Laser illumination and imaging lens group for shadow imaging system

Abstract

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.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, and more specifically to a laser illumination and imaging lens assembly for a shadow imaging system. Background Technology

[0002] Photolithography machines are the core equipment in the field of photolithography technology. Currently, the most advanced extreme ultraviolet (EUV) lithography machines use 13.5nm extreme ultraviolet light. The mainstream solution for generating EUV light is laser plasma (LPP). LPP light sources utilize the interaction between high-energy pulsed lasers and the target material to form a high-temperature, dense plasma, which then radiates EUV light. Liquid tin targets are currently the mainstream target material. Liquid tin targets used to effectively generate EUV light typically have the characteristics of high frequency, high speed, large spacing, and small diameter, and need to have sufficiently high stability. Since the liquid droplets themselves do not emit light, in order to accurately control the size of the liquid tin droplets and the spatiotemporal stability of the falling process, a shadow imaging system is needed to record the state and changes of the falling droplets in real time.

[0003] A shadow imaging system mainly consists of a light source, an illumination lens, an imaging lens, and a camera. The light emitted by the light source is homogenized by the illumination lens and then illuminates the droplet to provide the background light required for imaging. The imaging lens and camera are used to acquire droplet images. In LPP (Low Pulse Peel) light sources, the droplets fall at speeds of tens of meters per second. The droplet motion causes motion blur in the acquired droplet images. Therefore, the light source in a shadow imaging system needs to use a stroboscopic light source so that the camera only captures the droplet image during the light source's emission time, thus reducing the camera's exposure time. The size of tin droplets in LPP light sources is typically tens of micrometers, which requires the shadow imaging system to have high spatial resolution. Currently, shadow imaging systems mainly use LEDs as stroboscopic light sources. However, LEDs have disadvantages such as low luminous intensity and long pulse duration. Furthermore, existing imaging lenses have relatively low resolution, resulting in poor image quality when observing high-speed, small-sized droplets.

[0004] Compared to LED light sources, laser light sources offer significant advantages such as shorter pulse widths, higher energy, and better monochromaticity. Laser pulse widths can easily reach nanosecond levels, and their output light intensity is far higher than that of LEDs. This effectively solves the problem of motion blur caused by high-speed droplets. Furthermore, the superior monochromaticity of lasers means that chromatic aberration does not need to be a major concern in lens design, greatly reducing the complexity of lens design. Lasers also have significant advantages as stroboscopic sources in shadow imaging systems. Typically, the output beam intensity of a laser light source exhibits a Gaussian distribution, and its coherence is stronger than that of LED light sources. Illumination and imaging lenses designed based on LED light sources cannot meet the requirements of laser light sources. Illumination and imaging lenses based on laser light sources need to be redesigned and optimized to take into account the characteristics of lasers.

[0005] Therefore, exploring more suitable illumination and imaging lens architectures for laser light sources, as well as the design of illumination lenses that ensure uniformity of laser light source illumination and imaging lenses with high spatial resolution, is of great significance. This can not only improve the ability of shadow imaging systems to observe droplets in LPP light sources and accelerate the development of EUV lithography machines, but also expand the application of shadow imaging systems in more fields. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides an illumination and imaging lens based on a laser light source, which is applied to a shadow imaging system. The laser is used as the strobe light source in the shadow imaging system, which solves the problems of motion blur and low spatial resolution when observing high-speed, small-sized moving objects in shadow imaging systems based on LED light sources.

