Laser beam expansion collimating lens set and microscopic imaging device

Abstract

The utility model relates to a laser beam expansion collimating lens group and a microscopic imaging device, comprising: a biconcave lens, a plano-concave lens, a biconvex lens and a plano-convex lens arranged in sequence along the light beam propagation path. The laser beam expansion collimating lens group disclosed in the utility model can not only significantly expand the laser beam diameter, but also effectively collimate the beam and ensure the uniformity of the laser spot while maintaining a relatively simplified system design, so as to meet various application requirements requiring a large area and high uniformity laser spot.

Description

Technical Field

[0001] The utility model relates to the technical field of optical instruments, in particular to a laser beam expansion and collimation lens group and a microscopic imaging device. Background Art

[0002] In the current optical field, lasers are widely used in many fields such as industrial processing, communications, scientific research, and medical treatment due to their high intensity, high parallelism, and high wavelength stability. However, in order to meet the special requirements for laser spot size and uniformity in different application scenarios, it is usually necessary to expand the original laser beam (increase the lateral size of the laser beam) and collimate (convert the divergent beam into parallel light). Therefore, laser beam expansion and collimation technology has become a key research direction.

[0003] In practical applications, the laser beam expansion and collimation system needs to increase the beam diameter while maintaining high uniformity of the beam, and the design should be simplified as much as possible to reduce the system volume. However, it is difficult for existing technical solutions to provide a laser spot with both large area and high uniformity without complicating the system design. Utility Model Content

[0004] The utility model aims to provide a laser beam expansion and collimation lens group to solve the above-mentioned problems.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] On the one hand, the present application provides a laser beam expansion and collimation lens group, including: a biconcave lens, a plano-concave lens, a biconvex lens, and a plano-convex lens arranged in sequence along a beam propagation path.

[0007] Optionally, the biconcave lens has a thickness of 2.9 mm to 3.1 mm, a front surface curvature radius of -53 mm to -52 mm, and a rear surface curvature radius of 52 mm to 53 mm;

[0008] The thickness of the plano-concave lens is 3.4 mm to 3.6 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is 25 mm to 26 mm;

[0009] The thickness of the biconvex lens is 9.4 mm to 9.6 mm, the radius of curvature of the front surface is 101 mm to 102 mm, and the radius of curvature of the rear surface is -102 mm to -101 mm;

[0010] The thickness of the plano-convex lens is 9.6 mm to 9.8 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is -51 mm to -50 mm;

[0011] Among them, the air gap between the biconcave lens and the plano-concave lens is 33mm-34mm, the air gap between the plano-concave lens and the biconvex lens is 14mm-15mm, and the air gap between the biconvex lens and the plano-convex lens is 16mm-17mm.

[0012] Optionally, the biconcave lens has a thickness of 3.0 mm, a front surface curvature radius of -52.2 mm, and a rear surface curvature radius of 52.2 mm;

[0013] The thickness of the plano-concave lens is 3.5 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is 25.4 mm;

[0014] The thickness of the biconvex lens is 9.5 mm, the radius of curvature of the front surface is 101.5 mm, and the radius of curvature of the rear surface is -101.5 mm;

[0015] The thickness of the plano-convex lens is 9.7 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is -50.5 mm;

[0016] The air gap between the biconcave lens and the plano-concave lens is 33.4 mm, the air gap between the plano-concave lens and the biconvex lens is 14.5 mm, and the air gap between the biconvex lens and the plano-convex lens is 16.2 mm.

[0017] The biconcave lens, the plano-concave lens, the biconvex lens and the plano-convex lens are all made of N-BK7 material.

[0018] Optionally, the laser beam expansion and collimation lens assembly further includes a first lens mounting barrel and a second lens mounting barrel that are detachably connected, and the diameter of the first lens mounting barrel is smaller than the diameter of the main body of the second lens mounting barrel;

[0019] The biconcave lens is arranged in the first lens mounting tube, and the plano-concave lens, the biconvex lens and the plano-convex lens are arranged in sequence in the second lens mounting tube.

[0020] Optionally, one end of the first lens mounting tube is an incident end for receiving a laser beam;

[0021] A first positioning ring is provided on the inner wall of the incident end of the first lens mounting tube, and a first fixing ring is threadedly connected to the inner wall of the incident end of the first lens mounting tube, wherein the first fixing ring is arranged at a position close to the incident end port, and the first positioning ring and the first fixing ring are used to jointly fix the biconcave lens.

