Compact laser beam expander

Abstract

According to the compact laser beam expanding lens, a beam expanding cylinder part, an adjusting cylinder part, a transmitting cylinder part and an axial sleeve are integrally formed, and an integrated mounting cylinder design is adopted, so that the boundary dimension and the total length of the beam expanding lens are greatly reduced, and the overall structure is more compact; the first lens, the second lens and the third lens are all fixed in the first lens barrel and the second lens barrel at a time through cooperation of the preset step parts and the adhesive layers, complex thread adjustment or centering operation is not needed, and the assembly process is simplified; the second lens barrel can slide in the adjusting barrel portion in the axial direction, continuous fine adjustment is achieved through cooperation of a strip-shaped groove hole and a fastening bolt, accurate optimization of the beam expanding multiplying power and the light beam collimation degree is guaranteed, and rapid locking and repeated positioning can be achieved. The optical axes of the first lens, the second lens, the third lens and the laser transmitter strictly coincide with the central axis of each cylinder part, so that the optical consistency of the system is improved.

Description

Technical Field

[0001] This application relates to the field of laser equipment technology, and more specifically to a compact laser beam expander. Background Technology

[0002] A laser beam expander is an optical device used to expand the diameter of a laser beam and reduce its divergence angle. It is commonly used in long-distance lighting, laser projection, laser communication, and focusing systems. By shaping and collimating the laser beam using a beam expander, the energy concentration and imaging accuracy of the laser system during long-distance transmission can be improved, which is of great significance for enhancing the overall system performance.

[0003] Existing laser beam expanders typically employ optical systems composed of multiple lens groups, achieving the required beam magnification and low divergence angle through precisely designed curvature and spacing. In terms of optical performance, current technologies have already achieved a certain level of high beam magnification, low optical loss, and high transmittance. However, besides optimizing the optical system itself, the mechanical assembly structure of the laser beam expander is also a key factor affecting its overall performance and practical application effectiveness.

[0004] In existing technologies, laser beam expanders are typically assembled from multiple linearly arranged lens assemblies. To ensure optical axis consistency and structural stability, they are often encapsulated in large-sized metal shells. While this structure facilitates the adjustment and fixation of optical components, it also results in a large overall size and weight of the beam expander. Especially in applications with high requirements for space, ease of installation, or portability (such as portable laser devices, UAV laser rangefinders, and compact optical platforms), the size and weight of existing beam expanders become the main factors limiting their application range.

[0005] Therefore, optimizing the structural design of laser beam expanders to achieve miniaturization, lightweighting, and high integration while ensuring beam expansion ratio and optical performance has become a pressing technical problem in this field. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the purpose of this application is to provide a compact laser beam expander to solve the problems mentioned in the background art.

[0007] According to one aspect of this application, a compact laser beam expander includes a base, an integrated mounting cylinder, a first lens barrel, a second lens barrel, a first lens, a second lens, a third lens, and a laser emitter. The integrated mounting cylinder is fixedly mounted on the base. The first lens barrel is fixedly mounted at the front end of the integrated mounting cylinder. The second lens barrel is adjustablely mounted at the middle of the integrated mounting cylinder. The laser emitter is fixedly mounted at the rear end of the integrated mounting cylinder. The first lens and the second lens are fixedly mounted sequentially from front to back on the first lens barrel. The third lens is fixedly mounted on the second lens barrel. The optical axes of the first lens, the second lens, the third lens, and the laser emitter coincide. The first lens, the second lens, and the third lens are all fixedly mounted in the first lens barrel and the second lens barrel respectively by adhesive layers.

[0008] Preferably, the integrated mounting tube includes a beam expander section, an adjustment section, and a emitting section. The front end of the beam expander section is open, and the first lens tube is fixedly installed inside the beam expander section through the front end opening. The rear end of the beam expander section is fixedly connected to the front end of the adjustment section. The second lens tube is slidably installed inside the adjustment section. A fastening bolt is threaded onto the outer wall of the second lens tube, and the second lens tube can be fixedly connected to the adjustment section through the fastening bolt after the position of the second lens tube is adjusted. The rear end of the adjustment section is fixedly connected to the front end of the emitting section. An axial sleeve is fixedly provided inside the emitting section along its axial direction. The shape and size of the inner sidewall of the axial sleeve are adapted to the shape and size of the outer sidewall of the laser emitter. The laser emitter is fixedly installed inside the axial sleeve.

[0009] Preferably, the central axes of the adjusting cylinder and the emitting cylinder coincide, the central axis of the first lens barrel coincides with the central axis of the beam expander, the central axis of the second lens barrel coincides with the central axis of the adjusting cylinder, and the optical axes of the first lens, the second lens, the third lens, and the laser emitter coincide with the central axes of the beam expander, the adjusting cylinder, and the emitting cylinder.

