阅读说明：本技术 变倍扩束镜光束指向性的调试方法 (Method for debugging beam directivity of zoom beam expander ) 是由 向南 陈国栋 梁宗森 吕洪杰 翟学涛 杨朝辉 于 2021-08-18 设计创作，主要内容包括：本发明提供的变倍扩束镜光束指向性的调试方法,方法包括：对调节架上的变倍扩束镜进行准直调节,其中,变倍扩束镜包括沿入射光传输方向设置的第一透镜、第二透镜、第三透镜和第四透镜；沿变倍扩束镜的光路传输方向设置光斑分析仪,将光斑分析仪中显示的光斑能量中心坐标值的初始值记为第一坐标值；改变变倍扩束镜的倍率,获得光斑能量中心的第二坐标值；第一坐标值与第二坐标值之间的距离值为偏差值,距离值在偏差值的预设范围外时,通过调节架持续调节第四透镜的位置,获得第三坐标值,直至第三坐标值与第一坐标值的距离值在偏差值的预设范围内时,指向调试完成。本发明的变倍扩束镜光束指向性的调试方法减小了扩束镜的指向性偏差。(The invention provides a method for debugging the beam directivity of a zoom beam expander, which comprises the following steps: collimating and adjusting a zoom beam expander on the adjusting frame, wherein the zoom beam expander comprises a first lens, a second lens, a third lens and a fourth lens which are arranged along the transmission direction of incident light; setting a light spot analyzer along the light path transmission direction of the zoom beam expander, and recording an initial value of a light spot energy center coordinate value displayed in the light spot analyzer as a first coordinate value; changing the multiplying power of the zoom beam expander to obtain a second coordinate value of the energy center of the light spot; and when the distance value is out of the preset range of the deviation value, the position of the fourth lens is continuously adjusted through the adjusting frame to obtain a third coordinate value, and the pointing debugging is completed until the distance value between the third coordinate value and the first coordinate value is within the preset range of the deviation value. The debugging method for the beam directivity of the variable-magnification beam expander reduces the directivity deviation of the beam expander.)

1. The method for debugging the beam directivity of the zoom beam expander is characterized by comprising the following steps of:

the method comprises the following steps of carrying out collimation adjustment on a zoom beam expander on an adjusting frame, wherein the zoom beam expander comprises a first lens, a second lens, a third lens and a fourth lens which are arranged along the transmission direction of incident light, the first lens is an input lens, the fourth lens is an output lens, and the second lens and the third lens are movably arranged along the transmission direction of a light path;

setting a light spot analyzer along the light path transmission direction of the zoom beam expander, wherein the light spot analyzer is used for displaying a light spot energy central coordinate value, a light beam is projected on the light spot analyzer through the zoom beam expander, and an initial value of the light spot energy central coordinate value displayed in the light spot analyzer is recorded as a first coordinate value;

changing the distance between the second lens and the third lens to change the multiplying power of the zoom beam expander to obtain a second coordinate value of the energy center of the light spot;

and when the distance value is out of the preset range of the deviation value, continuously adjusting the position of the fourth lens through the adjusting frame to obtain a third coordinate value, and when the distance value between the third coordinate value and the first coordinate value is within the preset range of the deviation value, finishing the pointing debugging.

2. The debugging method according to claim 1, wherein after the directed debugging is completed, the method further comprises:

moving the second lens and the third lens for one time or multiple times to change the multiplying power of the variable-magnification beam expanding lens;

checking whether a distance value between a fourth coordinate value of the light spot energy center obtained by the light spot analyzer and the first coordinate value is within a preset range of the deviation value;

and if the distance value between the fourth coordinate value and the first coordinate value is within the preset range of the deviation value, finishing the beam pointing debugging of the zoom beam expander.

3. The method as claimed in claim 2, wherein if the distance between the fourth coordinate and the first coordinate is not within the predetermined range of the deviation, the adjusting frame continuously adjusts the position of the fourth lens to obtain a fifth coordinate, and the debugging of the pointing direction is completed until the distance between the fifth coordinate and the first coordinate is within the predetermined range of the deviation.

4. The method for adjusting beam directivity of a zoom expander according to claim 1, wherein the first lens and the fourth lens are both biconvex positive lenses; the second lens and the third lens are both double concave negative lenses.

