Patent Publication Number: US-2023136630-A1

Title: Optical Module and Medical Laser Device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the priority of the Chinese patent application filed with the Chinese Patent Office on Jul. 31, 2020, with the application number CN202010757215.3, titled as “Optical Module and Medical Laser Device”, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present application relates to the technical field of applying light spots, in particular, to an optical module and a medical laser device. 
     BACKGROUND ART 
     In the application of a laser spot, it is necessary to convert the original Gaussian distribution emitted by the semiconductor laser into a flat-top distribution. Currently, a method is commonly used, wherein plural lens components are used, so that the overall volume of the system is larger. Moreover, in order to obtain a large-area point/line spot, the existing dot matrix technology needs to use a single-point scanning method, which is inefficient. 
     Although the array lens has the effect of cutting light into points/lines, in the application of laser medical treatment, the direct laser distribution is Gaussian distribution, and the axial size is small, and it cannot be directly converted by the lens array. 
     SUMMARY 
     The purpose of the present application is to provide an optical module and a medical laser device, which can realize the conversion of the original Gaussian distribution of the laser beam into a flat-top distribution, and the optical module is small in volume. 
     Embodiments of the present application are implemented as follows. 
     An aspect of the embodiments of the present application provides an optical module, which comprises a first lens, a second lens and an array lens arranged in sequence along a main optical axis, wherein the first lens shapes a beam along a first direction of the main optical axis, the second lens shapes the beam along a second direction of the main optical axis, the array lens has an array arranged along the second direction of the main optical axis, and a laser beam enters the second lens after passing through the first lens, the second lens diffuses the laser beam along the second direction and converts the laser beam from a Gaussian distribution to a flat-top distribution in the second direction, and then the laser beam exits through the array lens, wherein the first direction and the second direction are perpendicular to each other. 
     Optionally, the first lens is an ellipsoid lens, and the second lens is a hyperboloid lens. 
     Optionally, it further comprises a third lens located between the second lens and the array lens, wherein the third lens shapes a beam along a second direction of the main optical axis. 
     Optionally, the array lens comprises a plurality of first arc surfaces or a sawtooth surface continuously formed along the second direction, and the first arc surfaces or the sawtooth surface are located on an incident surface or an exiting surface of the array lens. 
     Optionally, the incident surface of the array lens is a flat surface, a convex surface or a concave surface, and the exiting surface of the array lens is formed of a plurality of the first arc surfaces or the sawtooth surface; or, the incident surface of the array lens is formed of a plurality of the first arc surfaces or a sawtooth surface, and the exiting surface of the array lens is a flat surface, a convex surface or a concave surface. 
     Optionally, the array lens further comprises a plurality of second arc surfaces or a sawtooth surface arranged along the first direction, and the second arc surfaces or the sawtooth surface are located on an incident surface or the exiting surface of the array lens. 
     Optionally, the incident surface or the exiting surface of the array lens comprises a plurality of first arc surfaces continuously formed along the second direction, and the incident surface or the exiting surface of the array lens further comprises a plurality of second arc surfaces continuously arranged along the first direction on the basis of the plurality of first arc surfaces; or the incident surface of the array lens is a sawtooth surface arranged along the first direction, and the exiting surface of the array lens is formed of a plurality of the first arc surfaces arranged along the second direction; or the incident surface of the array lens is formed of a plurality of the first arc surfaces arranged along the second direction, and the exiting surface of the array lens is a sawtooth surface arranged along the first direction; or the incident surface of the array lens is a sawtooth surface, and the exiting surface of the array lens is a sawtooth surface. 
     Optionally, the array lens comprises a first array lens and a second array lens, and the first arc surfaces or the sawtooth surface are located on an incident surface or an exiting surface of the first array lens, and/or the incident surface or the exiting surface of the second array lens. 
     Optionally, the array lens is an array reflecting mirror, and a plurality of first arc surfaces or sawtooth disposed along the second direction are continuously formed on the reflecting surface of the array reflecting mirror. 
     Optionally, the array lens can reciprocate along a sawtooth arrangement direction, or rotate along a main optical axis direction. 
     Optionally, tooth surfaces of the sawtooth have curvature. 
