CN111375890A

CN111375890A - Composite light spot laser system based on multiple optical fiber output laser modules and processing head

Info

Publication number: CN111375890A
Application number: CN201910750129.7A
Authority: CN
Inventors: 方强; 方笑尘
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-08-14
Filing date: 2019-08-14
Publication date: 2020-07-07
Also published as: WO2021027659A1

Abstract

The invention discloses a composite light spot laser system and a processing head based on a plurality of optical fiber output laser modules, wherein a plurality of low-power light sources are directly utilized to generate composite light spots through an optical system, and the processing head is manufactured by utilizing the laser system and comprises a plurality of optical fiber output laser modules, a plurality of collimating lenses corresponding to the optical fiber output laser modules and a focusing lens; the end face of an output optical fiber of the optical fiber output laser module is positioned near the front focus of the corresponding collimating lens, and the collimating lens at least comprises a lens; the focusing lens at least comprises a lens and is positioned behind the collimating lens. The invention avoids the use of a high-power laser beam combiner, the laser output is dispersed at a plurality of points, the heat concentration is avoided, and the reliability problem caused by the beam combiner is avoided; the quality of the light beam is improved; the thermal problem in the laser optical system can be greatly eliminated by adopting a technical means; by dispersing the heat problem and taking heat conducting measures, the influence of the heat effect can be greatly reduced, and the reliability and the characteristics of the system are improved.

Description

Composite light spot laser system based on multiple optical fiber output laser modules and processing head

Technical Field

The invention relates to a laser system and a processing head, in particular to a composite light spot laser system based on a plurality of optical fiber output laser modules and a laser processing head using the same, belonging to the technical field of laser processing and being widely applied to the laser processing industry.

Background

Laser processing applications require laser spots of various structures to ensure laser processing effects. Such as: a composite spot with large center power and small edge power for welding or cutting, see fig. 1-1A; a multi-spot for welding, see FIGS. 1-1B and 1-2; strip-shaped light spots, rectangular light spots, circular light spots and the like for cladding, welding and quenching are shown in figures 1-3.

At present, the light spots shown in fig. 1-1A are realized by generally using dual-wavelength light sources, the light paths are shown in fig. 2-1, light with different wavelengths emitted by two light sources L1 and L2 are collimated by collimating lenses CL-1 and CL-2, and then combined by a wave combiner WC to form superposed light spots on a focal plane by the same focusing lens. In addition, another way to realize the light spot shown in fig. 1-1A is to use a dual focal length focusing lens, the radius of curvature of the central region and the edge region of the lens are different, two focal lengths are formed in one lens, the light output from the optical fiber passes through the collimating lens and the dual focal length lens to form two focal points along the axial direction, and the distribution shown in fig. 1-1A is generated on the section perpendicular to the optical axis. The spot shown in fig. 1-1B can reduce metal sputtering when used in welding, and currently, FL-ARM technology is developed in finnish factories of coherent companies, which consists of an annular laser combiner and a special optical fiber including a central core and an annular core, wherein the central core of the optical fiber outputs a central spot and the annular core outputs an annular spot. The optical path for realizing 3 light spot spots shown in fig. 1-2 is as shown in fig. 2-2A, after light output by a certain optical fiber light source L is collimated by a collimating lens CL, the collimated light is divided into 3 areas by a light beam splitter BS in a parallel optical path, relative deflection exists among the light of the three areas, the light is shaped and homogenized by a lens array LA, then 3 light spots are formed on the back focal plane of a refocusing lens FC, and the power of each light spot is determined by the size of the divided area. Fig. 2-2B show a schematic of one possible arrangement of beam splitters and lens arrays, with only one lens array LA0 on the largest area to form the main spot and BS1, LA1 and BS2, LA2 on the other two areas to produce the two auxiliary spots required. The beam splitter that produces the deflection is typically an optical wedge. The strip, rectangular and circular light spots shown in fig. 1-3 can be realized by the light paths shown in fig. 2-3, after the light output by a certain optical fiber light source L is collimated by a collimating lens CL, a lens array LA is arranged near the front focal plane of a converging lens in the parallel light path, and then the light is converged on the back focal plane by a focusing lens FC.

These spot techniques described above are implemented using one or two different wavelength light sources, which are expensive high power light sources. In reality, these light sources are usually obtained by combining light sources with small power. Thus, the generation of the laser processing spot can be seen as being achieved by the following path: a plurality of small-power laser modules, a beam combiner and a laser optical system. Namely, the low-power laser is changed into the high-power laser through beam combination, and then the high-power laser spot is changed into the required spot through an optical system.

In such a technical path as described above, there are the following problems:

the technical problem in the system is as follows: 1. in the beam combining process of the laser, the beam combiner has to deal with the inevitable leakage light in the beam combining process, and the heat management is very difficult, so that the reliability of the device is low; 2. the beam combiner is not perfect, so that the beam quality is seriously deviated from the level which can be reached by the theory, and the design of a subsequent laser optical system is difficult; 3. the laser optical system can absorb heat under the action of high-power laser to cause temperature rise, and because glass is a poor heat conductor, the lens can only be cooled at the edge through the lens frame, so that the central temperature of the lens is high, a so-called thermal lens effect is formed, and the higher the power is, the more obvious the thermal lens effect is, light spot drift can be generated, and the processing quality is influenced.

