaussian beam into a flat-topped beam, and the flat-topped beam uniformly irradiates an object to be observed; the imaging lens images the target area to obtain a shadow contour image of the observed object. The illumination lens comprises a first lens with negative focal power and a second lens with positive focal power, and the first lens and the second lens are both aspheric lenses. The imaging lens comprises a front lens group, an aperture diaphragm and a rear lens group, the front lens group comprises a third lens, a fourth lens, a seventh lens and an eighth lens with positive focal power, and a fifth lens and a sixth lens with negative focal power, and the rear lens group comprises a ninth lens with negative focal power and a tenth lens with positive focal power. And all the lenses are spherical lenses. While the collimation and dodging effects of the laser beams are ensured, the system also has the advantages of long working distance, high resolution and the like, can meet the observation requirements of a non-luminous high-speed small-size moving object, and expands the application field of a shadow imaging system.

An apodization grating coupler based on a thin film lithium niobate platform comprises a silicon substrate, a buried silicon oxide layer, a thin film lithium niobate layer and a silicon oxide cladding which are sequentially arranged from bottom to top, and an end face coupler, a thin film lithium niobate waveguide, a light beam expander and an apodization grating are sequentially arranged in the thin film lithium niobate layer. The end face coupler couples light of the conical optical fiber into the thin film lithium niobate waveguide, and after the light is input into the apodization grating through the light beam expander, large-beam-waist Gaussian light beams are coupled through diffraction of the apodization grating. On the basis of the large-size apodization grating, through a compact plane photon structure, the 700 nm * 300 nm lithium niobate high-refractive-index single-mode waveguide can be coupled to a near-surface normal Gaussian beam with a beam waist of about 110 m and good collimation, the diffraction angle is 10 degrees, centimeter-level propagation is achieved in a free space, and the loss is 5.6 dB.

The present application belongs to the field of terahertz imaging and image processing, and particularly relates to a terahertz image data expansion method based on a space-frequency degradation model. The method mainly comprises the following steps: pre-screening and pre-processing a high-resolution image database to establish a high-resolution image library; simulating a terahertz Gaussian beam to perform fuzzy degradation processing on the high-resolution image using a Gaussian fuzzy kernel; simulating terahertz wave source fluctuation and sensor noise to add Gaussian noise; simulating low resolution of terahertz imaging, and reducing the image resolution using a bicubic downsampling method; simulating mutual interference of multiple terahertz waves during imaging, and using a scheme of adding a frequency domain mask to change the frequency domain features; simulating the case that low image contrast is caused by low terahertz wave source power, and using a gray scale compression method to compress the gray scale histogram of the image to obtain a final low-resolution image data set. The present application can effectively expand the super-resolution training set of terahertz images, thereby improving the training effect of the terahertz image super-resolution reconstruction task based on the deep learning method.

The invention relates to the technical field of forward wave oscillators, in particular to a K-band TE11 mode microwave oscillator. Comprising a cylindrical waveguide, and sequentially comprises a cut-off transition section, an interaction section and an output transition section, the cathode structure is mounted in the cut-off transition section; the anode waveguide structure comprises a plurality of slotted circular ring metamaterial units which are arranged in the interaction section at intervals in the axial direction, are linked through a metal cylinder to form a serial structure and are connected to the wall of the cylindrical waveguide to form a double-spiral anode slow wave structure; electron beams generated by the cathode structure rotate in the axial direction under the action of an external electromagnetic field, interact with each other in the anode slow wave structure to excite forward waves in a TE11 mode, and radiate outwards along an output transition section; the collector is arranged in the output transition section. On the basis of realizing a Gaussian beam TE11 mode, a traditional mode conversion structure is omitted, the structure is more compact, and light weight and miniaturization are easy to realize.