[0022] Optionally, one end of the second lens mounting tube is a connecting end, and the connecting end is threadedly connected to the other end of the first lens mounting tube;

[0023] A second positioning ring is provided on the inner wall of the connecting end of the second lens mounting tube, and a second fixing ring is threadedly connected to the inner wall of the connecting end of the second lens mounting tube, wherein the second fixing ring is arranged at a position close to the connecting end port, and the second positioning ring and the second fixing ring are used to jointly fix the plano-concave lens.

[0024] Optionally, the other end of the second lens mounting tube is an emission end for emitting a laser beam;

[0025] A third positioning ring is provided on the inner wall of the emission end of the second lens mounting tube, and a third fixing ring is threadedly connected on the inner wall of the emission end of the second lens mounting tube, wherein the third fixing ring is arranged at a position close to the emission end port;

[0026] The biconvex lens, the spacer ring, and the plano-convex lens are arranged in sequence between the third positioning ring and the third fixing ring.

[0027] On the other hand, the present application provides a microscopic imaging device, comprising the above-mentioned laser beam expansion and collimation lens group, and also comprising a fiber coupler and an XY adjustment frame;

[0028] The optical fiber coupler is fixed on one side of the XY adjustment frame, and the laser beam expansion collimation lens group is fixed on the other side of the XY adjustment frame.

[0029] Compared with the prior art, the utility model has the following beneficial effects:

[0030] A biconcave lens is a lens with two inward concave surfaces, which is used to diverge the incoming laser beam; a plano-concave lens has one side that is flat and the other side that is concave, which is used to further diverge the light beam and control the degree of light beam divergence. Compared with a biconcave lens, a plano-concave lens has a milder divergence effect and can accurately adjust the divergence angle of the light beam; a biconvex lens is a lens with two outward convex surfaces, which is mainly used to converge the light beam, that is, to re-gather the light diverged by the front lens. By adjusting the curvature and position of the biconvex lens, the divergent light beam can be re-collimated; a plano-convex lens has one side that is flat and the other side that is convex, which is used to further fine-tune and collimate the light beam. The laser beam expansion and collimation lens group provided by the present invention, through the combination and configuration of a biconcave lens, a plano-concave lens, a biconvex lens and a plano-convex lens, can not only significantly expand the diameter of the laser beam, but also effectively collimate the light beam and ensure the uniformity of the laser spot while maintaining a relatively simplified system design, so as to meet various application requirements requiring a large area and high uniformity laser spot. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0033] Figure 1 is a cross-sectional view of the laser beam expansion and collimation lens assembly in this embodiment;

[0034] Figure 2 An exploded view of the laser beam expansion and collimation lens assembly in this embodiment;

[0035] Figure 3 Schematic diagram of the optical path of the laser beam expansion and collimation lens group in this embodiment;

[0036] Figure 4 is an application schematic diagram of the microscopic imaging device in this embodiment;

[0037] Figure 5 This is a light path layout diagram of the laser beam expansion and collimation lens group in this embodiment;

[0038] Figure 6 is a diagram of incident angle vs. image height of the laser beam expansion and collimation lens group in this embodiment;

[0039] Figure 7 This is a simulation diagram of the illumination of the laser beam expansion and collimation lens group in this embodiment;

[0040] Description of reference numerals:

[0041] 11. Biconcave lens; 12. Plano-concave lens; 13. Biconvex lens; 14. Plano-convex lens;

[0042] 21, first lens mounting tube; 211, first positioning ring; 22, second lens mounting tube; 221, second positioning ring; 222, third positioning ring;

[0043] 31. First fixing ring; 32. Second fixing ring; 33. Third fixing ring; 34. Spacer ring;

[0044] 41. Fiber optic coupler; 42. XY adjustment frame. DETAILED DESCRIPTION

[0045] In order to make the utility model's purpose, features, and advantages more obvious and easy to understand, the following will be combined with the drawings in the utility model embodiments to clearly and completely describe the technical solutions in the utility model embodiments. Obviously, the embodiments described below are only part of the utility model embodiments, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0047] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0048] Reference Figures 1 to 7 The laser beam expansion and collimation lens group disclosed in this embodiment includes: a biconcave lens 11, a plano-concave lens 12, a biconvex lens 13 and a plano-convex lens 14 arranged in sequence along the beam propagation path.