Secondly, the cost problem is as follows: 1. the high-power beam combiner is very expensive, and the unit power price of the high-power laser is usually about 2 times of that of the low-power laser module; 2. the generation of composite light spots needs special optical elements such as lens arrays, special optical fibers and the like, and only a few companies can produce the elements internationally at present, so that the processing is difficult and the price is high.

Finally, the current technical solution cannot completely meet the higher characteristic requirements of laser processing on laser equipment: according to the technical scheme at present, once the system is designed and shaped, the light spot structure is fixed in practical application, namely the light spot distribution area is fixed and the relative energy distribution of different areas is fixed, and because the requirements of the application of different materials and different scenes on the light spots are greatly different, the adaptability of the traditional equipment is poor, a user needs to purchase a large amount of equipment to meet different requirements, and the cost is greatly increased.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide a composite light spot laser system and a processing head based on a plurality of optical fiber output laser modules.

In order to achieve the above object, the technical solution of the present invention is summarized as follows:

a composite light spot laser system based on a plurality of optical fiber output laser modules is characterized by comprising a plurality of optical fiber output laser modules, a plurality of collimating lenses corresponding to the optical fiber output laser modules and a focusing lens; the end face of an output optical fiber of the optical fiber output laser module is positioned near the front focus of the corresponding collimating lens, and the collimating lens at least comprises a lens; the focusing lens at least comprises a lens which is positioned behind the collimating lenses; the output fiber end face of each fiber output laser module is focused by a focusing lens to be near the back focus after passing through a corresponding collimating lens, and the image points are combined to form a composite light spot.

The optical axes of the collimating lenses are parallel and are arranged in parallel in space; the optical axis of the focusing lens is parallel to the optical axis of the collimating lens; the cross-section of the core of the fiber output laser module output fiber is circular or rectangular in shape.

By adjusting the position of the fiber output end face of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, images formed by the fiber output end faces of the fiber output laser modules near a focal plane after passing through the corresponding collimating lens and the focusing lens are superposed together to form a single light spot, and the intensity of light spot areas is the same; or the middle power in the spot area is high and the edge power is low.

By adjusting the position of the fiber output end face of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, images formed by the fiber output end faces of the fiber output laser modules near the focal plane after passing through the corresponding collimating lens and the focusing lens are arranged into a strip-shaped light spot or a rectangular light spot.

By adjusting the position of the output end face of the optical fiber of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, the output end face of the optical fiber output laser module forms images near the focal plane after passing through the corresponding collimating lens and the focusing lens to form light spots distributed in a plurality of separated areas.

By adjusting the position of the fiber output end face of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, the image formed by the fiber output end face of the fiber output laser module near the focal plane after passing through the corresponding collimating lens and the focusing lens forms light spots arranged along the direction of the optical axis of the lens.

The position, the fiber core shape, the fiber core size and the focal length of the corresponding collimating lens of the fiber output end surface of the laser module are adjusted, so that the image formed by the fiber output end surface of the fiber output laser module near the focal plane after passing through the corresponding collimating lens and the focusing lens forms a light spot with an annular structure; or forming a light spot consisting of a light spot with an annular structure and a point-shaped light spot positioned at the center of the annular light spot.

The relative durations of light emission by the fiber output laser modules are the same or different; the power of each fiber output laser module in the relative duration of light emission is the same or different; the relative durations of light emission by the fiber output laser modules are synchronous or asynchronous; the light spot structure with the light spot shape changing along with time is formed, and the requirements of different laser processing on the light spots are met.

The invention also provides a laser processing head based on the composite facula laser system, which comprises a plurality of optical fiber output laser modules, a plurality of collimating lenses corresponding to the optical fiber output laser modules, a focusing lens, an optical fiber support, a collimating lens support, a focusing lens support and a tubular shell. The output ends of the output optical fibers of the plurality of optical fiber output laser modules are fixed on the optical fiber bracket; the plurality of collimating lenses are fixed on the collimating lens bracket; the focusing lens is fixed on the focusing lens bracket; the optical fiber support is fixed inside the tubular shell and close to one end, and the output end face of the optical fiber faces the other end of the tubular shell; the collimating lens holder is disposed inside the tubular housing and abuts the fiber optic holder; the focusing lens support is fixed inside the tubular shell and is adjacent to the collimating lens group support; the light emitted by the output optical fiber end faces of the optical fiber output laser modules fixed on the optical fiber support passes through the corresponding collimating lens fixed on the collimating lens group support and then passes through the focusing lens fixed on the focusing lens group support to generate the required composite laser spot.

At least one surface of at least one lens in the focusing lenses is attached to a corresponding lens frame which is processed by good heat conduction materials and has the same surface type on the focusing lens support, and the area corresponding to collimated light on the lens frame is hollowed out to allow corresponding light beams to penetrate; the lens mounting structure can greatly increase the heat dissipation capacity of the lens.