[0010] Preferably, a first step and a second step are sequentially formed on the inner sidewall of the first lens barrel along its axial direction. The diameter of the opening at the front end of the first lens barrel is larger than the diameter of the first step, the diameter of the first step is larger than the diameter of the second step, and the diameter of the second step is larger than the diameter of the opening at the rear end of the first lens barrel. A third step is formed on the inner sidewall of the opening at one end of the second lens barrel. The inner sidewall of the first step and the outer sidewall of the first lens, the inner sidewall of the second step and the outer sidewall of the second lens, and the inner sidewall of the third step and the outer sidewall of the third lens are all fixedly connected by the adhesive layer.

[0011] Preferably, the front end of the first lens barrel is inserted into the interior of the beam expander section and the side walls of the two are in contact. The outer side wall of the front end of the first lens barrel is provided with a flange and is fixedly connected to the front opening of the beam expander section by screws. The rear end of the first lens barrel is inserted into the interior front end of the adjustment section and the side walls of the two are in contact. A fixing plate is also fixedly provided on the outer side wall of the rear end of the first lens barrel. The outer side wall of the fixing plate is in contact with the inner side wall of the beam expander section and a plurality of connecting bolts are provided at equal intervals along its circumference and are fixedly connected to the beam expander section by threaded connection.

[0012] Preferably, a strip-shaped slot is provided through the side wall of the adjusting cylinder along its axial direction, and the fastening bolt is threaded through the strip-shaped slot and connected to the outer side wall of the second lens barrel. An installation groove is also provided at the outer opening edge of the strip-shaped slot, and a dust cover is embedded in the installation groove. The dust cover is used to cover the fastening bolt and the strip-shaped slot.

[0013] Preferably, connecting ears are fixedly provided on both the left and right sides of the rear end of the laser emitter. After the laser emitter is installed in the axial sleeve, the laser emitter is fixedly connected to the rear end of the emitter tube by screws passing through the connecting ears.

[0014] Preferably, the upper and lower outer sidewalls of the laser emitter are provided with positioning grooves along their axial direction, and the upper and lower inner sidewalls of the axial sleeve are fixedly provided with positioning protrusions along their axial direction. The positioning grooves are adapted to the positioning protrusions. When the laser emitter is placed inside the axial sleeve, the positioning protrusions are placed in the positioning grooves.

[0015] Preferably, the beam expander, the adjusting tube, the launching tube, and the axial sleeve are integrally formed.

[0016] The advantages of this application compared with the prior art are as follows: This application provides a compact laser beam expander, which integrates the beam expander tube, adjusting tube, emitting tube, and axial sleeve into a single unit, employing an integrated mounting tube design. This significantly reduces the external dimensions and overall length of the beam expander, resulting in a more compact overall structure. The first, second, and third lenses are all fixed in one piece within the first and second lens tubes via pre-set steps and adhesive layers, eliminating the need for complex thread adjustments or alignment operations, thus simplifying the assembly process. The second lens tube can slide axially within the adjusting tube, achieving continuous fine adjustment through a slotted hole and fastening bolts. This ensures precise optimization of the beam magnification and collimation while allowing for rapid locking and repeated positioning. The optical axes of the first, second, and third lenses and the laser emitter are strictly aligned with the central axes of each tube, improving the optical consistency of the system. Attached Figure Description

[0017] Figure 1 This is a perspective view of the front end of a compact laser beam expander according to an embodiment of this application.

[0018] Figure 2 This is a rear-view perspective view of a compact laser beam expander according to an embodiment of this application.

[0019] Figure 3 This is a side sectional view of a compact laser beam expander according to an embodiment of this application.

[0020] Figure 4 This is a top sectional view of a compact laser beam expander according to an embodiment of this application.

[0021] Figure 5 This is a three-dimensional exploded view of the front end of a compact laser beam expander according to an embodiment of this application.

[0022] Figure 6 This is a three-dimensional exploded view of the rear view of a compact laser beam expander according to an embodiment of this application.