     Optionally, the first lens is movable along a main optical axis direction to change a light output range of the exiting surface of the array lens. 
     Optionally, a reflecting mirror is further provided between the second lens and the third lens. 
     Optionally, the reflecting mirror is rotatable along the main optical axis, and a rotation angle of the reflecting mirror is 0°-90°, so as to scan a light spot within the rotation angle. 
     Another aspect of the embodiments of the present application provides a medical laser device, comprising a casing which is therein provided with the laser and the optical module mentioned above, that is arranged in an exiting direction of the laser. 
     Optionally, the casing comprises a handle and a lens barrel, the laser is arranged in the handle, the optical module is arranged in the lens barrel, the lens barrel and the handle are detachably connected with each other; and the lens barrel comprises a replaceable head, the array lens is located in the replaceable head, and the replaceable head and the lens barrel are detachably connected. 
     Optionally, it further comprises a first motor and/or a second motor, wherein the first motor and the second motor are respectively connected to the first lens and the array lens. 
     The beneficial effects of the embodiments of the present application comprise the follows. 
     The optical module is provided by the embodiments of the present application, wherein a first lens, a second lens and an array lens are arranged in sequence along the main optical axis. The first lens compresses, converges and collimates the light beam emitted from the light source. The laser beam emitted from the light source is converted from Gaussian light to flat-top light through the second lens. The exiting surface of the array lens is configured to emit light and cut the light spot. The first lens shapes the light beam along the first direction of the main optical axis, and the second lens shapes the light beam along the second direction of the main optical axis. The array of the array lens is arranged along the second direction of the main optical axis. The first lens, the second lens and the array lens, which are combined and matched, are configured so that the laser beam enters the second lens after passing through the first lens. The second lens expands the laser beam, converts the Gaussian distribution of the laser beam into a flat-top distribution, and then it is emitted through the array lens. By arranging three optical elements, the laser beam can be converted from the original Gaussian distribution to the flat-top distribution, making the optical module small in size. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to illustrate the technical solutions of the embodiments of the present application more clearly, the drawings needed to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore it should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained according to these drawings without any creative efforts. 
         FIG.  1    is the first structural schematic diagram of a slow axis of an optical module provided by an embodiment of the present application; 
         FIG.  2    is the first optical path diagram of a slow axis of an optical module provided by an embodiment of the present application; 
         FIG.  3    is a structural schematic diagram of a fast axis of an optical module provided by an embodiment of the present application; 
         FIG.  4    is the first shape diagram of the slow axis output light spot of the optical module provided by the embodiment of the present application; 
         FIG.  5    is the second structural schematic diagram of the slow axis of the optical module provided by the embodiment of the present application; 
         FIG.  6    is the second shape diagram of the slow axis output light spot of the optical module provided by the embodiment of the present application; 
         FIG.  7    is the third shape diagram of the slow axis output light spot of the optical module provided by the embodiment of the present application; 
         FIG.  8    is the third structural schematic diagram of the slow axis of the optical module provided by the embodiment of the present application; 
         FIG.  9    is the second optical path diagram of the slow axis of the optical module provided by the embodiment of the present application; 
         FIG.  10    is the fourth shape diagram of the slow axis output light spot of the optical module provided by the embodiment of the present application; 
         FIG.  11    is the fifth shape diagram of the slow axis output light spot of the optical module provided by the embodiment of the present application; 
         FIG.  12    is the sixth shape diagram of the slow axis output light spot of the optical module provided by the embodiment of the present application; 
         FIG.  13    is the seventh shape diagram of the slow axis output light spot of the optical module provided by the embodiment of the present application; 
         FIG.  14    is a structural schematic diagram of an array lens of an optical module provided by an embodiment of the present application; 
         FIG.  15    is an optical path diagram of an array lens of an optical module provided by an embodiment of the present application; 
         FIG.  16    is the fourth structural schematic diagram of the slow axis of the optical module provided by the embodiment of the present application; 
         FIG.  17    is the fifth structural schematic diagram of the slow axis of the optical module provided by the embodiment of the present application; 
         FIG.  18    is the second structural schematic diagram of the fast axis of the optical module provided by the embodiment of the present application; 
         FIG.  19    is the sixth structural schematic diagram of the slow axis of the optical module provided by the embodiment of the present application; 
         FIG.  20    is the first structural schematic diagram of a medical laser device provided by an embodiment of the present application; 
         FIG.  21    is the second structural schematic diagram of a medical laser device provided by an embodiment of the present application; and 
         FIG.  22    is a defocus light path diagram of a slow axis of an optical module provided by an embodiment of the present application. 