Compared with the prior art, the invention has at least the following beneficial effects: 1. the technical scheme of the invention greatly reduces the difficulty in processing the thermal problem: 1) the use of a high-power laser beam combiner is avoided, the laser output is dispersed at a plurality of points, the heat concentration is avoided, and the reliability problem caused by the beam combiner is avoided; 2) the thermal problem in the laser optical system can be greatly eliminated by adopting a technical means; by dispersing the heat problem and adopting heat conducting measures, the influence of the heat effect can be greatly reduced, and the reliability and the characteristics of the system are improved; 2. the technical scheme of the invention improves the beam quality, and can reduce the numerical aperture of the lens, reduce the number of lens pieces and further reduce the heat effect of the system under the condition of the same power and light spot size.

Furthermore, the invention avoids the use of a beam combiner, thereby reducing the system cost; in the laser optical system, all the conventional optical elements are adopted, so that the cost of the laser optical system can be greatly reduced, and the reliability of the system is improved; in addition, the invention can reduce the cost of the composite light spot laser processing system.

Furthermore, the laser spot generated by the laser system has the capability of adjusting the spot structure in real time, the capability of changing the spot structure in real time which cannot be realized by the prior art is provided, the flexibility and the applicability of equipment are improved, and the equipment purchase cost of a user is saved.

Drawings

Fig. 1-1A is a schematic diagram of the cross-sectional energy distribution of a spot with large center power and small edge power.

Fig. 1-1B is a schematic diagram of the cross-sectional energy distribution of a composite spot composed of an annular spot and a spot located at the center of the annular spot.

Fig. 1-2A and fig. 1-2B are schematic diagrams of a multi-spot light spot structure for welding or cutting, respectively.

FIGS. 1-3A, 1-3B, and 1-3C are schematic diagrams of strip, rectangular, and circular light spot structures for cladding, welding, and laser heat treatment, respectively.

Fig. 2-1 is a schematic diagram of an optical path structure for realizing the light spot shown in fig. 1-1A.

Fig. 2-2A is an optical path diagram for implementing the spot structure shown in fig. 1-2; fig. 2-2B are schematic diagrams of optical path deflecting devices respectively located on 3 regions on the front focal plane of the optical path focusing mirror shown in fig. 2-2A.

FIGS. 2-3 are schematic diagrams of optical paths for generating the spots shown in FIGS. 1-3, with a micro-lens array disposed near the front focal plane of the focusing lens.

Fig. 3 is a schematic diagram of an optical path structure of a composite light spot laser system based on a plurality of optical fiber output laser modules according to the present invention.

Fig. 4A is an arrangement structure of collimating lenses and focusing lenses when a system composed of 7 collimating lenses is observed along the optical axis direction according to the technical scheme of the composite light spot laser system based on multiple fiber output laser modules provided by the present invention.

Fig. 4B is a schematic diagram of a stripe-shaped light spot structure generated by the technical solution of fig. 4A.

Fig. 4C is a schematic diagram of a structure of 3 separated light spots generated by the technical solution of fig. 4A.

Fig. 5A is an arrangement structure of collimating lenses and focusing lenses when a system composed of 6 collimating lenses is observed along the optical axis direction according to the technical solution of the composite light spot laser system based on multiple fiber output laser modules provided by the present invention.

Fig. 5B is a schematic diagram of a rectangular light spot structure generated by the solution of fig. 5A.

Fig. 6A is an arrangement structure of collimating lenses and focusing lenses when a system composed of 4 collimating lenses is observed along the optical axis direction according to the technical scheme of the composite light spot laser system based on multiple fiber output laser modules provided by the present invention.

Fig. 6B is a schematic diagram of an annular light spot structure generated by the technical solution of fig. 6A.

Fig. 6C is a schematic diagram of a rectangular annular light spot structure generated by the solution of fig. 6A.

Fig. 6D is a schematic structural diagram of a central spot of an edge ring-shaped spot generated by the technical solution of fig. 6A.

Fig. 7 is an arrangement structure of collimating lenses and focusing lenses when a system composed of 6 collimating lenses is observed along the optical axis direction according to the technical scheme of the composite light spot laser system based on multiple fiber output laser modules provided by the present invention.

FIG. 8 is a schematic diagram of a laser processing head system in accordance with the present invention utilizing a multiple spot laser system in accordance with the present invention based on multiple fiber output laser modules.

FIG. 9A is a schematic view of a focusing lens; FIG. 9B is a side view of a lens-bonded portion of a piece of focusing lens frame made of a good thermal conductor bonded to the lens shown in FIG. 9A; FIG. 9C is a schematic front view of a structure of a portion bonded to a lens in a single-piece focusing lens frame made of a good thermal conductor bonded to the lens shown in FIG. 9A;

wherein: l, L1 and L2 denote lasers, respectively; CL, CL-1, CL-2, …, and CL-M denote collimating lenses, respectively; FL represents a focusing lens, FL-1 represents a certain lens of the focusing lens; BS, BS-1 and BS-2 respectively represent light splitting devices; WC denotes a multiplexer; LA, LA0, LA1, LA2 denote microlens arrays, respectively; m-1, M-2, …, M-N represent fiber output laser modules, respectively. GXJ denotes a fiber holder; CLZJ denotes a collimating lens group holder; FLZJ denotes a focus lens holder, and FLJ-1A denotes a portion of a certain piece of lens holder on the focus lens holder; GZK denotes a tubular housing.