5. The method for adjusting the beam directivity of a zoom beam expander according to claim 1, wherein the predetermined range of the deviation value is 0-100 um.

6. The method for adjusting beam directivity of a variable-power beam expander according to claim 1, wherein when the spot energy center is at the first coordinate value, the magnification of the variable-power beam expander is a first magnification; when the spot energy center is at the second coordinate value, the multiplying power of the variable-magnification beam expander is a second multiplying power; the difference range of the second multiplying power and the first multiplying power is 0.1-3.

7. The method for adjusting the beam directivity of the variable-power beam expander according to claim 1, wherein the adjusting frame comprises a first adjusting mechanism, a second adjusting mechanism, an adjusting plate and a fixing member, and the variable-power beam expander is mounted on the adjusting plate; an XYZ-axis coordinate system is arranged in the space where the adjusting plate is located, and the first adjusting mechanism is mounted on the fixing piece, is located on one side of an XZ plane of the adjusting plate and drives the adjusting plate to rotate around a Y-axis; the second adjusting mechanism is installed on the fixing piece and arranged at two ends of the adjusting plate to drive the adjusting plate to move along the Z-axis direction.

8. The method for adjusting the beam directivity of a zoom beam expander according to claim 7, wherein the fixing member includes a bottom plate and a side plate, the side plate is mounted on the bottom plate, and the first adjusting mechanism is connected to the adjusting plate through the side plate; the second adjusting mechanism is installed on the bottom plate.

9. The method for adjusting the beam directivity of a zoom beam expander according to claim 8, wherein the first adjusting mechanism includes two first adjusting screws, a threaded hole is formed in a side of the adjusting plate, and the two first adjusting screws penetrate through the side plate and are connected with the threaded hole; the second adjusting mechanism comprises a plurality of second adjusting screws, the second adjusting screws are arranged at two ends of the bottom plate respectively, and one end of each second adjusting screw penetrates through the adjusting plate.

10. The method for adjusting the beam directivity of a zoom beam expander according to claim 8, wherein the adjusting bracket further includes a first reset member and a second reset member, and a side edge of the adjusting plate is connected to the side plate through the first reset member; the second resets the piece setting and is in the regulating plate both ends, the regulating plate passes through the second resets the piece with the bottom plate is connected.

Technical Field

The invention relates to the technical field of beam expander debugging, in particular to a method for debugging the beam directivity of a variable-power beam expander.

Background

In the laser processing equipment adopting the optical path structure, the variable-magnification beam expander is often used, and when the variable-magnification beam expander is used under the ideal condition, the pointing direction of a light beam cannot be changed after the light beam passes through the lens, and the pointing direction of the light beam cannot be changed in the zooming process. However, in the actual use process, the beam expander may be pointed at a deviation due to an error in the machining process of a machine or a component or an error in the installation process of the lens. The pointing quality of the variable-magnification beam expanding lens directly determines the quality of an optical path, so that the pointing debugging of the variable-magnification beam expanding lens is very important.

The present beam expander mainly realizes adjusting the directional deviation of beam expander through the mode of beam expander collimation, but beam expander collimation is adjusted the axiality of focusing, so can not adjust the energy distribution of focusing, and it is therefore visible, current directive deviation to the beam expander regulation effect is relatively poor, therefore present beam expander directive adjustment mode is waiting to improve and expand.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: aiming at the problem that the existing debugging method of the beam directivity of the zoom beam expander is poor, the debugging method of the beam directivity of the zoom beam expander is provided.

The invention provides a method for debugging the beam directivity of a zoom beam expander, which comprises the following steps:

the method comprises the following steps of carrying out collimation adjustment on a zoom beam expander on an adjusting frame, wherein the zoom beam expander comprises a first lens, a second lens, a third lens and a fourth lens which are arranged along the transmission direction of incident light, the first lens is an input lens, the fourth lens is an output lens, and the second lens and the third lens are movably arranged along the transmission direction of a light path;

setting a light spot analyzer along the light path transmission direction of the zoom beam expander, wherein the light spot analyzer is used for displaying a light spot energy central coordinate value, a light beam is projected on the light spot analyzer through the zoom beam expander, and an initial value of the light spot energy central coordinate value displayed in the light spot analyzer is recorded as a first coordinate value;

changing the distance between the second lens and the third lens to change the multiplying power of the zoom beam expander to obtain a second coordinate value of the energy center of the light spot;

and when the distance value is out of the preset range of the deviation value, the position of the fourth lens is continuously adjusted through the adjusting frame to obtain a third coordinate value, and the pointing debugging is completed until the distance value between the third coordinate value and the first coordinate value is within the preset range of the deviation value.