     
    
    
     REFERENCE NUMBERS 
       100 —first lens;  201 —second lens;  202 —third lens;  300 —array lens;  400 —reflecting mirror;  501 —laser;  502 —heat sink;  503 —handle;  504 —spacer;  505 A—first motor;  505 B—second motor;  505 C—third motor;  506 —lens barrel;  5061 —replaceable head. 
     DETAILED DESCRIPTION 
     In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of embodiments of the present application. Generally, the components of the embodiments of the present application described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. 
     Thus, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application as claimed, but is merely representative of selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application. 
     It should be noted that similar reference numbers and letters refer to similar items in the following drawings, and thus once an item is defined in one drawing, it is not required to further define and explain it in subsequent drawings. 
     Referring to  FIG.  1   , this embodiment provides an optical module, which comprises a first lens  100 , a second lens  201 , a third lens  202  and an array lens  300  arranged in sequence along the main optical axis, wherein the first lens  100  shapes the light beam along the first direction of the main optical axis, the second lens  201  shapes the light beam along the second direction of the main optical axis, and the third lens  202  shapes the light beam along the second direction of the main optical axis. The array of the array lens  300  is arranged along the second direction of the main optical axis. The laser beam enters the second lens  201  after passing through the first lens  100 . The second lens  201  diffuses the laser beam, and converts the Gaussian distribution of the laser beam into a flat-top distribution, and then it is exited through the array lens  300 . 
     The laser light emitted from the light source passes through the first lens  100 , the second lens  201 , the third lens  202  and the array lens  300  in sequence. The light source, the first lens  100 , the second lens  201 , the third lens  202  and the array lens  300  are each on the optical axis. 
     When the light source is a laser light source, if the first direction is the fast axis, the first lens  100  can be a fast axis cylindrical lens, the second lens  201  can be a slow axis cylindrical lens, and the third lens  202  can be a slow axis cylindrical lens, and the array direction of the array lens  300  is arranged along the slow axis direction. 
     When the first direction is the slow axis, the first lens  100  is a slow axis cylindrical lens, the second lens  201  is a fast axis cylindrical lens, the third lens  202  is a fast axis cylindrical lens, and the array direction of the array lens  300  is arranged along the fast axis direction. 
     Furthermore, the first lens  100  is an ellipsoidal surface lens, that is, when the first lens  100  is a fast-axis cylindrical lens, it can be a fast-axis ellipsoidal surface lens, and when the first lens  100  is a slow-axis cylindrical lens, it can be a slow-axis ellipsoidal surface lens. 
     The second lens  201  is a hyperboloid lens, and its incident surface is a hyperboloid, so that the single lens not only realizes the expansion of the light beam, but also realizes the conversion from Gaussian light to flat-top light, which simplifies the optical structure. 
     The array of the array lens  300  is arranged along the second direction of the main optical axis, that is, when the second lens  201  is a slow-axis cylindrical lens, the array direction of the array lens  300  is arranged along the slow-axis direction; and when the second lens  201  is a fast-axis cylindrical lens, the array direction of the array lens  300  is arranged along the fast axis direction. 
     The fast axis and the slow axis of each lens in the optical module are interchangeable. As shown in  FIG.  1   , the present embodiment is specifically described, wherein the first lens  100  is a fast-axis cylindrical lens, the second lens  201  is a slow-axis hyperboloid mirror, and the third lens  202  is a slow-axis cylindrical lens. The exiting surface of the first lens  100  is a convex surface, the incident surface of the second lens  201  is a hyperboloid, and the exiting surface of the third lens  202  is a convex surface. The optical path diagram of it is shown in  FIG.  2   . 
