242 results about "Spherical aberration" patented technology

The application discloses a multi-marked endoscopic imaging lens for digestive tract, and belongs to the field of biomedical microscopic endoscopic imaging. The endoscopic imaging lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens; the first lens focuses laser; the second lens is matched with the first lens to limit a light beam in an effective light aperture of the lens; the third lens corrects chromatic aberration; the fourth lens and the fifth lens are combined to correct aberration; the sixth lens adopts an aspheric lens to correct spherical aberration caused in a collimating and focusing system; and the seventh lens is matched with the sixth lens to correct chromatic aberration. The working spectral range of the microscopic objective lens group is 488-860 nm, the effective light aperture is less than 1.8 mm, the mechanical outer diameter is not greater than 2.6 mm, the numerical aperture at the object side or the tissue is 0.55, the imaging field of view is 450 microns, the magnification is 2.14 times, and the working distance is 84 microns. The effect of matching excitation and fluorescence spectrum of a clinically available fluorescence contrast agent is realized.

The invention relates to a large-view-field continuous zooming optical system from visible light to a near-infrared band. The system is sequentially provided with a front fixing group with positive focal power, a zooming group with negative focal power, a compensation group with positive focal power, a rear fixing group with negative focal power and an image plane I in the light propagation direction; wherein the zoom group is composed of a meniscus lens with negative focal power and a doublet lens; and the compensation group consists of a meniscus lens with positive focal power, a meniscus lens with negative focal power and a doublet lens with positive focal power. According to the invention, two groups of doublet lenses in different forms are adopted, a negative lens in one group of doublet lenses is crown glass with low refractive index and high Abbe number, and a positive lens in one group of doublet lenses is flint glass with high refractive index and low Abbe number; and in the other group of glued lenses, the negative lens is flint glass with high refractive index and low Abbe number, the positive lens is crown glass with low refractive index and high Abbe number, and the two types of glued lenses effectively control high-order spherical aberration caused by a large view field, correct field curvature and suppress chromatic aberration caused by a wide spectral range.

The invention discloses a periscope head image difference compensation method and system, a computer and a storage medium, a periscope head comprises a reflecting prism, a lens group and a diffractive optical element, and the non-reflecting surface of the reflecting prism is provided with a polarization coating; the method comprises the following steps: constructing an optical path model according to design requirements of a periscope lens module, and carrying out aberration analysis on the optical path model; calculating a chromatic aberration compensation phase function of the diffractive optical element according to a chromatic aberration compensation formula; calculating a spherical aberration compensation phase function of the diffractive optical element according to a spherical aberration expansion formula; and calculating a total phase function of the diffractive optical element, and performing aberration compensation on the optical path model according to the total phase function. According to the long-focus periscope lens module, the total aberration of the periscope lens module can be compensated by utilizing the cooperation of the diffractive optical element and the reflecting prism with the polarization coating, so that the size of the long-focus periscope lens module is reduced, and the imaging quality of the long-focus periscope lens module is improved.

The invention relates to the technical field of microscopic optical imaging, and discloses a semiconductor conductive particle detection task-oriented differential interference optical system, which comprises an objective lens group and a differential interference module, the objective lens group comprises a front group, a middle group and a rear group which are arranged in sequence; the front group is used for ensuring a large aperture angle and less introduction of spherical aberration and chromatic aberration, the middle group is used for compensating various aberrations introduced by the front group, and the rear group is used for correcting field curvature; the differential interference module comprises a Nomarski prism, a polarizer and an analyzer which are arranged in sequence; the Nomarski prism is used for splitting and combining the linearly polarized light beams; the polarization analyzer is used for converting linearly polarized light which passes through the Nomarski prism and is orthogonal in polarization direction into linearly polarized light with the same polarization direction; the system further comprises a beam splitter and a barrel lens group. According to the invention, long working distance and large numerical aperture can be realized in the visible light wave band, the light path design is optimized so as to reduce aberration introduction, and the anti-interference capability to weak signals is enhanced.

The invention relates to a 1.2-inch intelligent traffic monitoring system lens and a working method thereof. An optical imaging system of the lens is sequentially provided with a first lens to a fourteenth lens from an object space to an image space. Wherein the focal power of each lens adopts a positive and negative combined form, so that optical aberrations such as spherical aberration and the like are greatly reduced. Wherein the fourth lens and the fifth lens form an achromatic doublet lens group, the seventh lens and the eighth lens form an achromatic doublet lens group, the ninth lens and the tenth lens form an achromatic doublet lens group, and the eleventh lens, the twelfth lens and the thirteenth lens form an achromatic triplet lens group. Through reasonable lens matching, an optical system realizes large aperture, large target surface and no defocus in day and night, and through good correction of on-axis and off-axis aberrations, the lens has good imaging quality.