[0049] The biconcave lens 11 is a lens with two inward concave surfaces, which is used to diverge the incoming laser beam; one side of the plano-concave lens 12 is flat, and the other side is concave, which is used to further diverge the light beam and control the degree of light beam divergence. Compared with the biconcave lens 11, the divergence effect of the plano-concave lens 12 is milder, and the divergence angle of the light beam can be accurately adjusted; the biconvex lens 13 is a lens with two outward convex surfaces, which is mainly used to converge the light beam, that is, to re-gather the light diverged by the previous lens. By adjusting the curvature and position of the biconvex lens 13, the divergent light beam can be re-collimated; one side of the plano-convex lens 14 is flat, and the other side is convex, which is used to further fine-tune and collimate the light beam. The laser beam expansion and collimating lens group provided by the present invention, through the combination and configuration of a biconcave lens 11, a plano-concave lens 12, a biconvex lens 13 and a plano-convex lens 14, can not only significantly expand the diameter of the laser beam while maintaining a relatively simplified system design, but also effectively collimate the beam and ensure the uniformity of the laser spot, so as to meet various application requirements that require a large-area and highly uniform laser spot.

[0050] Preferably, the thickness of the biconcave lens 11 is 2.9mm-3.1mm, the radius of curvature of the front surface is -53mm--52mm, and the radius of curvature of the rear surface is 52mm-53mm; the thickness of the plano-concave lens 12 is 3.4mm-3.6mm, the radius of curvature of the front surface is infinite (i.e., a plane), and the radius of curvature of the rear surface is 25mm-26mm; the thickness of the biconvex lens 13 is 9.4mm-9.6mm, the radius of curvature of the front surface is 101mm-102mm, and the radius of curvature of the rear surface is -102mm--101mm; the thickness of the plano-convex lens 14 is 9.6mm-9.8mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is -51mm--50mm;

[0051] Among them, the air gap between the biconcave lens 11 and the plano-concave lens 12 is 33 mm to 34 mm, the air gap between the plano-concave lens 12 and the biconvex lens 13 is 14 mm to 15 mm, and the air gap between the biconvex lens 13 and the plano-convex lens 14 is 16 mm to 17 mm.

[0052] More preferably, the thickness of the biconcave lens 11 is 3.0 mm, the radius of curvature of the front surface is -52.2 mm, and the radius of curvature of the rear surface is 52.2 mm; the thickness of the plano-concave lens 12 is 3.5 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is 25.4 mm; the thickness of the biconvex lens 13 is 9.5 mm, the radius of curvature of the front surface is 101.5 mm, and the radius of curvature of the rear surface is -101.5 mm; the thickness of the plano-convex lens 14 is 9.7 mm , the front surface curvature radius is infinite, and the rear surface curvature radius is -50.5mm; wherein, the air gap between the biconcave lens 11 and the plano-concave lens 12 is 33.4mm, the air gap between the plano-concave lens 12 and the biconvex lens 13 is 14.5mm, and the air gap between the biconvex lens 13 and the plano-convex lens 14 is 16.2mm; wherein, the biconcave lens 11, the plano-concave lens 12, the biconvex lens 13 and the plano-convex lens 14 are all made of N-BK7 material.

[0053] N-BK7 is an optical glass material, a type of borosilicate glass, produced and sold by Schott AG. The following are the important characteristics of N-BK7 optical glass: 1. Excellent optical transparency: N-BK7 has high optical transparency from short wavelength to near infrared band, so it is suitable for transmitting visible light and near infrared light; 2. High refractive index and low dispersion: Compared with other optical materials, N-BK7 has a relatively high refractive index (about 1.517 at 587.6 nm) and low dispersion (Abbe number is about 64), which means that it can effectively focus or collimate the light beam while reducing chromatic aberration; 3. Thermal stability: N-BK7 has a relatively small thermal expansion coefficient and good thermal stability, which makes the optical performance not change much in the environment of temperature change; 4. Chemical resistance: N-BK7 has good chemical resistance and can resist the erosion of many chemicals, making it easy to clean and maintain; 5. Abrasion resistance: This glass has a high hardness and good abrasion resistance, so it is not easy to be scratched in daily use.

[0054] like Figure 5 The optical path layout shown shows that good collimation performance is achieved within 0~700mm.

[0055] like Figure 6 The incident angle vs. image height plot shown shows that the maximum incident angle is within 0.1 degrees.

[0056] like Figure 7 The illumination simulation diagram shown shows that the uniformity of the laser spot within Ø40mm is greater than 80%.