Optionally, after the pointing debugging is completed, the method further includes:

moving the second lens and the third lens for one time or multiple times to change the multiplying power of the variable-magnification beam expanding lens;

and checking whether a distance value between a fourth coordinate value and the first coordinate value of the light spot energy center obtained by the light spot analyzer is within a preset range of the deviation value, and if the distance value between the fourth coordinate value and the first coordinate value is within the preset range of the deviation value, completing the light beam directivity debugging of the zoom beam expander.

Optionally, if the distance value between the fourth coordinate value and the first coordinate value is not within the preset range of the offset value, the position of the fourth lens is continuously adjusted by the adjusting frame to obtain a fifth coordinate value, and the pointing debugging is completed until the distance value between the fifth coordinate value and the first coordinate value is within the preset range of the offset value.

Optionally, the first lens and the fourth lens are each a biconvex positive lens; the second lens and the third lens are both biconcave negative lenses.

Optionally, the preset value of the deviation value ranges from 0um to 100 um.

Optionally, when the spot energy center is at the first coordinate value, the magnification of the variable-magnification beam expander is a first magnification; when the spot energy center is at the second coordinate value, the multiplying power of the variable-magnification beam expander is a second multiplying power; the difference range of the second multiplying power and the first multiplying power is 0.1-3.

Optionally, the adjusting frame includes a first adjusting mechanism, a second adjusting mechanism, an adjusting plate and a fixing member, and the variable-magnification beam expander is mounted on the adjusting plate; an XYZ-axis coordinate system is arranged in the space where the adjusting plate is located, and the first adjusting mechanism is mounted on the fixing piece, is located on one side of an XZ plane of the adjusting plate and drives the adjusting plate to rotate around a Y-axis; the second adjusting mechanism is installed on the fixing piece and arranged at two ends of the adjusting plate to drive the adjusting plate to move along the Z-axis direction.

Optionally, the fixing member includes a bottom plate and a side plate, the side plate is mounted on the bottom plate, and the first adjusting mechanism penetrates through the side plate and is connected with the adjusting plate; the second adjusting mechanism is installed on the bottom plate.

Optionally, the first adjusting mechanism includes two first adjusting screws, a threaded hole is formed in a side edge of the adjusting plate, and the two first adjusting screws penetrate through the side plate and are connected with the threaded hole; the second adjusting mechanism comprises a plurality of second adjusting screws, the second adjusting screws are arranged at two ends of the bottom plate respectively, and one end of each second adjusting screw penetrates through the adjusting plate.

Optionally, the adjusting bracket further comprises a first resetting piece and a second resetting piece, and the side edge of the adjusting plate is connected with the side plate through the first resetting piece; the second resets the piece setting and is in the regulating plate both ends, the regulating plate passes through the second resets the piece with the bottom plate is connected.

Based on the prior art, after the variable-power beam expander is subjected to collimation adjustment, only the coaxiality of the light beam is adjusted, and the energy distribution of the light beam is not adjusted, so that the energy distribution of the light beam is not concentrated through the variable-power beam expander. In the invention, a light spot analyzer is arranged to observe the coordinate change of a light spot energy center, change the multiplying power of a zoom beam expander, fix the position of an input mirror, and adjust the position of an output mirror, so that the coordinate of the light spot energy center is close to a first coordinate value, the distance value of the coordinate values before and after zooming is reduced, the distance value is in a preset range of a deviation value, the pointing debugging is completed, and the light beam passing through the zoom beam expander is high in coaxiality and concentrated in energy distribution. After the variable-power beam expander is used for collimation adjustment, the directivity of the variable-power beam expander is adjusted, the adjustment precision of the variable-power beam expander is improved, the energy of the light beam passing through the variable-power beam expander is concentrated, and the processing efficiency is further improved.