     When the fast and slow axes are interchanged, that is, the first lens  100  is a slow-axis cylindrical lens, the second lens  201  is a fast-axis hyperboloid lens, and the third lens  202  is a fast-axis cylindrical lens. The optical path diagram of it is shown in  FIG.  3   . 
     The function of the first lens  100  is to compress, gather and collimate the light beam emitted by the light source, and the laser beam emitted by the light source is expanded along a single direction, i.e., the fast axis or the slow axis, through the second lens  201 , and realizes the conversion from the Gaussian light to the flat-top light. The third lens  202  collimates the light beam and completes the correction of the edge beam at the same time. The exiting surface of the array lens  300  is configured to emit light and cut the light spot. The light beam, which is output after passing through the first lens  100 , the second lens  201  and the third lens  202  in sequence, is cut into a light-spot combination of points and/or lines, on the slow axis, so as to form a light spot in the light exiting direction. 
     This embodiment provides the optical module, wherein a first lens  100 , a second lens  201  and an array lens  300  are arranged in sequence along the main optical axis. The first lens  100  compresses, converges and collimates the light beam emitted by the light source. The laser beam output from the light source is converted from Gaussian light to flat-top light through the second lens  201 . The exiting surface of the array lens  300  is configured to emit light and cut the light spot. The first lens  100  shapes the beam along the first direction of the main optical axis, and the second lens  201  shapes the beam along the second direction of the main optical axis. The array of the array lenses  300  is arranged along the second direction of the main optical axis. The first lens  100 , the second lens  201  and the array lens  300 , which are combined and matched, are configured so that the laser beam enters the second lens  201  after passing through the first lens  100 . The second lens  201  expands the laser beam, converts the Gaussian distribution of the laser beam into a flat-top distribution, and then it is exited through the array lens  300 . By arranging three optical elements, it can be realized that the original Gaussian distribution of the laser beam is converted into a flat-top distribution, so that the optical module is small in volume. 
     The optical module provided in this embodiment can also emit light spots of different shapes. 
     When an existing optical module forms a light spot, one optical module can only output light spots of a single form. For example, the output light spot can only be one of a single-point light spot, point-column light spots, point-matrix light spots, a line light spot, a surface light spot or a strip light spot. In this way, the optical module outputting a single light spot is only suitable for one industry demand. However, if a new demand arises, a new optical system is required to meet the new demand. While the single light spot output by the existing optical module can only solely corresponds to the new demand, for satisfying the use. In the case of cross-industry application, the original optical module cannot be applied to the needs of the new industry and thus fails. If it is the cross-industry application, a new set of optical modules needs to be redesigned. Compared with the original optical module, the individual optical components are changed greatly, and the overall structure of the original optical module will be changed, with high implementation cost, and the changed one can only be used in the original industry. Therefore, such an optical module has poor applicability, the cost of modification is high, and the light spots cannot be converted to each other. Once a new demand arises, the original optical module will fail, and the applicability is poor; and the light spot cannot be changed during the scanning process, with the scanning form being single. 
     On this basis, the optical module provided by the present application can form the light spots with various shapes, such as, row points, array points, the line shape, the plane shape or the strip shape, etc., by slightly adjusting the optical elements in this optical module. The light spots are in the diversified forms and can be converted between each other, with strong applicability, and can be used for cross-industry output, adapting to different needs, with powerful functions, high flexibility, low cost, small size, simple structure, and can be used in medical beauty (skin rejuvenation, fine hair removal and dissolving of fattiness). The matrix output is used in 3D recognition, active scanning source and laser printing and other fields. 
     When the light output range of the exiting surface of the array lens  300  is changed, the light spots formed by the output are changed in various ways, so as to output light spots of different shapes. 
     By changing the light output range of the exiting surface of the array lens  300 , light spots of different shapes can be emitted, so that one optical module can achieve the purpose of converting the light spots. In this way, in practical application, this optical module can be applied across industry, with high applicability, and one optical module can be used in different occasions to meet different needs. 
     Specifically, the light spot conversion (transformation) is realized through the following embodiments. 