[0007] The technical solution of the present invention is as follows: A laser illumination and imaging lens assembly for a shadow imaging system is characterized by comprising an illumination lens and an imaging lens arranged coaxially. The illumination lens is located on the laser source side and is used to shape the Gaussian beam output by the monochromatic laser into a collimated flat-top beam and illuminate the object to be measured behind it. The imaging lens is located on the image side and is used to receive and converge the beam from the object to be measured so as to form a high-resolution shadow image of the object to be measured on the image plane. The illumination lens C1 includes, along the optical path, a first lens L1 with negative optical power and a second lens L2 with positive optical power, and the surface parameters of the first aspherical lens and the second aspherical lens satisfy the energy redistribution mapping relationship from Gaussian beam to flat-top beam. The imaging lens, along the optical path from the object side to the image side, includes a front lens group aperture stop with positive optical power and a rear lens group with negative optical power. The front lens group, mainly used to converge light rays and correct aberrations, consists of six spherical lenses: a third lens with positive optical power, a first cemented lens formed by cementing a fourth lens with positive optical power and a fifth lens with negative optical power, a second cemented lens formed by cementing a sixth lens with negative optical power and a seventh lens with positive optical power, and an eighth lens with positive optical power. The rear lens group is used to adjust the principal ray angle to improve the uniformity of image illumination and, together with the front lens group, achieves micron-level optical resolution at working distances greater than 100 mm. It consists of a third cemented doublet lens formed by cementing two spherical lenses: a ninth lens with negative optical power and a tenth lens with positive optical power.

[0008] Furthermore, all lenses in the illumination lens are aspherical lenses. The first lens is a plano-concave lens with negative optical power, where the side facing the laser source is flat and the side facing the object surface is concave. The focal length of the first lens...f 1<0; The second lens is a plano-convex lens with positive optical power. The side facing the laser source is convex, and the side facing the object surface is flat. The focal length of the second lens is... f 2 0.

[0009] Furthermore, the optical power of the front lens group φ 1 0, the optical power of the rear lens group φ 2 < 0.

[0010] Furthermore, the imaging lens satisfies the following relationship: The third lens has a concave surface on one object plane and a convex surface on the other, with a diameter of 110mm. f 3<205mm, 1.71< Nd 3 < 1.80, 45 < Vd 3 < 60; The fourth lens has a concave object plane and a convex image plane, 141mm < f 4<200mm, 1.45< Nd 4 < 1.56, 65 < Vd 4<75; The fifth lens has a concave object plane and a convex image plane, with a diameter of -171mm. f 5 < -127mm, 1.76 < Nd 5 < 1.90, 20 < Vd 5 < 30; The sixth lens has a convex surface on one object plane and a concave surface on the other, with a diameter of -336mm. f 6 < -155mm, 1.72 < Nd 6 < 1.85, 36 < Vd 6<45; The seventh lens has a convex surface on both the object plane and image plane sides, with a diameter of 152mm. f 7<251mm, 1.45< Nd 7 < 1.56, 65 < Vd 7<75; The eighth lens has a convex surface on one object plane and a concave surface on the other, with a diameter of 149mm. f 8<234mm, 1.75< Nd 8 < 1.80, 45 < Vd 8<55; The object plane side of the ninth lens is concave, and the image plane side is concave, -45mm< f 9 < -15mm, 1.48 < Nd 9 < 1.60, 55 < Vd9<65; The tenth lens has a convex surface on both the object plane and image plane sides, with a diameter of 30mm. f 10 <60mm, 1.59< Nd 10 <1.65, 55< Vd 10 <65; in, f 3 represents the focal length of the third lens. Nd 3 represents the refractive index of the third lens. Vd 3 is the Abbe number of the third lens. f 4 represents the focal length of the fourth lens. Nd 4 represents the refractive index of the fourth lens. Vd 4 is the Abbe number of the fourth lens. f 5 represents the focal length of the fifth lens. Nd 5 represents the refractive index of the fifth lens. Vd 5 is the Abbe number of the fifth lens. f 6 represents the focal length of the sixth lens. Nd 6 represents the refractive index of the sixth lens. Vd 6 is the Abbe number of the sixth lens. f 7 represents the focal length of the seventh lens. Nd 7 represents the refractive index of the seventh lens. Vd 7 is the Abbe number of the seventh lens. f 8 represents the focal length of the eighth lens. Nd 8 represents the refractive index of the eighth lens. Vd 8 is the Abbe number of the eighth lens. f 9 represents the focal length of the ninth lens. Nd 9 represents the refractive index of the ninth lens. Vd 9 is the Abbe number of the ninth lens. f 10 The focal length of the tenth lens is... Nd 10 The refractive index of the tenth lens is... Vd 10 Let be the Abbe number of the tenth lens.