Drawings

Fig. 1 is a schematic structural diagram of a variable-power beam expander according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a light spot when a light spot center is a first coordinate value in the method for adjusting the beam directivity of the zoom beam expander according to the embodiment of the present invention;

fig. 3 is a schematic diagram of a light spot when a light spot center is a second coordinate value in the method for adjusting the beam directivity of the zoom beam expander according to the embodiment of the present invention;

fig. 4 is a schematic diagram of a light spot when a light spot center is a third coordinate value in the method for adjusting the beam directivity of the zoom beam expander according to the embodiment of the present invention;

fig. 5 is a schematic diagram of a light spot when a light spot center is a fourth coordinate value in the method for adjusting the beam directivity of the zoom beam expander according to the embodiment of the present invention;

fig. 6 is a schematic diagram of a light spot when a light spot amount center is a fifth coordinate value in the method for adjusting the beam directivity of the zoom beam expander according to the embodiment of the present invention;

FIG. 7 is a diagram of a beam expander entrance after collimation adjustment of a zoom beam expander provided in a pair of scales according to the present invention;

FIG. 8 is a diagram of the exit of a beam expander after collimation adjustment of a zoom expander provided in a pair of scales according to the present invention;

FIG. 9 is a schematic view of a light spot at 1.1 magnification in a 1.2m light path after collimation adjustment of a zoom beam expander provided in a pair of ratios according to the present invention;

FIG. 10 is a schematic view of a light spot at 1.5 magnification in a 1.2m light path after collimation adjustment of a pair of proportionally provided variable-magnification beam expanders;

fig. 11 is a schematic diagram of an adjusting bracket used in the method for adjusting the beam directivity of the zoom beam expander according to an embodiment of the present invention;

fig. 12 is a schematic view of an adjusting bracket in the method for adjusting the beam directivity of the zoom beam expander according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In order to explain the technical means of the present invention, the following description will be given by way of specific examples.

As shown in fig. 1, an embodiment of the present invention provides a method for adjusting beam directivity of a variable-power beam expander, including the following steps:

the method comprises the following steps: and carrying out collimation adjustment on a zoom beam expander 20 on the adjusting frame 10, wherein the zoom beam expander 20 comprises a first lens 21, a second lens 22, a third lens 23 and a fourth lens 24 which are arranged along the transmission direction of incident light, the first lens 21 is an input lens, the fourth lens 24 is an output lens, and the second lens 22 and the third lens 23 are movably arranged along the transmission direction of an optical path.

Step two: and a light spot analyzer is arranged along the light path transmission direction of the zoom beam expander 20 and is used for displaying the coordinate value of the energy center of the light spot, the light beam is projected on the light spot analyzer through the zoom beam expander 20, and the initial value of the coordinate value of the energy center of the light spot displayed in the light spot analyzer is recorded as a first coordinate value. The position of the spot analyzer remains unchanged.

Step three: and changing the distance between the second lens 22 and the third lens 23 to change the multiplying power of the zoom beam expander 20 to obtain a second coordinate value of the energy center of the light spot.

Step four: the distance value between the first coordinate value and the second coordinate value is a deviation value, which is a pointing deviation after the magnification of the variable-magnification beam expander 20 is changed, and the smaller the distance value is, the smaller the pointing change of the variable-magnification beam expander 20 is, and the larger the distance value is, the larger the pointing change of the variable-magnification beam expander 20 is. And when the distance value is out of the preset range of the deviation value, the position of the fourth lens 24 is adjusted by the continuous adjusting frame 10 to obtain a third coordinate value, and the pointing debugging is completed until the distance value between the third coordinate value and the first coordinate value is within the preset range. Specifically, the position of the fourth lens is adjusted by a three-dimensional adjusting bracket or a four-dimensional adjusting bracket.

In the present embodiment, based on the prior art, after the variable-power beam expander 20 is adjusted by collimation, only the coaxiality of the light beam is adjusted, and the energy distribution of the light beam is not adjusted, so that the energy distribution of the light beam is not concentrated by the variable-power beam expander 20. The coordinate change of the light spot energy center is observed by setting a light spot analyzer, the multiplying power of the zoom beam expander 20 is changed, the position of the input mirror is fixed, the position of the output mirror is adjusted, the coordinate of the light spot energy center is close to a first coordinate value, the distance value of the coordinate values before and after zooming is reduced, the distance value is in the preset range of the deviation value, and the pointing debugging is completed. So that the coaxiality of the light beams passing through the zoom beam expander 20 is high and the energy distribution is concentrated. After the collimation adjustment is performed by the variable-power beam expander 20, the directivity of the variable-power beam expander 20 is adjusted, so that the adjustment accuracy of the variable-power beam expander 20 is improved, the energy of the light beam passing through the variable-power beam expander 20 is concentrated, and the processing efficiency is further improved.