     The array lens  300  comprises a plurality of first arc surfaces or a sawtooth surface continuously formed along the second direction, and the first arc surfaces or the sawtooth surface are located on the incident surface or the exiting surface of the array lens  300 . 
     The array lens  300  further comprises a plurality of second arc surfaces or a sawtooth surface arranged along the first direction, and the second arc surfaces or the sawtooth surface are located on the incident surface or the exiting surface of the array lens. 
     Exemplarily, as shown in  FIG.  1   , the exiting surface of the array lens  300  comprises a plurality of first arc surfaces continuously formed along the second direction, and the first arc surfaces are convex toward the light exiting direction, so that the exiting surface of the array lens  300  forms a pattern of plural connected strips, the light spot of the stripe shape is emitted. 
     As shown in  FIGS.  1  and  2   , the second lens  201  is a slow-axis cylindrical lens, and the first direction is the slow-axis direction, that is, a plurality of first arc surfaces are formed continuously along the slow-axis direction on the exiting surface of the array lens  300 , to emit the stripe shape light spot shown in  FIG.  4   . 
     The incident surface of the array lens  300  is a flat, convex or concave surface, and the exiting surface of the array lens  300  is formed of a plurality of first arc surfaces or a sawtooth surface. Or, the incident surface of the array lens  300  is formed of a plurality of first arc surfaces or a sawtooth surface, and the exiting surface of the array lens  300  is a flat, convex or concave surface. 
     Exemplarily, the incident surface of the array lens  300  can be a flat surface as shown in  FIG.  1    and  FIG.  5   . The incident surface of the array lens  300  can also be a sawtooth surface as shown in  FIG.  14   . As shown in  FIG.  16   , the incident surface is a sawtooth surface. The sawtooth of the incident surface are arranged along the second direction. The light beam emitted from the exiting surface of the third lens  202  is cut into a two-dimensional point array as shown in  FIG.  15    to form an array-point light-spot distribution of angular space. The third lens  202  can also be integrated with the array lens  300 , that is, when the incident surface of the array lens  300  is a convex surface as shown in  FIG.  19   , it can be regarded as the third lens  202  being capable of being integrated with the array lens  300 . In this way, the same exiting effect can be achieved, but the number of the optical components of the optical module is reduced, so that the structure of the optical module is simpler. 
     The incident surface or exiting surface of the array lens  300  comprises a plurality of first arc surfaces formed continuously along the second direction. The incident surface or the exiting surface of the array lens  300  further includes a plurality of second arc surfaces continuously arranged along the first direction, on the basis of the plurality of first arc surfaces. 
     Exemplarily, as shown in  FIG.  5   , the exiting surface of the array lens  300  comprises a plurality of first arc surfaces formed continuously along the second direction, and the exiting surface of the array lens  300  also comprises a plurality of second arc surfaces continuously arranged along the first direction, on the basis of the plurality of first arc surfaces, so that the exiting surfaces of the array lens  300  form a plurality of intersecting and perpendicular grids, wherein the exiting surfaces of the plurality of grids are also convex toward the light outgoing direction. Therefore, the exiting surfaces of the array lens  300  form convex parts of the array, so as to emit the row-point light spot or the array-point light spot. 
     The first arc surface and the second arc surface intersect to each other, to form a grid-like exiting surface. Each grid can emit one point light spot correspondingly, and the entire optical module emits the array-point light spot. 
     When the exiting surface forms a second arc surface on the basis of forming the first arc surface, as shown in  FIG.  6   , the emitted light spot can be changed from the original strip-shape light spot to a single-row point light spot. 
     The surface type of the incident surface and the surface type of the exiting surface of the array lens  300  can also be interchanged with each other. As shown in  FIG.  5    above, the exiting surface forms grids in the arrangement, and alternatively, they can also be set on the incident surface. As shown in  FIG.  17   , the incident surface of the array lens  300  includes a plurality of first arc surfaces continuously formed along the second direction. The first arc surface is convex toward the direction of the light source. The exiting surface of the array lens  300  is a sawtooth surface. The sawtooth of the sawtooth surface are arranged along the first direction. 
     It is also possible that the incident surface of the array lens  300  is a sawtooth surface arranged along the first direction, and the exiting surface of the array lens  300  is formed of a plurality of first arc surfaces arranged along the second direction. 