[0011] Furthermore, both the illumination lens and the imaging lens operate at monochromatic wavelengths; The working distance of the illumination lens WD 1≥10mm, illumination range Φ 1≤6mm; The working distance of the imaging lens WD 2≤110mm, optical resolution of the object δ≥1µm, imaging field of view Φ 2≤4.76mm.

[0012] The beneficial effects of this invention are as follows: This invention optimizes the design of an illumination lens and an imaging lens based on a laser light source. The lens assembly is designed specifically for the characteristics of laser light. The illumination lens can shape a Gaussian beam into a flat-top beam, providing excellent beam homogenization and collimation. Compared to LED light sources, stroboscopic laser illumination has a shorter pulse width and higher energy, solving the problem of motion blur in high-speed moving objects. The imaging lens maintains high spatial resolution even at long working distances, enabling clear imaging of small objects and addressing the low resolution issue of existing shadow imaging systems. This improves the observation capabilities of shadow imaging systems and expands their application scenarios. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the optical structure of a set of illumination and imaging lenses based on a laser light source according to the present invention; Figure 2 This is a schematic diagram illustrating the principle of Gaussian beam shaping for the illumination lens of this invention. Figure 3 This is the optical path diagram of the lens assembly in Embodiment 1 of the present invention; Figure 4 This is a light energy distribution diagram of the illumination lens in Embodiment 1 of the present invention; Figure 5 This is a wavefront aberration diagram of the illumination lens in Embodiment 1 of the present invention; Figure 6 This is a dot diagram of the imaging lens in Embodiment 1 of the present invention; Figure 7 This is an MTF curve of the imaging lens in Embodiment 1 of the present invention; Figure 8 This is the optical path diagram of the lens assembly in Embodiment 2 of the present invention; Figure 9 This is a light energy distribution diagram of the illumination lens in Embodiment 2 of the present invention; Figure 10 This is a wavefront aberration diagram of the illumination lens in Embodiment 2 of the present invention; Figure 11 This is a dot diagram of the imaging lens in Embodiment 2 of the present invention; Figure 12 This is the MTF curve of the imaging lens in Embodiment 2 of the present invention. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0015] Objects observed by shadow imaging systems typically do not emit their own light, requiring an additional illumination source for imaging. Some objects have high light absorption or low light reflectivity; when illumination light is incident on the surface of these objects, most of the light energy is absorbed or transmitted, making imaging methods using reflected or scattered light unsuitable. For these objects, backlighting is necessary, illuminating them with uniform background light. The light intensity in the object's area is reduced due to the obstruction of light, allowing imaging of the target area to obtain the object's outline. Laser sources have characteristics such as short pulse width, high energy, and good monochromaticity. Compared to LED sources, laser sources are more suitable for imaging high-speed moving objects. However, the intensity distribution of a laser beam differs significantly from that of an LED beam. Therefore, illumination and imaging lenses based on laser sources need to be redesigned and optimized to take into account the characteristics of lasers.

[0016] This invention provides a set of illumination and imaging lenses based on laser light sources, such as... Figure 1 As shown, the plane where the laser source LASER is located is the laser incident plane, the plane where the object OBJ is located is the object plane, and the plane where the image IMA is located is the image plane. The lens group includes an illumination lens C1 and an imaging lens C2, which are placed coaxially. The object to be observed is located between the illumination lens C1 and the imaging lens C2, i.e., at the object plane position.