The invention provides an optical system and electronic equipment. The optical system comprises a lens group, the lens group comprises a first lens group, a second lens group and a third lens group, and the first lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens; the second lens group comprises a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens; the third lens group comprises an eleventh lens, a twelfth lens, a thirteenth lens and a fourteenth lens; fG1 / f is more than-1.40 and less than-0.60; -4.50 < = F1112 / F1314 < =-1.40; fG2 / FG3 is more than 1.00 and less than 3.05; fG1 is the combined focal length of the first lens group, f is the effective focal length of the optical system, F1112 is the combined focal length of the eleventh lens and the twelfth lens, F1314 is the combined focal length of the thirteenth lens and the fourteenth lens, FG2 is the combined focal length of the second lens group, and FG3 is the combined focal length of the third lens group. The optical system effectively corrects spherical aberration, reduces the sensitivity of the optical system, and facilitates the realization of compactness and miniaturization.

The utility model discloses bionic compound eye type mine displacement monitoring special equipment, which relates to the technical field of mine safety monitoring, and comprises a shell, the shell is composed of a plurality of groups of sensing surfaces and a plurality of groups of supporting nodes, a three-ring optical system is integrated on each sensing surface, and the bottom of the shell is provided with a tenon-and-mortise quick-release interface matched with the sensing surfaces for use. The shell is in the shape of a truncated icosahedron hemisphere, the sensing face is in the shape of a regular hexagon, and the supporting nodes are in the shape of a regular pentagon. According to the utility model, the horizontal field of view is expanded to 270 degrees and the vertical field of view reaches 120 degrees through the eccentric prisms, the 4 * 4 microprism aberration correction array dynamically compensates wide-angle distortion, the microlenses employ gradient refraction design to correct spherical aberration and field curvature, light is focused into 1.2 [mu] m light spots which are matched with the photonic crystal waveguide mode field diameter, and the adjacent microlens fields of view overlap 40%. The FPGA is fused with multi-channel data, so that the signal-to-noise ratio is increased to 40dB +, accurate acquisition and processing of light are ensured, high-precision three-dimensional deformation monitoring is realized, and fine change conditions of mine rock strata can be captured.

The invention discloses an aspheric objective lens for a micro-jet laser processing head, and belongs to the field of micro-jet laser equipment, the processing head comprises a window, a water cavity and a spray head, the spray head comprises a spray hole, the aspheric objective lens, the window, the water cavity and the spray head are sequentially arranged along the optical axis direction of the aspheric objective lens, and the aspheric objective lens is used for focusing laser into the water cavity and the spray hole; the aspheric objective lens comprises a meniscus positive lens and a plano-convex aspheric positive lens which are coaxially arranged in sequence, laser is converged by the meniscus positive lens and then enters the plano-convex aspheric positive lens, and the laser is converged by the plano-convex aspheric positive lens and then penetrates through the water cavity to enter the spray hole; the surface, facing the meniscus positive lens, of the plano-convex aspheric positive lens is an even-order aspheric surface, and the surface, facing the window piece, of the plano-convex aspheric positive lens is a plane, so that the spherical aberration of the aspheric objective lens can be reduced, and the laser processing effect is improved.

The invention discloses an off-axis paraboloid mirror image difference correction high-resolution C-T type spectrum detection method and device, and belongs to the technical field of spectrum imaging and detection. The collimating mirror and the convergent mirror are off-axis parabolic mirrors. The off-axis parabolic mirror is used for correcting the spherical aberration of the spectrometer; suppressing and correcting coma of the spectrometer by using the off-axis angles of the collimating mirror and the convergent mirror and focal length symmetric structure parameters; the field curvature of the spectrograph is corrected by calculating the optimal grating position; performing linear array integral detection on the convergent light by using a small-pixel deep refrigeration array detector; by combining high and low density gratings, the gratings are switched under the application requirements of different wave band ranges, resolving power and scanning speed, and rapid light splitting detection from ultraviolet to infrared broadband is realized; high-precision grating rotary scanning and angle monitoring are utilized, and large-range spectral broadband and high-resolution detection is realized through spectral line splicing. According to the invention, wide-spectrum, high-resolution and high-sensitivity rapid detection of Raman, infrared, emission, absorption and other spectral signals can be realized.