[0057] Reference Figures 1 to 3 The laser beam expansion collimating lens group also includes a first lens mounting barrel 21 and a second lens mounting barrel 22 which are detachably connected. The diameter of the first lens mounting barrel 21 is smaller than the diameter of the main body of the second lens mounting barrel 22. The biconcave lens 11 is arranged in the first lens mounting barrel 21, and the plano-concave lens 12, the biconvex lens 13 and the plano-convex lens 14 are arranged in the second lens mounting barrel 22 in sequence. The first lens mounting barrel 21 and the second lens mounting barrel 22 ensure the relative position and optical axis alignment of each lens, and reduce the beam quality problem caused by the lens position offset; the detachable connection design facilitates assembly and disassembly, and is conducive to the maintenance, replacement and cleaning of the lens.

[0058] Reference Figures 1 to 3One end of the first lens mounting tube 21 is the incident end, which is used to receive the laser beam; a first positioning ring 211 is provided on the inner wall of the incident end of the first lens mounting tube 21, and a first fixing ring 31 is threadedly connected to the inner wall of the incident end of the first lens mounting tube 21, wherein the first fixing ring 31 is arranged at a position close to the incident end port, and the first fixing ring 211 and the first positioning ring 31 are used to jointly fix the biconcave lens 11.

[0059] The first positioning ring 211 is integrally formed with the first lens mounting barrel 21, and is used to preliminarily fix the position of the biconcave lens 11, ensuring the correct position and angle of the biconcave lens 11 in the first lens mounting barrel 21. During installation, the biconcave lens 11 is loaded from the port at the incident end of the first lens mounting barrel 21, and one side of the biconcave lens 11 abuts against the first positioning ring 211 to be preliminarily fixed, and then the first fixing ring 31 is screwed in to abut against the other side of the biconcave lens 11 to completely fix the biconcave lens 11. The threaded connection design makes the maintenance and replacement of the biconcave lens 11 easier.

[0060] Reference Figures 1 to 3 One end of the second lens mounting tube 22 is a connecting end, and the connecting end is threadedly connected to the other end of the first lens mounting tube 21; a second positioning ring 221 is provided on the inner wall of the connecting end of the second lens mounting tube 22, and a second fixing ring 32 is threadedly connected on the inner wall of the connecting end of the second lens mounting tube 22, wherein the second fixing ring 32 is arranged at a position close to the connecting end port, and the second positioning ring 221 and the second fixing ring 32 are used to jointly fix the plano-concave lens 12.

[0061] Reference Figures 1 to 3 The other end of the second lens mounting tube 22 is an output end for emitting a laser beam; a third positioning ring 222 is provided on the inner wall of the output end of the second lens mounting tube 22, and a third fixing ring 33 is threadedly connected on the inner wall of the output end of the second lens mounting tube 22, wherein the third fixing ring 33 is arranged at a position close to the output port; a biconvex lens 13, a spacer ring 34, and a plano-convex lens 14 are arranged in sequence between the third positioning ring 222 and the third fixing ring 33, and the spacer ring 34 is arranged between the biconvex lens 13 and the plano-convex lens 14 to provide physical isolation and ensure an appropriate spacing between the two lenses.

[0062] The installation process of the plano-concave lens 12 , the biconvex lens 13 and the plano-convex lens 14 is similar to that of the biconcave lens 11 , and will not be described in detail here.

[0063] Reference Figure 4 This embodiment also discloses a microscopic imaging device, including the above-mentioned laser beam expansion and collimation lens group, and also includes a fiber coupler 41 and an XY adjustment frame 42; the fiber coupler 41 is fixed to one side of the XY adjustment frame 42, and the laser beam expansion and collimation lens group is fixed to the other side of the XY adjustment frame 42.

[0064] The fiber coupler 41 is used to effectively transmit the laser beam from the optical fiber to the laser beam expansion and collimation lens group, ensuring that the intensity and quality of the beam are not significantly lost during the transmission process; the XY adjustment frame 42 is used to adjust the position and angle of the fiber coupler 41 to achieve precise adjustment of the beam incident angle and beam path, ensuring that the beam can be optimally expanded and collimated through the lens group; as described above, the laser beam expansion and collimation lens group is used to expand and collimate the laser beam, providing a large area and highly uniform laser spot. In the microscopic imaging device, after the laser beam is expanded and collimated, it can be evenly and stably irradiated onto the sample to improve the imaging quality.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser beam expansion and collimation lens assembly, characterized in that: include: A biconcave lens (11), a plano-concave lens (12), a biconvex lens (13), and a plano-convex lens (14) are sequentially arranged along the light beam propagation path; The biconcave lens (11) has a thickness of 2.9 mm to 3.1 mm, a front surface curvature radius of -53 mm to -52 mm, and a rear surface curvature radius of 52 mm to 53 mm; The thickness of the plano-concave lens (12) is 3.4 mm to 3.6 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is 25 mm to 26 mm; The biconvex lens (13) has a thickness of 9.4 mm to 9.6 mm, a front surface curvature radius of 101 mm to 102 mm, and a rear surface curvature radius of -102 mm to -101 mm; The thickness of the plano-convex lens (14) is 9.6 mm to 9.8 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is -51 mm to -50 mm; The air gap between the biconcave lens (11) and the plano-concave lens (12) is 33 mm to 34 mm, the air gap between the plano-concave lens (12) and the biconvex lens (13) is 14 mm to 15 mm, and the air gap between the biconvex lens (13) and the plano-convex lens (14) is 16 mm to 17 mm.