     Alternatively, as shown in  FIG.  16   , the incident surface of the array lens  300  is a sawtooth surface, and the exiting surface of the array lens  300  can also be a sawtooth surface. At this time, the sawtooth surfaces can be arranged along the first direction, and can also be arranged along the second direction. 
     The varied light spots are formed by exchanging the incident surface and the exiting surface of the array lens  300 . 
     The array lens  300  may also be an array reflecting mirror, and a plurality of first arc surfaces or sawtooth are continuously formed on the reflecting surface of the array reflecting mirror along the second direction. The sawtooth are arranged in the second direction. 
     Furthermore, the array lens  300  can reciprocate along the sawtooth arrangement direction, or rotate along the main optical axis direction. As shown in  FIG.  18   , in the fast axis direction, that is, the first lens  100  is a slow axis cylindrical lens, the second lens  201  is a fast axis cylindrical lens, the third lens  202  is a fast axis cylindrical lens, and the array direction (i.e., the array direction of the sawtooth) of array lens  300  is arranged along the fast axis direction. The array lens  300  can reciprocate along the sawtooth arrangement direction to change the light output range of the array lens  300  to form a varied light spot. 
     It is also possible that the array lens  300  can be separated into two lens arrays, which respectively have a plurality of first arc surfaces and a sawtooth surface that are each continuously formed along the first direction and are perpendicular to each other. That is to say, the array lens  300  comprises a first array lens and a second array lens, and the first arc surfaces or sawtooth surface are located on the incident surface or the exiting surface of the first array lens, and/or the incident surface or the exiting surface of the second array lens. 
     That is to say, the first arc surfaces or the sawtooth surface is located on the incident surface of the first array lens, or the first arc surfaces or the sawtooth surface are located at the exiting surface of the first array lens, or the first arc surfaces or sawtooth surface are located on the incident surface of the second array lens, or the first arc surfaces or the sawtooth surface are located on the exiting surface of the second array lens, or the incident surface and the exiting surface of the first array lens, and the incident surface and the exiting surface of the second array lens can be any one of the first arc surfaces or the sawtooth surface, and the first arc surfaces and the sawtooth surface can be randomly combined and arranged on the incident surface or the exiting surface of the two array lenses. 
     Exemplarily, as shown in  FIG.  17   , the incident surface of the first array lens comprises a plurality of first arc surfaces continuously formed along the second direction. The first arc surfaces are convex toward the light source, and the exiting surface of the second array lens is the sawtooth surface. The sawtooth arrangement direction of the sawtooth surface is perpendicular to the second direction. 
     Herein, exemplarily, as shown in  FIG.  18   , the tooth surfaces of the sawtooth have curvature. 
     The first lens  100  is movable along the main optical axis to change the light output range of the exiting surface of the array lens  300 . When the light output ranges of the exiting surfaces of the array lens  300  are different, the shapes of the light spots formed are also different. 
     By moving the first lens  100  along the main optical axis, the distance between the first lens  100  and the light source is changed, and meanwhile the distance between the first lens  100  and the second lens  201  is also changed accordingly, so that after the light beam emitted by the light source passes through the first lens  100 , the light output range of the light beam changes, and finally the different light spots can be formed through the exiting surface of the array lens  300 . 
     For example, the optical module shown in  FIG.  2    can emit a strip-shape light spot as shown in  FIG.  4   . When the distance between the first lens  100  and the light source decreases, that is, the distance between the first lens  100  and the second lens  201  increases, after the light source passes through the first lens  100 , the light output range of the light increases. The area of the strip-shape light spot originally formed by the exiting surface of the array lens  300  is increased, and gradually it is changed into a rectangular light spot or even a square light spot. 
     As shown in  FIG.  6   , the distance between the first lens  100  and the light source gradually increases, the light output range gradually decreases, and the originally formed strip-shape light spot can be changed to a row-point light spot. 
     As shown in  FIG.  7   , along with the distance between the first lens  100  and the light source being gradually decreased, the light output range gradually increases, and the originally emitted single-row point light spot gradually become the multi-row point light spot, i.e., the array light spot. 