The application discloses a multi-mode vortex laser with adjustable order, comprising: a cavity lens coated with a laser wavelength anti-reflection film system, a first laser output mirror and a second laser output mirror, both of which are plane mirrors, and both of which are coated with a film system partially transmitting laser wavelength on one side and an anti-reflection film system for laser wavelength on the other side; a high-order Laguerre-Gaussian beam is focused by the cavity lens, and the focused beam waist positions of each-order Laguerre-Gaussian mode vortex light are separated under the action of spherical aberration of the cavity lens, and the higher the mode order and the larger the spot size, the closer the focused beam waist of the mode to the cavity lens; the positions of the first laser output mirror and the second laser output mirror are adjusted so as to be located at the waist positions of a certain mode, and the first laser output mirror and the second laser output mirror located at different positions provide feedback for two different-order Laguerre-Gaussian mode vortex lights, so that multi-mode vortex laser oscillation and output are formed.

The invention discloses a two-photon body imaging method and system based on a non-diffraction light needle, and the method comprises the following steps: 1, adjusting the axial focus position distribution and phase shift amount through a quasi-random spatial multiplexing algorithm according to the optical transmission characteristics, penetration depth and spatial resolution requirements of a target biological sample, and obtaining a two-photon body image; generating an optimized composite phase diagram capable of controlling the axial length and the transverse diameter of the light needle; 2, loading the phase diagram to a spatial light modulator, converting a Gaussian beam into a preset non-diffraction light needle, driving a light beam scanning module to realize single two-dimensional scanning of the light needle, and synchronously capturing a fluorescence signal to complete millisecond volume data acquisition; and 3, performing time-space mapping and information reconstruction on the time domain fluorescence signal to generate a two-dimensional projection image containing three-dimensional information. According to the invention, through effective control and rapid modulation of the light beam form, a high-speed three-dimensional imaging capability which is more friendly to a biological sample is realized, and an effective technical means is provided for researching dynamic activities of deep tissues.

This invention discloses a continuous-pulse column vector fiber laser cleaning system, comprising a laser generation module, a beam transmission and scanning module, and a motion control module. The laser generation module employs a continuous-pulse column vector laser, which integrates a control module capable of switching between continuous and pulsed output modes. It also integrates a polarization control system capable of freely switching between radial and angular polarization modes according to cleaning process requirements, and selecting to emit either a radially or angularly polarized beam. Within the reliable architecture of a time-sharing hybrid cleaning system, this laser cleaning system utilizes the unique spatial polarization and energy distribution characteristics of a column vector beam to replace the traditional fundamental mode Gaussian beam, achieving a significantly improved advanced laser cleaning system in terms of cleaning quality, process versatility, and overall efficiency.

The invention discloses a diffracted wave imaging method, a diffracted wave imaging device, diffracted wave imaging equipment and a medium based on Gaussian beam operators. The diffracted wave imaging method comprises the following steps: processing shot gather seismic records to obtain local data volumes and corresponding local plane waves in different directions; ray tracing is carried out at a seismic source position, and seismic wave real number travel time from the seismic source to an imaging point and a Gaussian beam propagation vector are calculated by using the seismic wave real number travel time; ray tracing is carried out at the beam center position, and seismic wave real number travel time from the beam center position to an imaging point and a Gaussian beam propagation vector are solved; calculating the real number travel time of the two-way seismic wave from the seismic source to the imaging point and then to the beam center position, picking up an amplitude value in the local plane wave according to the initial ray parameter of the beam center ray, and multiplying the result by the anti-stationary phase filter to serve as a migration imaging value of the imaging point; and all obtained migration imaging values are accumulated to finally obtain a diffracted wave imaging result based on a Gaussian beam operator.

The invention relates to the technical field of carbon dioxide laser tube manufacturing, in particular to a laser tube with an extended discharge tube, which comprises a gas storage tube, a water cooling tube, a discharge tube, a gas return tube, a water inlet nozzle, a water outlet nozzle and a water outlet tube, one end, close to the water outlet nozzle, of the discharge tube is prolonged, so that power is increased by 3% compared with non-prolonged power; the cathode electrode sleeves the outer wall of the extension tube wall at one end of the discharge tube; a water outlet pipe penetrating through the gas storage pipe and connected with the water inlet nozzle is of a half-circle spiral structure and half surrounds the outer wall of the water cooling pipe. The light spot mode of the laser tube is closer to a fundamental mode TEM00, and is expressed as outputting an ideal Gaussian beam with concentrated energy, circular symmetry and small divergence angle.