2. The laser beam expansion and collimation lens assembly according to claim 1, characterized in that: The biconcave lens (11) has a thickness of 3.0 mm, a front surface curvature radius of -52.2 mm, and a rear surface curvature radius of 52.2 mm; The thickness of the plano-concave lens (12) is 3.5 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is 25.4 mm; The biconvex lens (13) has a thickness of 9.5 mm, a front surface curvature radius of 101.5 mm, and a rear surface curvature radius of -101.5 mm; The thickness of the plano-convex lens (14) is 9.7 mm, the radius of curvature of the front surface is infinite, and the radius of curvature of the rear surface is -50.5 mm; The air gap between the biconcave lens (11) and the plano-concave lens (12) is 33.4 mm, the air gap between the plano-concave lens (12) and the biconvex lens (13) is 14.5 mm, and the air gap between the biconvex lens (13) and the plano-convex lens (14) is 16.2 mm. The biconcave lens (11), the plano-concave lens (12), the biconvex lens (13) and the plano-convex lens (14) are all made of N-BK7 material.

3. The laser beam expansion and collimation lens assembly according to claim 1, characterized in that: It also comprises a first lens mounting barrel (21) and a second lens mounting barrel (22) which are detachably connected, the diameter of the first lens mounting barrel (21) being smaller than the diameter of the main body of the second lens mounting barrel (22); The biconcave lens (11) is arranged in the first lens mounting tube (21), and the plano-concave lens (12), the biconvex lens (13) and the plano-convex lens (14) are arranged in sequence in the second lens mounting tube (22).

4. The laser beam expansion and collimation lens assembly according to claim 3, characterized in that: One end of the first lens mounting tube (21) is an incident end, used for receiving a laser beam; A first positioning ring (211) is provided on the inner wall of the incident end of the first lens mounting tube (21), and a first fixing ring (31) is threadedly connected to the inner wall of the incident end of the first lens mounting tube (21), wherein the first fixing ring (31) is arranged at a position close to the incident end port, and the first positioning ring (211) and the first fixing ring (31) are used to jointly fix the biconcave lens (11).

5. The laser beam expansion and collimation lens assembly according to claim 4, characterized in that: One end of the second lens mounting tube (22) is a connecting end, and the connecting end is threadedly connected to the other end of the first lens mounting tube (21); A second positioning ring (221) is provided on the inner wall of the connecting end of the second lens mounting tube (22), and a second fixing ring (32) is threadedly connected to the inner wall of the connecting end of the second lens mounting tube (22), wherein the second fixing ring (32) is arranged at a position close to the connecting end port, and the second positioning ring (221) and the second fixing ring (32) are used to jointly fix the plano-concave lens (12).

6. The laser beam expansion and collimation lens assembly according to claim 5, characterized in that: The other end of the second lens mounting tube (22) is an emission end, used for emitting a laser beam; A third positioning ring (222) is provided on the inner wall of the emission end of the second lens mounting tube (22), and a third fixing ring (33) is threadedly connected to the inner wall of the emission end of the second lens mounting tube (22), wherein the third fixing ring (33) is arranged at a position close to the emission end port; The double convex lens (13), a spacer ring (34), and the plano-convex lens (14) are sequentially arranged between the third positioning ring (222) and the third fixing ring (33).

7. A microscopic imaging device, characterized in that: A laser beam expansion and collimation lens assembly comprising any one of claims 1 to 6, further comprising a fiber coupler (41) and an XY adjustment frame (42); The optical fiber coupler (41) is fixed to one side of the XY adjustment frame (42), and the laser beam expansion and collimation lens group is fixed to the other side of the XY adjustment frame (42).

Images