     The smaller the distance between the first lens  100  and the light source is, the larger the light output range of the light is after the light source passes through the first lens  100 , and the larger the formed light spot range is. 
     A reflecting mirror  400  is also provided between the second lens  201  and the array lens  300 . As shown in  FIG.  8    and  FIG.  9   , when the third lens  202  is provided, the reflecting mirror  400  is located between the second lens  201  and the third lens  202 . The reflecting mirror  400  can change the light exiting direction of the light. 
     When the reflecting mirror  400  does not rotate, the reflecting mirror  400  can change the light exiting direction of the light, and the light spot formed by it does not change. 
     The reflecting mirror  400  is rotatable along the main optical axis to scan the light spot, so as to change the light output range of the exiting surface of the array lens  300 , so that the light spot has different variations, and the rotation angle of the reflecting mirror  400  is 0° to 90°, so as to continuously rotate and scan the light spot within the rotation angle. 
     For example, when the reflecting mirror  400  does not rotate, a strip-shape light spot or a point light spot can be formed as shown in  FIG.  6   . The exiting surface of the array lens  300  is formed of a plurality of first arc surfaces, which can form a strip-shape light spot. The exiting surface of the array lens  300 , on the basis of the plurality of first arc surfaces, are also provided with a plurality of second arc surfaces, which can form the point light spot. At this time, the reflecting mirror  400  only changes the light exiting direction of the light, so that the position where the light spot is formed changes, but the shape of the formed light spot does not change. 
     When the reflecting mirror  400  is rotated to scan, the reflecting mirror  400  can be rotated along the main optical axis to form a light spot in a larger range. For example, as shown in  FIG.  10   , the single-row point light spot spreads to the single-row point light spots on both sides, and finally an array-point light spot is formed. Alternatively, as shown in  FIG.  12   , the single-stripe light spot spreads to both sides, and finally the plural-stripe light spot is formed. When the rotation angle of the reflecting mirror  400  increases, it is formed that the array-point light spot, as shown in  FIG.  11   , spreads to both sides, forming an array-point light spot of the larger range. Alternatively, as shown in  FIG.  13   , the surface light spot spreads (is diffused) to the two sides to form the surface light spot of the larger area. 
     The larger the rotation angle of the reflecting mirror  400  is, the larger the light output range scanned by the reflecting mirror  400  is, and a light spot with more array points or a surface light spot with a larger area is more capable of being formed. 
     When the reflecting mirror  400  rotates, the light spot of a larger range is scanned to form light spots of different shapes. At this time, the distance between the first lens  100  and the light source may or may not be changed. When the distance between the first lens  100  and the light source does not change, the light spots of the wider range can be scanned only by rotating the reflecting mirror  400 , to obtain the conversion of the light spot. When the distance between the first lens  100  and the light source changes, and the reflecting mirror  400  is still rotated, on the basis that the reflecting mirror  400  rotates to scan light spots of the larger range, because the distance between the first lens  100  and the light source is changed, the range of the output light spot is changed. The effect of the spot conversion finally formed is multiplied after the two work together, that is, there are more conversion forms of the light spots, and more types and shapes of light spots can be formed. 
     The converted light spot can also be formed by defocusing. Defocusing means that when the optical module is specifically applied to actual use, the light spot formed by the optical module acts on the working surface. The distance between the working surface and the focal point where the light spot is formed can be selected to form the conversion of the light spot. Using this (conversion) transformation of the light spots, the corresponding application is completed through the working surface. 
     To sum up, in order to output different light spots and achieve the purpose of converting the light spots, it is possible to change the distance between the first lens  100  and the light source (the movement variable N1), the shape of the exiting surface of the array lens  300  (the switching variable N2), defocus (the defocus variable N3) and the rotational scanning of the reflecting mirror  400  (the scanning variable N4), to form light spots with different variations. 
     The above-mentioned ways of converting light spots can be used alone or in combination. When used in combination, they can be partially or completely combined. When the above-mentioned ways of converting light spots are used in combination, the types of light spots to be converted=N1*N2*N3*N4. 