The wavelength specificity regulation and control device comprises a fine tuning structure and an optical fiber, the fine tuning structure is a rectangular square block, the position of the end face of the optical fiber is a half area which shields a fiber core, the thickness of the fine tuning structure meets the generated optical path difference, and a 2 pi phase difference is generated at the wavelength position of excitation light. And a pi phase difference is generated at the suppression light wavelength. According to the preparation method, one end of the optical fiber is immersed in photoresist, and development is carried out after the fine tuning structure is inscribed through the two-photon inscribing module. The wavelength specificity regulation and control device does not modulate the exciting light, keeps Gaussian beam transmission, modulates the suppression light, and modulates the shape of the suppression light into a required suppression light spot. The two light beams are simultaneously transmitted in the device, so that the problem of light beam alignment is avoided, the stability of a light path is improved, and the integration of the system is also improved by using the device.

The invention discloses a generalized vortex beam generator and a regulation and control method, and the method comprises the steps: mapping any two-dimensional curve graph to a plane-coordinate system, obtaining the original data of a curve, and carrying out the length integration of the original data of the curve, and obtaining the integral length of the curve; scaling the two-dimensional curve graph according to the set topological charge number and the curve integral length to obtain curve regulation and control data; calculating infinitesimal elements corresponding to each orientation angle according to the curve regulation and control data, performing length integration on the infinitesimal elements to obtain a phase of the vortex light beam, inputting phase distribution data into a spatial light modulator, and irradiating the spatial light modulator by using a Gaussian beam to generate the vortex light beam with a specific topological charge number; different from a traditional vortex beam design method based on a function, the phase distribution of the vortex beam is regulated and controlled according to a set curve graph, and the single axial symmetry phase distribution of the traditional vortex beam is broken through; the degree of freedom of vortex beam design is increased, and the optical information carrying capacity of vortex beams is remarkably enhanced.

The invention provides an optical device and a laser. The optical device comprises a first light splitting module, N light beam shaping modules and N second light splitting modules, n is a natural number greater than or equal to 2; the first light splitting module receives an input light beam and splits the input light beam into N Gaussian light beams in a time domain; the light beam shaping modules are arranged on the light emitting side of the first light splitting module, correspond to the Gaussian light beams one to one and convert the Gaussian light beams output by the first light splitting module into flat-topped light beams; the second light splitting modules are arranged on the light emitting side of the light beam shaping module, correspond to the flat-topped light beams in a one-to-one mode and divide the flat-topped light beams into at least two beams of output light in the spatial domain. According to the optical device and the laser, the high-energy requirement and the high-repetition-rate requirement of precision machining are met, and the productivity is greatly improved; the light beams segmented in time can be independently controlled, and the flexibility is greatly improved.

This invention discloses a device and method for real-time thermal focal length measurement of a long-pulse LDA side-pump module. The device includes a detector source, a beam expander system, an LDA side-pump module, a knife edge, an energy meter, and a signal generator. The detector source serves as the detection light source for thermal focal length measurement; the beam expander system serves as a beam expander for the detector source size; the LDA side-pump module serves as a heat source generator to achieve high peak power pump injection under long-pulse pumping; the knife edge is placed on both sides of the beam waist position after the detector source passes through the LDA side-pump module to cut the transverse and longitudinal beams, achieving beam size characterization; the energy meter is placed in the rear region of the measurement device to acquire the energy measurement of the detector source; and the signal generator serves as a timing control part to achieve timing synchronization between the detector source and the LDA side-pump module. This invention uses timing synchronization combined with Gaussian beam transmission transformation to obtain the thermal focal length value of the long-pulse LDA side-pump, which has the advantages of simple structure, ease of operation, and high measurement accuracy.