[0023] Reference numerals: 1. Base; 2. Integrated mounting tube; 201. Beam expander section; 202. Adjustment tube section; 203. Emitting tube section; 3. First lens tube; 301. First step section; 302. Second step section; 4. Second lens tube; 401. Third step section; 5. First lens; 6. Second lens; 7. Third lens; 8. Laser emitter; 9. Adhesive layer; 10. Positioning protrusion; 11. Fastening bolt; 12. Axial sleeve; 13. Flange; 14. Fixing plate; 15. Strip-shaped slot; 16. Mounting groove; 17. Dust cover; 18. Connecting lug; 19. Positioning groove. Detailed Implementation

[0024] To make the content of this application easier to understand, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to the accompanying drawings. Figure 1 In this context, the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. Furthermore, terms such as "first," "second," etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0025] like Figures 1-6As shown, a compact laser beam expander includes a base 1, an integrated mounting cylinder 2, a first lens barrel 3, a second lens barrel 4, a first lens 5, a second lens 6, a third lens 7, and a laser emitter 8. The integrated mounting cylinder 2 is fixedly mounted on the base 1. The integrated mounting cylinder 2 includes a beam expander section 201, an adjustment section 202, and an emitter section 203. The front end of the beam expander section 201 is open. The first lens barrel 3 is fixedly mounted inside the beam expander section 201 through the front opening. The rear end of the beam expander section 201 is fixedly connected to the front end of the adjustment section 202. A first step section 301 and a second step section 302 are sequentially formed along the axial direction on the inner sidewall of the first lens barrel 3. The diameter of the front opening of the first lens barrel 3 is... The diameter of the first step portion 301 is larger than the diameter of the second step portion 302, and the diameter of the second step portion 302 is larger than the diameter of the rear opening of the first lens barrel 3. The inner wall of the first step portion 301 and the outer wall of the first lens 5, as well as the inner wall of the second step portion 302 and the outer wall of the second lens 6, are fixedly connected by an adhesive layer 9. Both the first and second lenses are positive meniscus lenses, with their concave surfaces serving as light-incoming surfaces and their convex surfaces as light-exiting surfaces. The adhesive layer 9 is composed of an adhesive, including but not limited to any one or a combination of polyurethane adhesive, epoxy resin adhesive, and phenolic resin adhesive. The front end of the first lens barrel 3 is inserted into the beam expander portion 201. The front outer wall of the first lens barrel 3 is provided with a flange 13 at the front opening of the beam expander 201 and is fixedly connected by screws. The rear end of the first lens barrel 3 is inserted into the front end of the adjustment cylinder 202 and the side walls of the two are in contact. A fixing plate 14 is also fixed on the outer outer wall of the rear end of the first lens barrel 3. The outer outer wall of the fixing plate 14 is in contact with the inner side wall of the beam expander 201 and multiple connecting bolts are provided at equal intervals along its circumference and are fixedly connected to the beam expander 201 by threaded connection. In this design, the front end of the first lens barrel 3 is positioned inside the front opening of the beam expander 201 and the rear end is positioned inside the front end of the adjustment cylinder 202, and the flange 13 at the front end of the first lens barrel 3 is connected to the beam expander 201. The front end of the barrel 201 is fixed with screws, which enables the rapid positioning and disassembly of the first lens barrel 3. The rear end fixing plate 14 of the first lens barrel 3 is connected to the inner wall of the beam expander barrel 201 by multi-point connecting bolts, which makes the contact surface between the first lens barrel 3 and the integrated mounting barrel 2 larger and more robust, and can withstand higher torque and vibration, further improving the mechanical stability and impact resistance of the system. The first lens 5 and the second lens 6 are positioned sequentially by means of the first step 301 and the second step 302, respectively. The internal two-stage step structure ensures high coaxiality and accurate positioning of the lens and the lens barrel, without the need for subsequent fine adjustment. The adhesive layer 9 between the steps further eliminates micro gaps, ensuring rigid positioning and optical stability of the lens.

[0026] A second lens barrel 4 is slidably installed inside the adjusting cylinder 202. A third step 401 is formed on the inner side wall of the opening at one end of the second lens barrel 4. The inner side wall of the third step 401 is also fixedly connected to the outer side wall of the third lens 7 by an adhesive layer 9. The third lens is a biconcave lens. A strip-shaped slot 15 is formed through the side wall of the adjusting cylinder 202 along its axial direction. A fastening bolt 11 passes through the strip-shaped slot 15 and is threaded to the outer side wall of the second lens barrel 4. A mounting groove 16 is also formed at the outer edge of the opening of the strip-shaped slot 15. A dust cover 17 is embedded in the mounting groove 16. The dust cover 17 is used to cover the fastening bolt. 11 and strip-shaped slot 15; In this design, the adjusting cylinder 202 serves as the sliding channel for the second lens barrel 4, and the axial fine adjustment of the second lens 6 is achieved through the cooperation of the side wall strip-shaped slot 15 and the fastening bolt 11. After the fastening bolt 11 is positioned, no additional centering operation is required, and the repeatability is high. The third lens 7 is fixed to the third step 401 of the second lens barrel 4, ensuring high coaxiality and accurate position of the lens and the lens barrel. The strip-shaped slot combined with the dust cover 17 design allows for continuous adjustment to optimize the beam expansion magnification and divergence angle, while the dust cover 17 isolates impurities from entering, maintaining adjustment accuracy and long-term stability.