[0017] The illumination lens C1 shapes the Gaussian beam into a flat-top beam, which uniformly illuminates the object being observed, providing the uniform background light required for imaging. The illumination lens C1 comprises two aspherical lenses arranged in a Galilean configuration, a structure that helps to shorten the lens length. The aspherical lenses can spatially modulate the energy distribution of the Gaussian beam, achieving a uniform distribution of light intensity at a specific location. The principle is as follows: Figure 2 As shown, Figure 2 middle P The intensity at the center of the fundamental mode Gaussian beam. W The width of the Gaussian beam waist. R The radius of the Gaussian beam. H This represents the average light intensity of a flat-top beam. D To output the beam radius of the flat-top beam, t Let be the coordinates of any ray on the incident plane of the Gaussian beam, and z be the coordinates of the ray from the corresponding exit plane of the flat-top beam. According to the law of conservation of energy, t Light energy within range and z The light energy within the range is equal, Gaussian beam t The light energy within the radius can be expressed as (1) Flat-top beam z The light energy within the radius is (2) because I 1( t )= I 2( z Therefore, there is (3) when t As the beam approaches infinity, the spot radius corresponding to the flat-top beam is obtained. D for (4) Substituting equation (4) into equation (3) yields the following result: z The coordinates of the ray and t The mapping relationship of the ray coordinates is as follows: (5) Optimize the radius of curvature values ​​of the two aspherical lenses so that z place and x If the light rays at the point satisfy the correspondence in equation (5) and ensure that the outgoing beam is parallel, the collimation and homogenization of the Gaussian beam can be achieved.

[0018] The first lens L1 is a plano-concave lens with negative optical power. Its function is to redistribute the energy distribution of the incident laser beam and expand the beam to the desired range. After being collimated, the Gaussian beam becomes a non-collimated beam with uniform energy at the position of the second lens L2. The second lens L2 is a plano-convex lens with positive optical power. Its function is to collimate the uniform beam incident on the surface, so that the uniformly energetic beam exits in parallel. The first lens L1 is flat facing the laser incident surface and concave facing the object surface. The incident light is a Gaussian beam with a very small divergence angle that is approximately parallel. The flat surface helps to reduce the angle at which the light enters the lens surface and avoids introducing aberrations. The concave surface is an aspherical surface, which diverges the beam and redistributes the energy of the beam so that it is uniformly incident on the second lens L2.

[0019] The second lens L2 has a convex surface facing the laser incident surface and a flat surface facing the object surface. The convex surface is an aspherical surface, which re-collimates the diverging uniform beam and sends it out in parallel. The collimated beam exiting from the convex surface is incident on the flat surface, and the flat surface does not change the energy distribution and collimation of the beam.

[0020] The imaging lens C2 comprises a front lens group G1, an aperture stop (STOP), and a rear lens group G2, arranged sequentially along the optical axis from the object side to the image side, in a positive-negative configuration. The front lens group G1 has positive optical power, and the rear lens group G2 has negative optical power. Light rays first converge through the positive front lens group G1 and then diverge through the negative rear lens group G2. This lens configuration also helps to shorten the lens length. The front lens group G1 includes a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8, wherein: The third lens L3 has a concave surface facing the object plane and a convex surface facing the image plane. The numerical aperture angle on the object plane side is larger. The surface near the object plane is curved towards the object plane, which helps to reduce the angle at which light rays are incident on the lens surface, thereby reducing the aberration of the system. The focal length of the third lens L3 is positive, which can reduce the incident angle of light rays incident on the surface of the fourth lens L4. The fourth lens L4 and the fifth lens L5 form the first group of cemented doublet lenses, with a positive focal length. The side of the fourth lens L4 facing the object plane is concave, and the side facing the image plane is convex, with a positive focal length. The fifth lens L5 has a concave side facing the object plane and a convex side facing the image plane, with a negative focal length. The sixth lens L6 and the seventh lens L7 form the second group of cemented doublets, with a positive focal length. In contrast to the first group of cemented doublets, the object-facing side of the sixth lens L6 is convex, and the image-facing side is concave, resulting in a negative focal length. The object-facing side of the seventh lens L7 is convex, and the image-facing side is also convex, with a positive focal length. The eighth lens L8 has a convex surface facing the object plane and a concave surface facing the image plane. Its focal length is positive, which further compresses the incident height of the light rays incident on the rear lens group G2. The front lens group G1 has four groups of six lenses arranged symmetrically. This structure helps to reduce aberrations. Both cemented doublets contain a convex lens with positive optical power and a concave lens with negative optical power. The cemented doublets are introduced to eliminate chromatic aberration. Although laser has good monochromaticity, its spectrum still has a certain width. Since the wavelength of the actual laser output light is not strictly monochromatic, correcting aberrations only for a certain wavelength will reduce the imaging performance of the lens. Therefore, cemented doublets are introduced to correct the small amount of chromatic aberration in the spectrum of the output laser.