The invention discloses a miniaturized large-target-surface low-distortion aerial photographing lens and module. The aerial photographing lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a diaphragm, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens and a fifteenth lens which are sequentially arranged from the object side to the image side along the optical axis. Through reasonable lens structure design and curvature radius control, excellent low distortion performance is realized, and the geometric accuracy of an image is ensured. The design of fifteen lenses is adopted, sufficient design freedom is provided, various aberrations such as spherical aberration are effectively corrected, high resolution is achieved, and a large-target-surface photosensitive element is matched; through focal power distribution and aberration correction, the imaging effect of an edge field of view is remarkably improved, and the definition consistency of the center and the edge of a picture is ensured.

The invention relates to the technical field of optical imaging, and discloses an automatic aberration correction system and method for remote sensing light field imaging, and the method comprises the steps: constructing an aberration sensitive feature set through dynamic projection coding and multispectral synchronous collection, and improving the aberration perception capability of a complex scene in combination with polarized light information; establishing a three-dimensional aberration field model based on a light field gradient decomposition and multi-focal length coupling model; calculating an optimal focusing parameter and a digital phase compensation mask in combination with physical driving optimization and data driving compensation; and dynamic adaptive correction is realized based on real-time aberration monitoring and light field entropy minimization optimization. According to the method, aberration such as spherical aberration, coma aberration and curvature of field can be effectively inhibited, and the resolution and depth estimation precision of remote sensing light field imaging are improved.

A first lens group comprises at least two balsaming lenses, and a first lens is used for correcting partial spherical aberration and partial field curvature of the dual-waveband confocal microscope objective; the second lens group comprises at least one balsaming lens and is used for receiving the light beams from the first lens group and correcting partial spherical aberration and partial chromatic aberration of the dual-band confocal microscope objective; the third lens group comprises at least three independent lenses, and is used for converging the light beams from the first lens group and the second lens group and correcting the residual spherical aberration of the dual-band confocal microscope objective; and the lenses in the first lens group, the second lens group and the third lens group are coaxially arranged in sequence along an optical axis. Compared with an existing product, the dual-waveband confocal microscope objective has the advantages of being dual-waveband confocal, high in resolution, long in working distance, large in view field range and the like.

The application discloses a large-view-field object-side telecentric projection imaging method and a lens for a vehicle lamp. Incident light rays are converged through two large-aperture meniscus lens; the converged light rays are reduced in size and aberration through a double cemented lens group composed of a first negative double-concave lens and a first positive double-convex lens; the light rays are further converged through a second negative meniscus lens, so that the light rays all enter a diaphragm; chromatic aberration is corrected through three cemented lenses, and aberration is further reduced, and a spherical aberration can be corrected since the aperture diaphragm is located on the object side of the three cemented lenses; the light path is further converged through two double-convex lens groups, and distortion is reduced, the light rays enter a TIR total reflection prism, pass through a protective glass, and are clearly imaged on a DMD image plane. The imaging method provided by the application can realize object-side telecentric projection imaging under a large view field through the cooperation of conditional expressions and positive and negative focal lengths between the lenses, and the imaging is high in definition.

The embodiment of the utility model provides a wide-angle lens, a shooting device and a movable platform. The wide-angle lens comprises a first lens group with negative focal power, a reflection optical element and a second lens group with positive focal power which are sequentially arranged from an object side to an image side along an optical axis, the first lens group comprises at least two negative lenses, the second lens group comprises at least five lenses, and the wide-angle lens satisfies the following conditions: 14lt; tTL / flt; 17; 90 degree lt; omega; wherein TTL is the distance on the optical axis from the object side surface of the lens closest to the object side to the imaging surface when an infinite object is focused, f is the overall focal length of the wide-angle lens, and omega is the maximum angle of the incident light of the lens closest to the object side. According to the embodiment of the utility model, the occurrence risk of ghosting and glare can be reduced, the spherical aberration can be well corrected, the lens size miniaturization can be realized while a larger field angle is ensured, and the imaging quality can be improved.