[0027] The rear end of the adjusting cylinder 202 is fixedly connected to the front end of the emitting cylinder 203. An axial sleeve 12 is fixedly installed inside the emitting cylinder 203 along its axial direction. The shape and size of the inner sidewall of the axial sleeve 12 are adapted to the shape and size of the outer sidewall of the laser emitter 8. The laser emitter 8 is installed inside the axial sleeve 12. Connecting ears 18 are fixedly provided on both the left and right sides of the rear end of the laser emitter 8. After the laser emitter 8 is installed inside the axial sleeve 12, the laser emitter 8 is fixedly connected to the rear end of the emitting cylinder 203 by screws passing through the connecting ears 18. This design ensures the axial positioning of the laser emitter 8. In addition, positioning grooves 19 are provided on the upper and lower outer sidewalls of the laser emitter 8 along its axial direction. Positioning protrusions 10 are fixedly provided on the upper and lower inner sidewalls of the axial sleeve 12 along its axial direction. The positioning grooves 19 are adapted to the positioning protrusions 10. After the laser emitter 8 is installed inside the axial sleeve 12, the positioning protrusions 10 are located in the positioning grooves 19. The inner wall of the axial sleeve 12 and the outer wall of the laser emitter 8 are geometrically matched and cooperate for upper and lower positioning. The protrusion 10 and the transmitter positioning groove 19 enable self-alignment installation, ensuring that the laser optical axis is coaxial with the central axis of the entire system without the need for external clamps. This results in a compact structure, quick assembly, and high positioning accuracy, achieving radial positioning and rapid clamping of the transmitter. The optical axes of the first lens 5, the second lens 6, the third lens 7, and the laser transmitter 8 coincide, as do the central axes of the beam expander 201, the adjusting cylinder 202, and the emitting cylinder 203. The central axis of the first lens barrel 3 aligns with the central axis of the beam expander 201. The optical axes of the second lens tube 4 and the adjustment tube 202 are coincident. The optical axes of the first lens 5, the second lens 6, the third lens 7 and the laser emitter 8 are coincident with the optical axes of the beam expander 201, the adjustment tube 202 and the emission tube 203. In this design, the optical axes of the beam expander 201, the adjustment tube 202 and the emission tube 203 are strictly coincident with the optical axes of each lens tube, lens and laser emitter 8, to ensure high collimation and low divergence angle when the beam is shaped and emitted.

[0028] In addition, the beam expander 201, the adjusting 202, the launching 203, and the axial sleeve 12 are integrally molded structures. The beam expander 201, the adjusting 202, the launching 203, and the axial sleeve 12 are integrated by injection molding or machining in one step, reducing the number of parts and ensuring the coaxiality of each component.

[0029] The above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features, without departing from the spirit and scope defined by the claims of this application.

Claims

1. A compact laser beam expander comprising a seat (1), an integrated mounting cylinder (2), a first lens cylinder (3), a second lens cylinder (4), a first lens (5), a second lens (6), a third lens (7) and a laser emitter (8), characterized in that, The seat body (1) is fixed with an integrated mounting cylinder (2), the front end of the integrated mounting cylinder (2) is fixedly provided with a first lens barrel (3), the middle part of the integrated mounting cylinder (2) is adjustably provided with a second lens barrel (4), the rear end of the integrated mounting cylinder (2) is fixedly provided with a laser emitter (8), the first lens barrel (3) is sequentially fixedly provided with a first lens (5) and a second lens (6) from front to back, the second lens barrel (4) is fixedly provided with a third lens (7), the optical axes of the first lens (5), the second lens (6), the third lens (7) and the laser emitter (8) coincide, and the first lens (5), the second lens (6) and the third lens (7) are respectively fixed in the first lens barrel (3) and the second lens barrel (4) through the adhesive layer (9).