[0021] The rear lens group G2 has a negative optical power, diverging the light rays converged by the front lens group G1, reducing the angle of incidence of the principal ray on the image plane, and improving the overall relative illumination of the lens. The rear lens group G2 includes the ninth lens L9 and the tenth lens L... 10 ,in: Ninth lens L9 and tenth lens L 10This forms the third group of cemented doublet lenses, with a negative focal length. The ninth lens, L9, has a concave surface facing both the object and image planes, and a negative focal length. The tenth lens, L... 10 The side facing the object plane is convex, the side facing the image plane is convex, the focal length is positive, and the use of cemented doublet lenses is still to correct a small amount of chromatic aberration in the system.

[0022] The present invention will be further described below with reference to two embodiments. In each embodiment, the radius of curvature and thickness of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments.

[0023] Example 1 The optical path diagram of this embodiment is as follows: Figure 3 As shown, the specifications of the lens group are listed in Table 1 below.

[0024] Table 1 Lens Group Specifications for Example 1 The specific parameters of the lens assembly in this embodiment are listed in Table 2 below.

[0025] Table 2 Lens assembly structural parameter values ​​for Example 1 In the illumination lens, surfaces S2 and S3 satisfy the formula for even-order aspherical surfaces. (6) In the formula, r Let be the radius of curvature of the surface. k These are the coefficients for the quadratic term; the aspherical coefficients are shown in Table 3.

[0026] Table 3 Aspherical coefficients S2 and S3 of the illumination lens surface in Example 1 Figure 4 This is a light energy distribution diagram of the illumination lens at the object surface in Embodiment 1 of the present invention. In the two-dimensional curve, the horizontal axis represents the position coordinates, and the vertical axis represents the energy density distribution. Figure 4 It can be seen that the Gaussian beam is well homogenized after passing through the illumination lens. The wavefront aberration of the illumination lens is as follows: Figure 5 As shown, by Figure 5 It can be seen that the wavefront aberration of the output beam is 0.05λ, indicating that the output beam is approximately parallel, thus achieving collimated output and transforming the Gaussian beam into a flat-top beam.

[0027] Figure 6This is a dot plot of the imaging lens in Embodiment 1 of the present invention. The dot plot represents the size of the geometric spot after a point light source passes through the optical lens. It can be used to evaluate the optical lens in the spatial domain. The smaller the size of the geometric spot in the dot plot, the better the aberration correction of the optical lens, and the stronger the lens's object resolution capability. Figure 6 It can be seen that the maximum geometric radius of the lens spot is 2.83µm, and the Airy disk radius is 3.48µm. The spots of all fields of view in the dot plot are within the Airy disk, indicating that the aberration correction of each field of view of the lens is good.

[0028] Figure 7 This is a modulation transfer function (MTF) curve of the imaging lens in Embodiment 1 of the present invention. In the spatial domain, the imaging lens can be evaluated using a dot plot. In the frequency domain, the imaging quality of the lens can be evaluated using the MTF, which describes the system's ability to transfer contrast across various frequency components. A higher MTF value indicates better lens performance. Figure 7 It can be seen that the MTF curves of the lens in each field of view are close to the diffraction limit, indicating that the lens has good performance.

[0029] Example 2 The optical path diagram of this embodiment is as follows: Figure 8 As shown, the specifications of the lens group are listed in Table 4 below.

[0030] Table 4 Lens group specifications for Example 2 The specific parameters of the lens assembly in this embodiment are shown in Table 5 below.