Embodiments of the present application provide an optical system for laser cutting, a laser processing device and a method. The optical system comprises, in sequence along an optical path direction, a laser, a beam processing element, a spherical aberration compensation assembly and an objective lens, wherein the laser is configured to emit a laser beam; the beam processing element is configured to process the laser beam to obtain a predetermined number of sub-beams; the spherical aberration compensation assembly comprises a predetermined number of sub-spherical aberration compensation elements, the predetermined number of sub-spherical aberration compensation elements correspond to the predetermined number of sub-beams one by one, and each sub-spherical aberration compensation element is configured to compensate the spherical aberration of the sub-beam passing through the corresponding sub-spherical aberration compensation element; and the sub-beams compensated by the sub-spherical aberration compensation elements are focused by the objective lens to form a burst point at a predetermined position of the processed object. The technical solution can obtain a better cutting effect with fewer cutting times or cutting layers, thereby effectively improving the efficiency of laser cutting.

The invention discloses an aspheric objective lens for a micro-jet laser processing head, belonging to the field of micro-jet laser equipment. The processing head comprises a window, a water cavity and a nozzle, and the nozzle comprises a nozzle. The aspheric objective lens, the window, the water cavity and the nozzle are arranged in sequence along the optical axis direction of the aspheric objective lens. The aspheric objective lens is used to focus laser light into the water cavity and the nozzle. The aspheric objective lens comprises a meniscus positive lens and a plano-convex aspheric positive lens which are arranged coaxially in sequence. After being converged by the meniscus positive lens, the laser light enters the plano-convex aspheric positive lens, and after being converged by the plano-convex aspheric positive lens, the laser light passes through the water cavity and enters the nozzle. The surface of the plano-convex aspheric positive lens facing the meniscus positive lens is an even aspheric surface, and the surface of the plano-convex aspheric positive lens facing the window is a plane, thereby reducing the spherical aberration of the aspheric objective lens and improving the processing effect of laser processing.

The embodiment of the present application provides an optical telescopic device and a multi-pupil eyepiece structure, the multi-pupil eyepiece structure comprises a first lens group with positive focal length, a second lens group with negative focal length and a third lens group with positive focal length arranged in sequence from an eye observation position to an imaging surface; the first lens group comprises a first lens for converging light; the second lens group comprises a second lens for compensating spherical aberration caused by the first lens group; the third lens group comprises a third lens with positive focal length and a fourth lens with negative focal length, the third lens is used for converging light, and the fourth lens is used for balancing residual aberration; the first lens, the second lens, the third lens and the fourth lens can meet imaging under different exit pupil conditions in multiple configurations.

The application discloses a kind of aberration correction method and device under high numerical aperture objective lens two-photon lithography, and it is related to micro-nano manufacturing and laser processing technical field.The method comprises the following steps: establishing the two-photon lithography system parameter model for aberration correction;According to the preset target focal point distribution, the focal point phase to be loaded into spatial light modulator is calculated using GS algorithm;Calculate depth-dependent aberration and generate compensation phase;Superimpose total loading phase and generate SLM hologram;Adjust objective lens to make it align with the sample on translation stage, make immersion oil and sample surface closely contact, complete the immersion alignment of objective lens and sample;Make sample and focal point produce relative displacement, complete two-photon lithography processing under the condition of spherical aberration compensation;After processing after exposure sample, obtain three-dimensional microstructure with different depth voxel.The method can improve the consistency and forming quality of deep three-dimensional micro-nano processing.

The present application relates to the technical field of optical instruments, and discloses a microscope objective, which is suitable for at least a temperature environment of 50K to 150K and comprises: a front group unit, which comprises at least a first lens and a second lens arranged in sequence along an optical path, and is suitable for converging light rays and correcting spherical aberration; a middle group unit, which is arranged on the rear side of the optical path of the front group unit, comprises at least a first middle group and a second middle group, and is arranged in sequence along the optical path, each middle group is provided with at least two lenses arranged at intervals, and is suitable for correcting chromatic aberration; and a rear group unit, which is arranged on the rear side of the optical path of the middle group unit and comprises at least two lenses arranged at intervals; each lens contained in the front group unit, the middle group unit and the rear group unit is a single lens. By arranging each lens as a single lens, the combination connection of each unit and the whole microscope objective is avoided, the problems of damage, falling or air leakage in an extreme environment such as low temperature are avoided, and the application in a low-temperature environment is met.

This invention relates to the field of AR device technology, providing an AR optical lens and an AR device. The lens includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side. The first lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; the second lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; the third lens has negative optical power, with both the object side and the image side being concave; the fourth lens has positive optical power, with a concave surface on the object side and a convex surface on the image side; and the fifth lens has negative optical power, with a concave surface on the object side and a convex surface on the image side. All lenses are aspherical lenses. This invention, through a positive-positive-negative-positive-negative optical power arrangement of lenses, can simultaneously correct various aberrations such as spherical aberration, field curvature, and distortion, effectively achieving a large field of view, low distortion, and high resolution imaging effect, enhancing the immersiveness and clarity of AR displays.