Detailed Description

The composite optical spot laser system based on a plurality of optical fiber output modules and the laser processing head using the same proposed by the present invention will be described in detail with reference to the accompanying drawings and embodiments.

Fig. 3 is a schematic diagram of an optical path structure of a composite spot laser processing head based on a plurality of optical fiber output modules according to the present invention. The device consists of N optical fiber output laser modules, M collimating lenses and a focusing lens. Wherein: m is less than or equal to N, namely the number of the collimating lenses is less than or equal to the number of the optical fiber output laser modules, the N optical fiber output modules M-1, M-2, … and M-N are divided into M groups, each group corresponds to one of the M collimating lenses CL-1, CL-2, … and CL-M, and the end face of the output optical fiber of each group of the optical fiber output laser modules is positioned near the front focal plane of the corresponding collimating lens; the focusing lens FL is positioned behind the M collimating lenses; the light output by the N optical fiber output laser modules passes through the corresponding collimating lenses and is imaged to the position near the back focal plane by the focusing lenses to form a composite light spot. According to the technical scheme, laser spots with various structures can be conveniently designed by adjusting the positions of the end faces of the output optical fibers of the optical fiber output laser modules M-1, M-2, … and M-N, the shape and parameters of the optical fiber core, the parameters of the collimating lenses CL-1, CL-2, … and CL-M and the parameters of the focusing lens FL.

In this solution, the optical axes of the M collimator lenses are generally parallel to each other and parallel to the optical axis of the focusing lens FL. The shape of the output optical cores of the fiber output laser modules M-1, M-2, …, M-N may be circular or rectangular.

In the technical scheme, images formed by the output fiber end faces of all the fiber output laser modules near the back focal plane of the focusing lens FL can be overlapped together to form a composite light spot by adjusting the positions of the output fiber end faces of the fiber output laser modules M-1, M-2, … and M-N, the shapes and parameters of the fiber cores, the parameters of the collimating lenses CL-1, CL-2, … and CL-M and the parameters of the focusing lens FL. The size of the image formed by the end face of the optical fiber corresponding to each collimating lens can be the same or different; when the images are different in size, a light spot structure with high power in the middle area and low power in the edge area can be formed.

In the technical scheme, images of the output fiber end faces of all the fiber output laser modules can be arranged into a strip-shaped light spot on the back focal plane of the focusing lens FL by adjusting the positions of the output fiber end faces of the fiber output laser modules M-1, M-2, … and M-N, the parameters of the collimating lenses CL-1, CL-2, … and CL-M and the parameters of the focusing lens.

In the technical scheme, images of the output fiber end faces of all the fiber output modules can be arranged into a rectangular light spot on the back focal plane of the focusing lens FL by adjusting the positions of the output fiber end faces of the fiber output laser modules M-1, M-2, … and M-N, the parameters of the collimating lenses CL-1, CL-2, … and CL-M and the parameters of the focusing lens.

In the technical scheme, images of the output fiber end faces of all the fiber output laser modules can be arranged into a light spot distributed on a plurality of separated areas on the back focal plane of the focusing lens FL by adjusting the positions of the output fiber end faces of the fiber output laser modules M-1, M-2, … and M-N, the parameters of the collimating lenses CL-1, CL-2, … and CL-M and the parameters of the focusing lens.

In this embodiment, the position of the output fiber end faces of the fiber output laser modules M-1, M-2, …, M-N, the parameters of the collimating lenses CL-1, CL-2, …, and CL-M, and the parameter of the focusing lens FL are adjusted so that the images of the output fiber end faces of all the fiber output laser modules formed near the back focal plane of the focusing lens FL are arranged at a plurality of points in the optical axis direction.

In the technical scheme, the positions of the output fiber end faces of the fiber output laser modules M-1, M-2, … and M-N, the parameters of the collimating lenses CL-1, CL-2, … and CL-M and the parameter of the focusing lens FL can be adjusted, so that the images formed by the output fiber end faces of all the fiber output laser modules near the back focal plane of the focusing lens FL are arranged into an annular structure, a circular ring structure or a rectangular ring structure.

In the technical scheme, images formed by the output fiber end faces of all the fiber output laser modules near the back focal plane of the focusing lens FL can be arranged into a light spot structure with an edge ring and a central point by adjusting the positions of the output fiber end faces of the fiber output laser modules M-1, M-2, … and M-N, the parameters of the collimating lenses CL-1, CL-2, … and CL-M and the parameter of the focusing lens FL.