The invention discloses a terahertz time-domain spectral imaging method based on a femtosecond laser pumping-detection principle. The terahertz time-domain spectral imaging method comprises the following steps: acquiring a terahertz wave beam signal of a to-be-detected sample through a terahertz time-domain spectral system; gaussian fitting is carried out on the terahertz wave beam signal by using the terahertz wave beam model; and performing imaging reconstruction on the Gaussian fitting result of the terahertz wave beam signal by adopting a maximum likelihood and maximum expected value strategy to obtain an imaging reconstruction result. According to the terahertz time-domain spectral imaging method based on the femtosecond laser pumping-detection principle, the reconstruction technology combining the Gaussian beam model and the MLEM algorithm is introduced, the wave path calculation error is effectively reduced, the scanning imaging quality is improved, and high-resolution two-dimensional terahertz imaging is achieved; according to the method, the structural characteristics of fiber distribution, agglomeration, interruption and the like in the cigarette can be clearly presented, the defects of image blurring and multiple artifacts of a traditional back projection algorithm are overcome, and an efficient and reliable solution is provided for nondestructive testing and quality evaluation of the internal structure of a cigarette product.

This invention relates to the field of optical manipulation technology, and more specifically, to a method for optical manipulation based on a dimer. The purpose of this invention is to solve the problem of insufficient lateral optical force control. The dimer is constructed by assembling two isotropic particles, and is placed on a sample stage and completely immersed in a homogeneous medium. The optical manipulation method is as follows: a circularly polarized Gaussian beam is shaped into an incident light with an elliptical cross-section. The incident light is guided to obliquely illuminate the dimer and project an elliptical spot with a major axis and a minor axis onto the substrate of the sample stage. The angle of inclination formed by the incident light and the normal to the substrate of the sample stage is ∈ (0°, 90°), with the major axis perpendicular to the propagation direction of the incident light and the axis of the dimer parallel to the minor axis, so that the incident light induces a lateral optical force on the dimer, the direction of which is parallel to the major axis. By adjusting the rotation direction of the circularly polarized Gaussian beam and the angle of inclination, optical manipulation of the dimer's motion direction and velocity can be achieved.

The invention discloses a femtosecond laser operation flat-topped beam shaping optical system which comprises a laser, a beam expander, a DOE shaping module and a focusing scanning module. The laser is used for outputting a femtosecond Gaussian laser beam, and the femtosecond Gaussian laser beam sequentially passes through the beam expander, the DOE shaping module and the focusing scanning module and then acts on an operation area; the beam expander is used for expanding the diameter of the femtosecond Gaussian laser beam to the beam diameter used for cutting the light path; the DOE shaping module comprises a DOE diffractive optical element; the DOE diffractive optical element is arranged on a path of the femtosecond Gaussian laser beam and is used for converting an incident Gaussian beam into a flat-topped beam with uniformly distributed energy through phase modulation; the flat-topped light beam has no local energy peak value, thermal damage and excessive ionization of traditional Gaussian laser to normal tissues of eyes are avoided, postoperative inflammatory response is light, the tissue recovery speed is increased, and the risk of operative complications is reduced.

The utility model relates to the technical field of laser measurement, and discloses Gaussian beam measuring equipment, which comprises a helium-neon laser transmitter, a camera, a guide platform, a mobile platform and a lens, the helium-neon laser transmitter is erected at one end of the guide platform; the camera is arranged on the moving platform, and the moving platform is arranged on the guide platform in a sliding mode in the length direction of the guide platform; and the lens is positioned on a connecting line between the helium-neon laser transmitter and the camera. A plurality of parts are combined, the helium-neon laser transmitter and the camera are arranged in an adjustable mode, the camera is movably arranged on the guide platform through the movable platform, fast assembly and adjustment are facilitated, compared with traditional integrated equipment, different devices can be replaced and maintained independently, and the cost is reduced. Different requirements in different teaching experiments can be met by replacing part of devices in the equipment, the expansibility is high, and the overall use efficiency and reliability of the equipment are improved.