The application discloses a machining head for microjet laser processing, and relates to the technical field of microjet laser processing. The machining head comprises an objective lens, a window sheet, a water cavity and a nozzle, and the objective lens, the window sheet, the water cavity and the nozzle are coaxially arranged in sequence along a first direction. The objective lens comprises a lens barrel and first double cemented lenses, second double cemented lenses and a positive meniscus lens which are coaxially arranged in sequence in the lens barrel. The lens barrel comprises a first port and a second port, and the first direction is the direction from the first port to the second port. The spherical aberration generated by the combination of the first double cemented lenses, the second double cemented lenses, the positive meniscus lens and the window sheet satisfies a first preset range, and the chromatic aberration generated satisfies a second preset range. Thus, the chromatic aberration of blue light and green light can be corrected, and the applicability of the objective lens is improved.

The present invention relates to a method for correcting a spherochromatic aberration that occurs when examining a sample with a microscope. The microscope comprises an objective lens and a corrective device arranged in a beam path of the microscope for correcting a spherical aberration. According to the method, data for describing the spherical aberration as a function of a wavelength of light imaged by the microscope are provided. A sample is examined with the microscope, and at least one spectral range of the light imaged by the microscope is determined.A control parameter of the correction device is determined based on the provided data describing the spherical aberration as a function of wavelength for the at least one determined spectral range, in order to minimize the spherical aberration for the at least one determined spectral range. The correction device is then set to the determined control parameter. The invention further relates to a microscope, which is in particular a light microscope.

The present invention provides an intraocular lens and related technologies, which have regions concentric with a lens center O, including at least one distance region for correcting visual acuity for distance vision and at least one near region for correcting visual acuity for near vision, wherein the power in the distance region is reduced to provide a negative vertical spherical aberration that at least partially offsets the positive vertical spherical aberration caused by the cornea, and the near region has a predetermined base power at the lens center O and adds a positive fixed power to an aspherical reference power within a predetermined radial range of a virtual aspherical lens that completely offsets the positive vertical spherical aberration caused by the cornea, and the near region has at least three sub-regions arranged radially, wherein sub-region 1 provides a positive power deviation for the positive fixed power, sub-region 2 provides an approximately zero power deviation for the positive fixed power, and sub-region 3 provides a negative power deviation for the positive fixed power.

The invention discloses a gain crystal suitable for a laser, a preparation method of the gain crystal, a compensation method of thermally induced spherical aberration in a laser amplification process and the laser, and the preparation method comprises the following steps: measuring wavefront output by laser in an initial state, and obtaining a thermally induced optical path difference of the laser passing through the gain crystal under pumping; obtaining a thermotropic spherical aberration coefficient in the gain crystal through the thermotropic optical path difference; directly designing a compensation surface on the end surface of the gain crystal to obtain a geometric optical path difference of a corresponding spherical aberration generated based on the compensation surface; obtaining a geometric spherical aberration coefficient based on a compensation surface through the geometric optical path difference; the surface parameters of the compensation surface are optimized, so that the geometric spherical aberration coefficient generated by the compensation surface and the thermally induced spherical aberration coefficient in the gain crystal are equal in numerical value but opposite in sign, and then the corrected surface parameters of the compensation surface are obtained; and processing the end face of the gain crystal based on the corrected surface parameters of the compensation surface to obtain the gain crystal.

The present invention provides an optical system, a lens module and an electronic device. The optical system includes, in order from the object side to the image side along the optical axis: a first lens having positive refractive power, the object side surface of the first lens being convex, and the image side surface of the near optical axis region thereof being concave; a second lens; a third lens having positive refractive power, the object side surface of the third lens being convex; a fourth lens; a fifth lens, the object side surface and the image side surface of the near circumferential region of the fifth lens being convex; a sixth lens; a seventh lens having negative refractive power, the object side surface of the near optical axis region of the seventh lens being convex, and the image side surface of the near optical axis region being concave; and at least one of the object side surface and the image side surface of the fifth lens and the seventh lens is provided with at least one inflection point. Through the above-mentioned arrangement, the distortion, astigmatism and spherical aberration generated by the front lens group are balanced, which is conducive to improving the resolution; at the same time, the provision of multiple inflection points facilitates reducing the curvature of the lens, thereby reducing the axial thickness of the lens, which helps to reduce the size.