In some embodiments of the invention, after the pointing to debug is completed, the method further comprises: step five: the second lens 22 and the third lens 23 are moved once or more times to change the magnification of the variable power beam expander 20. And checking whether the distance value between the fourth coordinate value and the first coordinate value of the light spot energy center obtained by the light spot analyzer is within the preset range of the deviation value. And if the distance value between the fourth coordinate value and the first coordinate value is within the preset range of the deviation value, debugging the beam directivity of the zoom beam expander is completed.

In some embodiments of the present invention, if the distance between the fourth coordinate value and the first coordinate value is not within the preset range of the offset value, the adjusting frame continuously adjusts the position of the fourth lens to obtain the fifth coordinate value, until the distance between the fifth coordinate value and the first coordinate value is within the preset range of the offset value, the pointing debugging is completed. And step five is repeated, and the result of the directivity adjustment is checked by changing the multiplying power of the beam expander, so that the accuracy of the directivity adjustment is ensured.

As shown in fig. 1, in some embodiments of the present invention, the first lens 21 and the fourth lens 24 are each a double convex positive lens. The second lens 22 and the third lens 23 are each a biconcave negative lens.

In some embodiments of the present invention, the deviation value is set to a predetermined value ranging from 0 to 100 um.

In some embodiments of the present invention, when the energy center of the light spot is at the first coordinate value, the magnification of the variable magnification beam expander 20 is the first magnification. When the spot energy center is at the second coordinate value, the magnification of the variable magnification beam expander 20 is the second magnification. The difference range of the second multiplying power and the first multiplying power is 0.1-3. The larger the difference between the second magnification and the first magnification, the larger the directivity deviation of the variable-magnification beam expander 20, and the smaller the difference between the second magnification and the first magnification, the more the directivity of the variable-magnification beam expander 20 is adjusted.

As shown in fig. 11 and 12, in some embodiments of the present invention, the adjusting bracket 10 includes a first adjusting mechanism 11, a second adjusting mechanism 12, an adjusting plate 13, and a fixing member 14, and the variable magnification beam expanding mirror 20 is mounted on the adjusting plate 13. An XYZ-axis coordinate system is set in the space where the adjusting plate 13 is located, and the first adjusting mechanism 11 is mounted on the fixing member 14 and located on one side of an XZ plane of the adjusting plate 13, and drives the adjusting plate 13 to rotate around a Y-axis. The second adjusting mechanism 12 is installed on the fixing member 14, and is disposed at two ends of the adjusting plate 13 to drive the adjusting plate 13 to move along the Z-axis direction. Through setting up first adjustment mechanism 11 and second adjustment mechanism 12, be convenient for adjust the output end position of becoming doubly beam expander 20, simultaneously, use this alignment jig 10 to accomplish in proper order and adjust becoming doubly beam expander 20's collimation and directive property, simple structure, it is efficient, it is convenient to adjust the maintenance.

As shown in fig. 11 and 12, in some embodiments of the present invention, the fixing member 14 includes a bottom plate 141 and a side plate 142, the side plate 142 is mounted on the bottom plate 141, and the first adjusting mechanism 11 is connected to the adjusting plate 13 through the side plate 142. The second adjustment mechanism 12 is mounted on the base plate 141.

As shown in fig. 11 and 12, in some embodiments of the present invention, the first adjusting mechanism 11 includes two first adjusting screws 111, a side of the adjusting plate 13 is provided with a screw hole, and the two first adjusting screws 111 are connected to the screw hole through the side plate 142. The angle of the adjustment plate 13 is changed by changing the amount of the first adjustment screw 111 screwed into the screw hole.