The invention provides a refractive index non-contact measurement method based on Gaussian beam local sampling, and relates to the technical field of laser measurement, and the method comprises the following steps: setting an iris diaphragm on a propagation path of a Gaussian beam, and moving the iris diaphragm along the direction of an optical axis to obtain corresponding first transmission light power at different axial positions; calculating first beam waist positions of the Gaussian beam based on the first transmission light power at multiple different axial positions and a beam waist position fitting function, and integrating multiple groups of first beam waist positions to obtain a calibrated beam waist position; measuring the offset of a second beam waist position relative to the calibration beam waist position after the Gaussian beam is transmitted by the transparent medium to be measured; and according to the offset and the thickness of the transparent medium to be measured, constructing a refractive index fitting function to invert the refractive index corresponding to the transparent medium to be measured. According to the invention, the measurement efficiency and the measurement stability can be improved.

This invention relates to the field of antennas, and one example of the invention relates to an antenna structure (10) for guiding the directional radiation of light. The antenna structure (10) includes a reflector (12) having a reflective surface (12a), an annular dielectric grating (14) arranged on the reflective surface (12a) and extending concentrically along a central axis (100) perpendicular to the reflective surface, and an omnidirectional reflector formed by a low-refractive-index central region (18) surrounded by the annular dielectric grating (14). The antenna structure (10) allows light emitted from the low-refractive-index central region (18) along the central axis (100) onto the dielectric grating (14) to achieve a projection efficiency η relative to a Gaussian beam of at least 65%. Other examples of the invention also relate to a light-emitting device (22) and a method for designing the antenna structure (10).

The application discloses a diffraction field calculation method, device and equipment of a Bessel Gaussian beam and a medium, the Bessel Gaussian beam is reflected by a conical surface of an off-axis conical mirror, and a Gaussian beam is reflected at a preset incidence angle; the method comprises the following steps: obtaining a first light field distribution of a reflected beam formed after the Gaussian beam is just reflected on the off-axis conical mirror; based on the first light field distribution, a virtual surface is constructed, and a third light field distribution of the Gaussian beam on the virtual surface is obtained; the discretization spectrum of the third light field distribution is determined; the discrete sampling point coordinate set of the Bessel Gaussian beam on a preset diffraction field is determined; based on the discretization spectrum, the discrete sampling point coordinate set is subjected to non-uniform discrete Fourier transform, and the second light field distribution of the Bessel Gaussian beam on the preset diffraction field is obtained. The application provides a low-complexity and fast calculation algorithm for calculating the diffraction field of the Bessel Gaussian beam generated by the off-axis conical mirror.

This invention relates to the field of laser processing inspection technology, and discloses an online optical device and method for monitoring laser output power. The monitoring optical device includes a laser power detector, a forward shaping device, and a perforated mirror. The forward shaping device shapes a large-diameter Gaussian beam into a beam centered on a small-diameter Gaussian beam with an outer ring of light. A detection aperture is formed at the center of the perforated mirror along the axial direction of the forward shaping device. The small-diameter Gaussian beam passes through the detection aperture to the laser power detector, and the outer ring light is reflected by the perforated mirror into the processing optical path. This application also discloses a monitoring method based on the above-mentioned monitoring optical device. The monitoring optical device and method of this application fundamentally eliminate the influence of changes in the polarization state and incident angle of the light source on the transmitted output laser power, maintain stable laser output power monitoring, have high detection accuracy, and improve the reliability of the online monitoring system.

This utility model discloses a high-order Hermit-Gaussian laser generator, comprising a pump source for providing laser light, and a first lens, a laser gain medium, a second lens, and an output coupling mirror arranged coaxially along the laser direction emitted from the pump source. The laser gain medium and the output coupling mirror are spaced apart and form a laser resonant cavity. The second lens is movably disposed within the laser resonant cavity and is positioned close to the laser gain medium along the laser direction emitted from the pump source to form a fundamental mode Gaussian beam. By performing an off-axis translation of the second lens in a plane perpendicular to the laser direction emitted from the pump source, the fundamental mode Gaussian beam is converted into a high-order Hermit-Gaussian laser beam, which is then output through the output coupling mirror. This method can replace the off-axis pumping method used in the prior art to generate a high-order Hermit-Gaussian laser beam to obtain a vortex laser.