The application discloses a method for analyzing the existence form of As elements in pyrite based on a combination of multiple methods, which comprises the following steps: S1, selecting pyrite particles containing multiple ring zones as the object to be detected; S2, performing electron probe analysis to circumscribe the further analysis area; S3, judging the substitution property of As to Fe or S to preliminarily determine the existence form of As elements; S4, performing focused ion beam processing and spherical aberration transmission electron microscope analysis to shoot HAADF and ABF images; and S5, analyzing the spherical aberration transmission electron microscope images by using DigitalMicrograph data processing software to analyze the intensity difference of Z contrast microscopic images of different atomic sites and the abnormal atomic space occupation of heavy elements and light elements in the ABF images. The application is based on the combination of electron probe and spherical aberration transmission electron microscope, can finely analyze the existence form of As elements in pyrite from the micron to nanometer scale, and has high reliability and sufficient substantial evidence.

The invention discloses a large-view-field low-distortion infrared telecentric scanning objective lens which comprises a lens body, the lens body is composed of a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are arranged along an axis, the first lens is a positive lens, the second lens is a negative lens, the third lens is a negative lens, the fourth lens is a meniscus positive lens, and the fifth lens is a negative lens. The fifth lens is a positive lens, and the first lens and the second lens are cemented lenses. According to the invention, through combination of a plurality of lenses and the balsaming lens, high optical index, good temperature adaptability, low distortion, large target surface and large entrance pupil diameter are realized; by reasonably distributing the focal power of each lens and adopting the combination of optical materials with specific refractive index and Abbe number, various aberrations such as spherical aberration, curvature of field, chromatic aberration and the like are effectively corrected, so that high-quality imaging with system RMS wavefront less than 0.02 lambda is realized, the distortion is strictly controlled below 0.02%, and the imaging quality is greatly improved. And a sub-pixel-level accurate positioning capability is realized for high-precision machine vision and measurement detection.

The present invention discloses a miniaturized high-resolution optical system, comprising a lens comprising a first lens group with positive optical power, an effective aperture, a color filter with partial wavelength interception, a second lens group with positive optical power, and an imaging surface, arranged sequentially from the object side. The first lens group comprises a first negative lens, a second positive lens, a third positive lens, and a fourth negative lens, arranged sequentially from the object side. The first negative lens and the second positive lens form a cemented lens, or the third positive lens and the fourth negative lens form a cemented lens. The second lens group comprises a plurality of lenses arranged sequentially, wherein at least two negative lenses are provided among the plurality of lenses, and the lenses in the second lens group form at least one cemented lens group with positive optical power. Through a simple lens structure, spherical aberration, astigmatism, and chromatic aberration are well controlled, thereby achieving high resolution.

To reduce axial chromatic aberration, to secure high resolution, and to satisfactorily reduce spherical aberration and coma aberration.SOLUTION: An aperture diaphragm STO is arranged between a first lens group G1 and a second lens group G2, and the first lens group G1 is provided with a cemented lens L15 obtained by cementing a first positive lens L16 and a first negative lens J1 and having negative power. The cemented lens J1 is configured to satisfy "ndp> 1.85" (conditional formula 1), "Δ θ gF> 0.02" (conditional formula 2), "ndp> ndn" (conditional formula 3), and "ν dp <ν dn" (conditional formula 4), where ndp is an index of refraction of the first positive lens L15, ndn is an index of refraction of the first negative lens L16, Δ θ gF is anomalous dispersion, ν dp is an Abbe number of the first positive lens L15, and ν dn is an Abbe number of the first negative lens L16.SELECTED DRAWING: Figure 1

The utility model provides a laser beam converging device, which comprises a zoom lens group, a stepping motor, a moving mechanism and a controller, and is characterized in that the zoom lens group is used for converging incident laser to a working interface; the stepping motor is used for receiving a command of the controller and driving the moving mechanism to a specified position; the moving mechanism is used for loading the zoom lens group and is driven by the stepping motor to move so as to realize zooming; and the controller is used for sending a command to the stepping motor so as to control the stepping motor to move. According to the utility model, the doublet lens is adopted, the spherical aberration of the lens can be eliminated, and the light beam quality and the imaging quality of an optical system are improved; through the zoom lens group, the working distance of machining can be changed by adjusting the focal length, and the degree of production automation is improved.