[0031] Table 5 Lens assembly structural parameter values ​​for Example 2 The surfaces S2 and S3 in the illumination lens satisfy the even-order aspherical formula (6), and the aspherical coefficients are shown in Table 6.

[0032] Table 6 Aspherical coefficients S2 and S3 of the illumination lens surface in Example 2 Figure 9 This is a light energy distribution diagram of the illumination lens at the object surface position in Embodiment 2 of the present invention. Figure 9 It can be seen that the Gaussian beam is well homogenized after passing through the illumination lens. The wavefront aberration of the illumination lens is as follows: Figure 10 As shown, by Figure 10 It can be seen that the wavefront aberration of the output beam is 0.05λ, indicating that the output beam is approximately parallel, thus achieving collimated output of the beam and transforming the Gaussian beam into a flat-top beam.

[0033] Figure 11This is a dot diagram of the imaging lens in Embodiment 2 of the present invention, by... Figure 11 It can be seen that the maximum geometric radius of the lens spot is 1.75µm, and the Airy disk radius is 4.36µm. The spots of all fields of view in the dot plot are within the Airy disk, indicating that the aberration correction of each field of view of the lens is good.

[0034] Figure 12 This is a modulation transfer function (MTF) curve of the imaging lens in Embodiment 2 of the present invention. Figure 12 It can be seen that the MTF curves of the lens in each field of view are close to the diffraction limit, indicating that the lens has good resolving power.

[0035] In summary, this invention optimizes the design of an illumination lens and an imaging lens based on a laser light source. The lens assembly is designed specifically for the characteristics of laser light. The illumination lens can shape a Gaussian beam into a flat-top beam, exhibiting excellent beam homogenization and collimation effects. Compared to LED light sources, the stroboscopic laser illumination beam has a shorter pulse width and higher energy, solving the problem of motion blur in high-speed moving objects. The imaging lens maintains high spatial resolution even at long working distances, enabling clear imaging of small objects and addressing the low resolution issue of existing shadow imaging systems. This improves the observation capabilities of shadow imaging systems and expands their application scenarios.

[0036] The parts of this invention not described in detail are well-known in the field.

[0037] The above description is only a part of the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A laser illumination and imaging lens group for a shadow imaging system, characterized in that, The illumination lens C1 and the imaging lens C2 are coaxially arranged, the illumination lens C1 is located at the laser light source side and is used for shaping a Gaussian light beam output by a monochromatic laser into a collimated flat-top light beam and irradiating an object to be measured located behind the illumination lens C1, and the imaging lens C2 is located at an image side and is used for receiving and converging a light beam after being blocked by the object to be measured to form a high-resolution shadow image of the object to be measured on an image plane; The illumination lens C1 sequentially comprises a first lens L1 with negative optical power and a second lens L2 with positive optical power along an optical path, and surface type parameters of the first aspheric lens L1 and the second aspheric lens L2 satisfy an energy redistribution mapping relationship from a Gaussian light beam to a flat-top light beam; The imaging lens C2 comprises, in sequence from the object side to the image side along the optical path, a front lens group G1 with positive refractive power, a stop STOP and a rear lens group G2 with negative refractive power, wherein the front lens group G1 is mainly used for converging light rays and correcting aberrations, and is composed of six spherical lenses, i.e., a third lens L3 with positive refractive power, a first cemented lens composed of a fourth lens L4 with positive refractive power and a fifth lens L5 with negative refractive power, a second cemented lens composed of a sixth lens L6 with negative refractive power and a seventh lens L7 with positive refractive power, and an eighth lens L8 with positive refractive power; the rear lens group G2 is used for adjusting the chief ray angle to improve the uniformity of image plane illumination, and cooperates with the front lens group G1 to achieve an optical resolution of microns at a working distance greater than 100 mm, and is composed of a third double cemented lens composed of two spherical lenses, i.e., a ninth lens L9 with negative refractive power and a tenth lens L10 with positive refractive power. 10 .