     For example, when the exiting surface of the array lens  300  is a grid-like protrusion as shown in  FIG.  8   , the row point light spot shown in  FIG.  7    can be formed, and then the range of the formed row point light spot is changed by adjusting the distance between the first lens  100  and the light source, forming a single-row point or multi-row point as shown in  FIG.  7   , up to the array-point light spot. 
     The multi-row point light spot is an array light spot, and the row point light spot can be regarded as one kind of array-point light spot. 
     On this basis, the reflecting mirror  400  can also be rotated, and the reflecting mirror  400  is rotated to scan the formed light spot, so as to further change the light output range and form the conversion of the light spot. 
     As shown in  FIG.  10    and  FIG.  11   , the range of the single-row point light spot or the array-point light spot can be further expanded to the rotation direction of the reflecting mirror  400 , such as, forming a stripe-shape light spot. As shown in  FIGS.  12  and  13   , the range of the scanned stripe-shape light spot is further expanded. 
     To sum up, the shape of the light spot can be changed by means of changing the shape of the array lens  300 , changing the distance between the first lens  100  and the light source, rotating the reflecting mirror  400  or defocusing. According to the above different combination manners, different light spots can be formed to achieve the purpose of converting the light spots, so that the formed light spots have diversification. 
     When the above embodiments are applied to specific scenarios, such as, the medical industry, as shown in  FIG.  20    and  FIG.  21   , this embodiment provides a medical laser device, including a casing, a laser  501  which is arranged in the casing, and an optical module of the above-mentioned embodiment which is arranged in the exiting direction of the laser  501 . 
     A laser  501  is arranged in the casing, and the laser light emitted by the laser  501  is used as a light source. Through an optical module, a convertible light spot is emitted, and light spots of different shapes are applied to different treatments. 
     Specifically, the casing comprises a handle  503 , a spacer  504  and a lens barrel  506 . The handle  503  is convenient for the user to hold. The laser  501  is arranged in the spacer  504 , the optical module is arranged in the lens barrel  506 , and the lens barrel  506  and the spacer  504  are detachably connected. 
     The spacer  504  is provided therein with the heat sink  502 , which is connected to the laser  501 , to dissipate heat from the laser  501 . 
     The detachable connection can facilitate the replacement of the lens barrel  506 . In different lens barrels  506 , it can correspond to different combinations in the optical module, such as, whether to provide the reflecting mirror  400  or the third lens  202 . 
     Further, the front end of the lens barrel  506  is provided with a replaceable head  5061 , the replaceable head  5061  is detachably connected to the lens barrel  506 , and the array lens  300  is located in the replaceable head  5061 , which also facilitate replacing the different array lens  300 . 
     It also comprises a first motor  505 A and a second motor  505 B. The first motor  505 A and the second motor  505 B are respectively connected to the first lens  100  and the array lens  300 . The first motor  505 A drives the first lens  100  to move on the main optical axis, to change the distance between the first lens  100  and the laser  501 . The second motor  505 B drives the array lens  300  to translate. 
     As shown in  FIG.  19   , when the optical module comprises the reflecting mirror  400 , it also comprises a third motor  505 C, and the third motor  505 C is connected to the reflecting mirror  400  to drive the reflecting mirror  400  to rotate. 
     As shown in  FIG.  20   , the light spot formed by the array lens  300  can be used for treatment and other work, and the distance between the working surface and the focal point of the array lens  300  can be adjusted. 
     As shown in  FIG.  22   , when the working surface is at the focal position G of the array lens  300 , skin rejuvenation treatment can be performed. When the working surface is far away from the focal position of the array lens  300 , for example, at the G1 position, which is called as defocusing, the light spot formed at the defocusing position is different from that at the focal point, so that defocusing is another way of converting the light spot, and the hair removal treatment or the fat-dissolving treatment can be performed at the defocusing position. 
     The medical laser device comprises the structure and beneficial effects same as those in the foregoing embodiments. The structure and beneficial effects of the optical module have been described in detail in the foregoing embodiments, and not be repeated here. 
     Only preferred embodiments of the present application are provided above, and not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements or improvements, etc., made within the spirit and principle of the present application, shall be covered by the protection scope of the present application.