In this embodiment, the fiber output laser modules may be a continuous light laser module, a quasi-continuous light laser module, or a pulsed laser module. That is, the relative durations of light emitted by the fiber output laser modules may be the same or different; the power of each fiber output laser module in the relative duration of light emission can be the same or different; the relative durations of light emission by the fiber output laser modules may or may not be synchronous; by controlling the light-emitting rules of the modules, a light spot structure with the light spot shape changing along with time can be formed, and the requirements of different laser processing on light spots are met.

FIG. 8 is a schematic diagram of a laser processing head system in accordance with the present invention utilizing a multiple spot laser system in accordance with the present invention based on multiple fiber output laser modules. The device comprises a plurality of fiber output laser modules M-1, M-2, … and M-N, a plurality of collimating lenses CL-1, CL-2, … and CL-M corresponding to the fiber output laser modules, a focusing lens FL, a fiber support GXJ, a collimating lens support ZZZJ, a focusing lens support FLZJ and a tubular shell GZK. Wherein: the output ends of the output optical fibers of the optical fiber output laser modules M-1, M-2, … and M-N are fixed on an optical fiber bracket GXJ; a plurality of collimating lenses CL-1, CL-2, …, and CL-M are fixed to the collimating lens holder ZZZJ; the focusing lens FL is fixed on the focusing lens bracket FLZJ; the optical fiber support GXJ is fixed at one end close to the inside of the tubular shell GZK, and the output end face of the optical fiber faces the other end of the tubular shell GZK; the collimating lens support ZZZJ is disposed inside the tubular housing GZK and abuts the fiber support GXJ; a focusing lens support FLZJ is fixed inside the tubular housing and abuts the collimating lens group support ZZZJ; the light emitted from the output fiber end of the fiber output laser modules fixed on the fiber support GXJ passes through the corresponding collimating lens fixed on the collimating lens group support ZZZJ and the focusing lens fixed on the focusing lens support FLZJ, and then the required composite laser spot is generated. The laser processing head can be used for generating various types of laser spot structures required at present, and various laser processing requirements such as laser cutting, laser welding, laser cladding, laser heat treatment, laser 3D printing and the like are met.

The technical scheme of the laser head can theoretically form laser processing light spots with various structures, and the light spots can have the capability of changing the structure of the light spots in real time.

In the technical scheme of the laser processing head, at least one surface of at least one lens in the lenses in the focusing lens is attached to a corresponding lens frame which is processed by good heat conduction materials and has the same surface type, and the area, corresponding to collimated light, on the lens frame is hollowed out to allow corresponding light beams to penetrate through. In an actual system, in order to meet various aberration requirements, a focusing lens is generally composed of a plurality of lenses, in order to enable each lens to radiate heat well, two surfaces of each lens are attached to a heat conducting plate with an optical channel as much as possible, and a certain gap is reserved between each lens through design so as to increase the heat radiating capacity of the heat conducting plate. The lens mounting structure can greatly increase the heat dissipation capacity of the lens. Fig. 9 gives a schematic view of such a lens mounting structure: FIG. 9A is a schematic view of a certain lens FL-1 in the collection lens; fig. 9B is a schematic side view of a partial structure FLJ-1A of the lens frame corresponding to a certain surface of the lens in fig. 9A, and fig. 9C is a schematic front view of a partial structure FLJ-1A of the lens frame corresponding to a certain surface of the lens in fig. 9A, wherein the surface of the partial structure FLJ-1A corresponding to the surface of the lens is the same as the surface of the lens, the partial structure FLJ-1A and the surface of the partial structure FLJ-1A are bonded together, and a through hole is formed in a region of the lens frame corresponding to a light transmitting portion of the. The material of the lens frame is a good heat conduction material, and copper or aluminum is usually adopted for processing.

Compared with the prior art, the technical scheme of the laser processing head has the following advantages in the aspect of heat management: 1. the adoption of a beam combiner is avoided, the problem of heat concentration is avoided technically, the leakage light generated by the output point of the laser module is dispersed in front of the M collimating lenses, and the heat leakage quantity of each point is greatly reduced; 2. the M collimating lenses are adopted, the size of the lenses is far smaller than that of the lenses adopted in the prior art, and for the poor heat conductor such as glass, the lenses are small in diameter, short in cooling path, good in heat dissipation effect, small in diameter, thin and small in heat effect; 3. the focusing lens is similar to the traditional lens, but because the laser beams are a plurality of spatially separated light beams, the surface of each lens in the focusing lens is coated by the hollow heat conducting plate made of the good heat conductor, the hollow part corresponds to the laser beams from the collimating lens, and because the heat conductivity coefficient of the good heat conductor is dozens of times to hundreds of times of that of glass, the cooling effect of the lens can be greatly improved by the scheme, and the heat effect of the lens can be ignored.