2. The laser illumination and imaging lens according to claim 1, wherein, The lenses of the illumination lens C1 are all aspherical lenses, wherein the first lens L1 is a plano-concave lens with negative focal power, one side facing the laser source side is a plane, and one side facing the object plane is a concave surface, the focal length of the first lens L1 is 1.5-2.5 times the focal length of the second lens L2, and the focal length of the second lens L2 is 1.5-2.5 times the focal length of the third lens L3. f 1<0; The second lens L2 is a plano-convex lens having a positive focal power, the side toward the laser source is a convex surface, and the side toward the object plane is a plane. The focal length of the second lens L2 is f 2 0.

3. The laser illumination and imaging lens according to claim 1, wherein, The power of the front lens group G1 φ 1 0, the power of the rear lens group G2 φ 2<0. 4.The laser illumination and imaging lens assembly head according to claim 1 or 3, wherein, The imaging lens C2 satisfies the following relationship: The third lens L3 has a concave surface on the object side and a convex surface on the image side, 110 mm f 3 205 mm, 1.71 Nd 3 1.80, 45 Vd 3 60; The fourth lens L4 has a concave surface on the object side and a convex surface on the image side, 141 mm f 4 200 mm, 1.45 Nd 4 1.56, 65 Vd 4 75; The fifth lens L5 has a concave surface on the object side and a convex surface on the image side, -171 mm f 5 <-127 mm, 1.76 Nd 5 <1.90, 20 Vd 5 <30; The sixth lens L6 has a convex surface on the object side and a concave surface on the image side, -336mm f 6 <-155mm, 1.72 Nd 6 <1.85, 36 Vd 6 <45; The seventh lens L7 has a convex surface on the object side and a convex surface on the image side, 152 mm f 7 251 mm, 1.45 Nd 7 1.56, 65 Vd 7 75; The eighth lens L8 is convex on the object side and concave on the image side, 149mm f 8 234mm, 1.75 Nd 8 1.80, 45 Vd 8 55; The ninth lens L9 has a concave surface on the object side and a concave surface on the image side, -45mm f 9 <- 15mm, 1.48 Nd 9 < 1.60, 55 Vd 9 < 65; The tenth lens L 10 Convex on the object side and convex on the image side, 30 mm f 10 <60 mm, 1.59 Nd 10 <1.65, 55 Vd 10 <65; wherein f 3 is a focal length of the third lens L3, Nd 3 is a refractive index of the third lens L3, Vd 3 is an Abbe number of the third lens L3, f 4 is a focal length of the fourth lens L4, Nd 4 is a refractive index of the fourth lens L4, Vd 4 is an Abbe number of the fourth lens L4, f 5 is a focal length of the fifth lens L5, Nd 5 is a refractive index of the fifth lens L5, Vd 5 is an Abbe number of the fifth lens L5, f 6 is a focal length of the sixth lens L6, Nd 6 is a refractive index of the sixth lens L6, Vd 6 is an Abbe number of the sixth lens L6, f 7 is a focal length of the seventh lens L7, Nd 7 is a refractive index of the seventh lens L7, Vd 7 is an Abbe number of the seventh lens L7, f 8 is a focal length of the eighth lens L8, Nd 8 is a refractive index of the eighth lens L8, Vd 8 is an Abbe number of the eighth lens L8, f 9 is a focal length of the ninth lens L9, Nd 9 is a refractive index of the ninth lens L9, Vd 9 is an Abbe number of the ninth lens L9, f 10 is a focal length of the tenth lens L 10 , Nd 10 is a refractive index of the tenth lens L 10 , Vd 10 is an Abbe number of the tenth lens L 10 .

5. The laser illumination and imaging lens according to any of claims 1-4, wherein, Nd Working distance of the illumination lens C1 Vd 1 ≥ 10 mm, illumination range The working wavelengths of the illumination lens C1 and the imaging lens C2 are monochromatic light; 1 ≤ 6 mm; Working distance of the imaging lens C2 WD 2 ≤ 110 mm, optical resolution on the object side Φ ≥ 1 µm, imaging field of view WD δ Φ 2 ≤ 4.76 mm.

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