As shown in fig. 11 and 12, in some embodiments of the present invention, the second adjusting mechanism 12 includes a plurality of second adjusting screws 121, the plurality of second adjusting screws 121 are respectively installed at both ends of the base plate 141, and one end of the second adjusting screw 121 passes through the adjusting plate 13. Specifically, one second adjusting screw 121 is installed at one end of the adjusting plate 13, two second adjusting screws 121 are installed at the other end of the adjusting plate 13, and the second adjusting screws 121 at the two ends form a triangle, so that the adjusting plate 13 is convenient to stabilize.

As shown in fig. 11 and 12, in some embodiments of the present invention, the adjusting bracket 10 further includes a first restoring member 15 and a second restoring member 16, and a side edge of the adjusting plate 13 is connected to the side plate 142 through the first restoring member 15. The second restoring member 16 is disposed at both ends of the adjusting plate 13, and the adjusting plate 13 is connected to the base plate 141 through the second restoring member 16. Specifically, first piece 15 and the second piece 16 that resets are the spring that resets, and the position that resets through first piece 15 and the second piece 16 that resets keeps the regulating plate 13 resets with the realization, simple structure, efficient, it is convenient to adjust the maintenance.

The present invention will be further illustrated by the following examples.

Example 1

In this embodiment, the zoom beam expander 20 is mounted on the adjusting bracket 10, and placed in the optical path to perform collimation adjustment on the beam expander, a light spot analyzer is disposed in the rear optical path of the zoom beam expander 20, the distance between the light spot analyzer and the zoom beam expander 20 is 1.2m, at this time, the magnification of the zoom beam expander 20 is 1.0 time, the light spot energy center coordinate value is displayed on the light spot analyzer, and the first coordinate value is recorded, as shown in fig. 2.

The second lens 22 and the third lens 23 are moved to enlarge the magnification of the variable magnification beam expander 20 to 1.6 times, and a second coordinate value of the spot energy center is obtained, as shown in fig. 3.

The distance value between the first coordinate value and the second coordinate value is an offset value, the distance value is outside a preset range, the position of the fourth lens 24, namely the output mirror, is adjusted by the adjusting frame 10, so that the energy center of the light spot approaches the first coordinate value, a third coordinate value is obtained, and when the distance value between the third coordinate value and the first coordinate value is within the preset range, the pointing debugging is completed, as shown in fig. 4.

The second lens 22 and the third lens 23 are moved to enlarge the magnification of the variable magnification beam expander 20 to 2 times, and a fourth coordinate value of the spot energy center is obtained, as shown in fig. 5.

The second lens 22 and the third lens 23 are moved to enlarge the magnification of the variable magnification beam expander 20 to 3 times, and a fifth coordinate value of the spot energy center is obtained, as shown in fig. 6.

And the fourth coordinate value and the distance value between the fifth coordinate value and the first coordinate value of the light spot energy center obtained by the inspected light spot analyzer are both in a preset range.

Comparative example 1

In this embodiment, the variable-power beam expander 20 is mounted on the adjusting frame 10, placed in the optical path, and the beam expander is collimated by the diaphragm, and the spot patterns of the entrance and the exit of the variable-power beam expander 20 at 1.0 magnification after the collimation adjustment are recorded, as shown in fig. 7 and 8.

The distance between the spot analyzer and the zoom beam expander 20 is increased to 1.2m, and the magnification of the zoom beam expander 20 is increased to 1.1, so that a spot diagram as shown in fig. 9 is obtained.

Then, the magnification of the variable magnification beam expander 20 is increased to 1.5 magnifications, and a flare map as shown in fig. 10 is obtained.

As can be seen from the test results of comparative example 1 in fig. 7-10, after the collimation adjustment, the optical path is coaxial, but after the optical path distance and the magnification of the variable-magnification beam expander 20 are changed, the directivity of the variable-magnification beam expander 20 has an obvious deviation value, the variable-magnification beam expander 20 performs pinhole diffraction through the diaphragm to adjust the collimation of the beam expander, and after the optical path is lengthened, the pinhole diffraction effect is deteriorated, and the directivity deviation of the variable-magnification beam expander 20 cannot be adjusted. As can be seen from the test results of embodiment 1, the directivity of the variable-power beam expander 20 can be adjusted by the method for adjusting the beam directivity of the variable-power beam expander according to the present invention, and the adjustment accuracy is ensured by the second verification.

The above examples are only for illustrating the technical solutions of the present invention, and are not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: modifications of the technical solutions described in the embodiments or equivalent replacements of some technical features may still be made. Such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.