Example 1: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, the light synthesis of 49 optical fiber output laser modules into a light spot structure is required, and the diameter of the light spot is required to be 1.8 mm. The system adopts a structure of 7 collimating lenses and 1 focusing lens shown in FIG. 4A, the optical axes of the 7 collimating lenses are parallel, the focal lengths of the 7 collimating lenses are the same, and the front focal planes are coincident, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens and is coincident with the optical axis of the collimating lens at the center; the output power of the optical fiber output semiconductor laser module with the wavelength of 915 nanometers is 120 watts, the diameter of an output optical fiber core is 105 micrometers, the diameter of a cladding is 125 micrometers, and the numerical aperture is 0.22. The 49 laser modules are divided into 7 groups, the end faces of 7 output optical fibers in each group are aligned and arranged together in a structure of 6 fibers surrounding 1 fiber, and the end face of each group of optical fibers is positioned at the focus of the corresponding collimating lens; the focal length of the collimating lens is 30 mm, and the focal length of the focusing lens is 150 mm. The end faces of the optical fibers of each group form light spots with the diameter of 1.8 mm at the back focal point of the focusing lens. The laser system can be used in the fields of laser welding, cladding, 3D printing and the like.

Example 2: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, a light spot with high power in a central area and low power in an edge area is needed, 7 collimating lenses and 1 focusing lens structure shown in fig. 4A are adopted, the optical axes of the 7 collimating lenses are parallel, and the optical axis of a focusing lens FL is parallel to the optical axis of the collimating lens and is superposed with the optical axis of the collimating lens positioned in the center; in this embodiment, the 7 fiber output laser modules are fiber lasers with a wavelength of 1064 nm, the power is 500 to 1000 w, the core diameter of each module output fiber is 20 microns, the numerical aperture is 0.06, and the fiber cladding diameter is 400 microns. Of the 7 collimating lenses, 6 have a focal length of 50 mm, 1 has a focal length of 25 mm, the distance between the lenses is 8 mm, and the focal length of the focusing lens is 500 mm. The system forms a cutting light spot which is a superposition of a high-power light spot with the diameter of 200 microns and a low-power light spot with the diameter of 400 microns, and the numerical aperture of the high-power light spot is about 0.046. The system can be used for laser cutting, and is particularly suitable for cutting high-reflectivity metal. Because the metal surface reflection can be greatly reduced along with the temperature rise according to the properties of the metal, the low-power light spot in the system can preheat a high-power cutting area in advance, the reflectivity of the metal is greatly inhibited, and a laser system is protected.

In the embodiment, 6 laser modules forming 200-micron light spots are controlled in a unified mode, and one laser module forming 400-micron light spots is controlled independently, so that the power distribution of the light spots can be flexibly changed according to the actual processing technology requirements, and different processing requirements are met.

Example 3: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, a light spot with a sheet-shaped convergence structure is needed, the collimating lens and the converging lens in the light path adopt the structure shown in fig. 7, 6 lenses are arranged in one dimension in one plane, the optical axes of the 6 lenses are parallel, the focal lengths of the 6 lenses are the same, the front focal planes are coincident, the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens, and the distribution center of the 6 collimating lenses is coincident with the optical axis of the focusing lens. In this embodiment, the 6 fiber output laser modules are fiber lasers with a wavelength of 1064 nm, the power is 500 to 1000 w, the core diameter of each module output fiber is 20 microns, the numerical aperture is 0.06, the fiber cladding diameter is 400 microns, the focal length of the collimating lens is 50 mm, the lens spacing is 8 mm, and the focal length of the focusing lens is 500 mm. The system forms a cutting spot with a diameter of 200 microns, a numerical aperture of the converged beam in the narrow direction of 0.006, and a numerical aperture of the converged spot in the wide direction of about 0.046.

The laser system has excellent beam quality, is suitable for cutting thick plates with larger curvature radius, and can obtain good cutting quality and high cutting efficiency.

Example 4: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, two light spots are required to be formed at two points along the axial direction, the distance between the two light spots is 10 mm, and the size of each light spot is 1.8 mm. This embodiment utilizes 49 fiber output semiconductor laser modules with a wavelength of 976 nm, an output power of 120 watts, an output fiber core diameter of 105 microns, a cladding diameter of 125 microns, and a numerical aperture of 0.22. The system adopts a structure of 7 collimating lenses and 1 focusing lens shown in FIG. 4A, the optical axes of the 7 collimating lenses are parallel, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens and is superposed with the optical axis of the collimating lens positioned in the center; the focal lengths of the 7 collimating lenses are the same and are 30 mm, and the focal length of the focusing lens is 150 mm. The 49 laser modules are divided into 7 groups of 7, with 7 output fibers in each group aligned end-on, arranged together in 6 configurations around 1. The end face of each group of optical fibers is positioned near the focus of the corresponding collimating lens; dividing 6 groups of end surfaces positioned at the edge into two groups which are alternately arranged, and imaging the end surfaces at the position of 5 mm on the optical axis in front of the focus behind the focusing lens by adjusting the positions of 3 end surfaces in one group and the end surface positioned at the center in front of the collimating lens; another set of 3 end faces was imaged 5 mm on the optical axis after the back focus of the focusing lens by adjusting the position of the end faces near the front focus of the collimating lens. The light spot can obtain a light spot structure with high power at the center and low power at the edge at positions near two image points, and the power distribution can be changed along with the positions. The laser system can be used in the fields of laser welding, cladding, 3D printing and the like.

In this embodiment, the laser modules imaged at the same point are used as a group to be controlled in a unified manner, and laser spots with controllable central power and edge power can be obtained by adjusting the relative power of the two groups of modules, so that different laser processing process requirements are met.