2. A compact laser beam expander mirror according to claim 1, wherein, The integrated mounting cylinder (2) comprises a beam expansion cylinder (201), an adjusting cylinder (202) and an emission cylinder (203), the front end of the beam expansion cylinder (201) is provided as an opening, the first lens barrel (3) is fixedly installed in the beam expansion cylinder (201) through the opening at the front end of the beam expansion cylinder (201), the rear end of the beam expansion cylinder (201) is fixedly connected with the front end of the adjusting cylinder (202), the second lens barrel (4) is slidingly installed in the adjusting cylinder (202), the fastening bolt (11) is threadedly connected to the outer side wall of the second lens barrel (4), and the second lens barrel (4) can be fixedly connected with the adjusting cylinder (202) through the fastening bolt (11) after position adjustment, the rear end of the adjusting cylinder (202) is fixedly connected with the front end of the emission cylinder (203), the axial sleeve (12) is fixedly arranged in the emission cylinder (203) along the axial direction, the shape and size of the inner side wall of the axial sleeve (12) are matched with the shape and size of the outer side wall of the laser emitter (8), and the laser emitter (8) is fixedly installed in the axial sleeve (12).

3. A compact laser beam expander mirror according to claim 2, wherein, The central axes of the beam expansion cylinder (201), the adjusting cylinder (202) and the emission cylinder (203) coincide, the central axis of the first lens barrel (3) coincides with the central axis of the beam expansion cylinder (201), the central axis of the second lens barrel (4) coincides with the central axis of the adjusting cylinder (202), and the optical axes of the first lens (5), the second lens (6), the third lens (7) and the laser emitter (8) coincide with the central axes of the beam expansion cylinder (201), the adjusting cylinder (202) and the emission cylinder (203).

4. A compact laser beam expander mirror according to claim 3, wherein, The first mirror barrel (3) is provided with a first step portion (301) and a second step portion (302) on the inner side wall along the axial direction, the diameter of the front end opening of the first mirror barrel (3) is larger than the diameter of the first step portion (301), the diameter of the first step portion (301) is larger than the diameter of the second step portion (302), the diameter of the second step portion (302) is larger than the diameter of the rear end opening of the first mirror barrel (3), and the third step portion (401) is arranged on the inner side wall of the opening of the second mirror barrel (4), the inner side wall of the first step portion (301) and the outer side wall of the first lens (5), the inner side wall of the second step portion (302) and the outer side wall of the second lens (6), and the inner side wall of the third step portion (401) and the outer side wall of the third lens (7) are fixedly connected through the adhesive layer (9).

5. A compact laser beam expander mirror as claimed in claim 4, wherein, The front end of the first mirror barrel (3) is inserted into the inside of the beam expander barrel portion (201) and the side walls thereof are in contact, the flange (13) is arranged on the outer side wall of the front end of the first mirror barrel (3) and the front end opening of the beam expander barrel portion (201) and is fixedly connected through screws, the rear end of the first mirror barrel (3) is inserted into the inside of the front end of the adjusting barrel portion (202) and the side walls thereof are in contact, the fixing plate (14) is further fixedly arranged on the outer side wall of the rear end of the first mirror barrel (3), the outer side wall of the fixing plate (14) is in contact with the inner side wall of the beam expander barrel portion (201) and a plurality of connecting bolts are equidistantly arranged on the outer side wall of the fixing plate (14) along the circumferential direction and are fixedly connected with the beam expander barrel portion (201) through threads.

6. A compact laser beam expander mirror as claimed in claim 4, wherein, The strip-shaped slot hole (15) is arranged on the side wall of the adjusting barrel portion (202) along the axial direction, the fastening bolt (11) is threadedly connected with the outer side wall of the second mirror barrel (4) through the strip-shaped slot hole (15), the mounting groove (16) is further arranged on the outer side opening edge of the strip-shaped slot hole (15), the dust cover (17) is embedded in the mounting groove (16), and the dust cover (17) is used for covering the fastening bolt (11) and the strip-shaped slot hole (15).

7. A compact laser beam expander mirror as claimed in claim 3, wherein, The connecting ears (18) are fixedly arranged on the left and right sides of the rear end of the laser emitter (8), the laser emitter (8) is fixedly connected with the rear end of the emitting barrel portion (203) through screws passing through the connecting ears (18) after the laser emitter (8) is arranged in the axial sleeve (12).

8. A compact laser beam expander mirror as claimed in claim 3, wherein, The positioning grooves (19) are arranged on the upper and lower outer side walls of the laser emitter (8) along the axial direction, the positioning protrusions (10) are fixedly arranged on the upper and lower inner side walls of the axial sleeve (12) along the axial direction, the positioning grooves (19) are matched with the positioning protrusions (10), and the positioning protrusions (10) are arranged in the positioning grooves (19) after the laser emitter (8) is arranged in the axial sleeve (12).

9. A compact laser beam expander mirror as claimed in claim 2, wherein, The expansion barrel part (201), the adjusting barrel part (202) and the emission barrel part (203) and the axial sleeve (12) are integrally formed structures.

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