Example 5: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, the light spot structure shown in fig. 4B is required to be realized as a strip-shaped light spot with the ratio of length to width of 7: 1. In this embodiment, the collimator lens adopts the structure shown in fig. 4A, the optical axes of the 7 lenses are parallel, the focal lengths of the 7 lenses are the same, and the front focal planes coincide, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimator lens and coincides with the optical axis of the collimator lens located at the center. In this embodiment, the fiber cores of the output fibers of the 7 fiber output modules are in a square structure, the fiber end surfaces of the output fibers are located on the front focal plane of the corresponding collimating lenses, the corresponding sides of the fiber cores are arranged in parallel, if the length of the fiber sides is denoted by D, and the distances from the focal point of the 7 fiber end surfaces in the direction parallel to one side of the fiber cores are set to be 3D, 2D, D, 0, -D, -2D and-3D, respectively, so that the light distribution shown in fig. 4B can be obtained on the rear focal plane of the converging lens. The light spot is widely applied to the fields of laser heat treatment and laser cladding.

Example 6: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, the light spot structure shown in fig. 4C is required to be realized and is a composite light spot consisting of a square light spot and two circular light spots. In this embodiment, the collimator lens has the structure shown in fig. 4A, and 7 lenses are arranged in the same plane with their optical axes parallel, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimator lens and coincides with the optical axis of the collimator lens located at the center. In this embodiment, the fiber cores of the output fibers of the fiber output modules corresponding to 5 lenses of the 7 lenses have focal lengths f1, 2 lenses of the 7 lenses have focal lengths f2, 5 lenses of the 5 lenses have focal lengths f1, the fiber end centers of the output fibers are located on the front focal plane of the corresponding collimating lenses, the corresponding sides of the fiber cores are arranged in parallel, the fiber cores of the output fibers of the fiber output modules corresponding to 2 lenses of the f2 have circular structures, and the fiber centers of the output fibers deviate from the focal point in two directions in the focal plane, so that the light distribution shown in fig. 4C can be obtained on the back focal plane of the converging lens. In the embodiment, parameters such as the wavelength of light waves, the size of the optical fiber core, the focal length of the lens and the like can be flexibly set, so that the design flexibility is increased. Such a spot is widely used in the field of laser welding.

In the embodiment, 5 laser modules corresponding to the square light spots are controlled in a unified mode, modules corresponding to 2 circular light spots are controlled in a unified mode, and power distribution of the square light spots and the circular light spots can be controlled to meet requirements of different laser processing technologies.

Example 7: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, the light spot structure shown in fig. 5B is required to be realized and is a rectangular light spot. In this embodiment, the collimating lens has the structure shown in fig. 5A, the 6 lenses are located on the same plane, the optical axes are parallel, the focal lengths of the 6 lenses are the same, the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens, and the distribution center of the 6 lenses coincides with the optical axis of the focusing lens. In this embodiment, the fiber cores of the output fibers of the 6 fiber output modules are in a square structure, the fiber end surfaces thereof are located on the front focal plane of the corresponding collimating lenses, the corresponding sides of the fiber cores are arranged in parallel, if D represents the length of the fiber side, the 4 fiber end surfaces are arranged in the coordinate system arranged in the direction parallel to the fiber core side at (-D, D/2), (0, D/2), (D, D/2), (-D, -D/2), (0, -D/2) and (D, -D/2), so that the light distribution shown in fig. 5B can be obtained on the back focal plane of the converging lens. Such a spot is widely used in the field of laser heat treatment.

Example 8: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, the annular light spot shown in fig. 6B is required to be realized, wherein the diameter of the annular light spot is 16 mm, and the annular cost is 2.1 mm. In this embodiment, the collimator lens and the focusing lens of the laser system adopt the structure shown in fig. 6A. The optical axes of the 4 collimating lenses are parallel, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens and is positioned at the symmetrical center of the optical axes of the 4 collimating lenses. A designed set of parameters is set as: the output power of the 48-wavelength 915 optical fiber output semiconductor laser module is 120 watts, the core diameter of the output optical fiber is 105 micrometers, the cladding diameter is 125 micrometers, and the numerical aperture is 0.22; the 48 modules are divided into 12 groups, the end faces of the output fibers are aligned, and the fiber axes are arranged on a circumference with the diameter of 800 microns at equal angular intervals; the focal length of the collimating lens is 20 mm, and the focal length of the focusing lens is 400 mm. By adjusting the position of each group of optical fiber end faces at the front focus of the collimating lens, each two groups of optical fibers can form a circular ring with the diameter of 16 mm and the optical fiber end faces arranged continuously on the rear focus of the focusing lens, and the two circular rings are staggered by half of the optical fiber image distance along the circumferential direction, so that a circular laser spot with high uniformity can be formed. The system can be used for laser welding of annular welding seams.

Example 9: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, the rectangular annular laser spot shown in fig. 6C is required to be realized, the size of the rectangular annular laser spot is 13.75 mm X11.25, and the width of the spot is about 1 mm. In this embodiment, the collimator lens and the focusing lens of the laser system adopt the structure shown in fig. 6A. The optical axes of the 4 collimating lenses are parallel, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens and is positioned at the symmetrical center of the optical axes of the 4 collimating lenses. A designed set of parameters is set as: the output power of the 40 optical fiber output semiconductor laser modules with the wavelength of 915 is 120 watts, the core diameter of the output optical fiber is 105 micrometers, the cladding diameter is 125 micrometers, and the numerical aperture is 0.22; the 42 modules are divided into 4 groups, wherein each group comprises 12 modules, and each group comprises 8 modules; the end faces of the output optical fibers are aligned and arranged at intervals of 125 microns along a straight line; the focal length of the collimating lens is 20 mm, and the focal length of the focusing lens is 200 mm. By adjusting the position of the end face of each group of optical fibers at the front focus of the collimating lens, four groups of optical fibers can form a rectangular annular laser spot of 13.75 mm X11.25 on the back focus face of the focusing lens, and the line width of the spot is about 1.05 mm. The system can be used for laser welding of rectangular annular welding seams.

Example 10: according to the technical scheme of the laser system based on the multiple optical fiber output laser modules, in one embodiment of the invention, the light spots shown in fig. 6D are required to be realized, namely, a central point-like light spot and an annular light spot surrounding the central point-like light spot are required to be realized, the diameter of the central point-like light spot is required to be 2 mm, the outer diameter of the annular edge light spot is required to be 6 mm, and the annular width is required to be 1 mm. In this embodiment, the collimator lens and the focusing lens of the laser system adopt the structure shown in fig. 6A. The optical axes of the 4 collimating lenses are parallel, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens and is positioned at the symmetrical center of the optical axes of the 4 collimating lenses. A designed set of parameters is set as: the output power of the 24-wavelength 915 optical fiber output semiconductor laser module is 120 watts, the core diameter of the output optical fiber is 105 micrometers, the cladding diameter is 125 micrometers, and the numerical aperture is 0.22; 2 fiber laser modules with the wavelength of 1064 microns, the output power of 1000 watts, the core diameter of an output fiber of 100 microns and the numerical aperture of 0.1. Wherein: the 24 semiconductor laser modules are divided into two groups, each group comprises 12 semiconductor laser modules, the end faces of output optical fibers of the semiconductor laser modules are aligned, the axes of the optical fibers are arranged on the circumference with the diameter of 500 micrometers at equal angular intervals, the focal length of a collimating lens corresponding to the optical fibers is 20 millimeters, and the focal length of a focusing lens is 200 millimeters; by adjusting the position of each group of optical fiber end faces at the front focus of the collimating lens, each group of optical fibers can form a circular ring with the diameter of 5 mm and continuously arranged optical fiber end faces on the rear focus of the focusing lens, and the two circular rings are staggered by half of the optical fiber image distance along the circumferential direction, so that a circular laser spot with high uniformity can be formed; the focal length of the collimating lens corresponding to the 2 fiber laser modules is 10 mm, and light spots with the diameter of 2 mm formed by the two fibers can be superposed together on the rear focal plane of the focusing lens by adjusting the position of the end face of each fiber at the front focal point of the collimating lens; this spot, together with the previous annular spot, constitutes the required laser machining spot. The laser spot is used for welding, can greatly inhibit metal sputtering in the welding process, avoids damage to a laser optical system and improves the quality of a welding seam.

In this embodiment, the laser modules corresponding to the annular light spots are controlled in a unified manner, the modules corresponding to the central point-like light spots are controlled in a unified manner, and the power distribution in different areas can be controlled to meet the requirements of different laser processing technologies.

Example 11: according to the technical solution proposed by the present invention for a laser processing head using a plurality of laser systems based on a plurality of fiber output laser modules proposed by the present invention, in one embodiment of the present invention, a laser processing head is required, the spot of which has a structure with high center power and low fringe area. The laser system adopts a structure of 7 collimating lenses and 1 focusing lens shown in fig. 4A, and the laser head adopts a structure shown in fig. 8, namely, the output ends of the output optical fibers of the optical fiber output laser modules are fixed on the optical fiber support; a plurality of collimating lenses are fixed on the collimating lens bracket; the focusing lens is fixed on the focusing lens bracket; the optical fiber support is fixed inside the tubular shell and close to one end, and the output end face of the optical fiber faces the other end of the tubular shell; the collimating lens support is disposed inside the tubular housing and abuts the fiber support; the focusing lens bracket is fixed inside the tubular shell and is adjacent to the collimating lens group bracket; the light emitted from the output fiber end of the fiber output laser modules fixed on the fiber support passes through the corresponding collimating lens fixed on the collimating lens group support and then passes through the focusing lens fixed on the focusing lens support to generate the required composite laser spot.

In this embodiment, the relevant technical parameters of the optical part are: the optical axes of the 7 collimating lenses are parallel, the focal lengths of the 7 collimating lenses are the same, the front focal planes are overlapped, and the optical axis of the focusing lens FL is parallel to the optical axis of the collimating lens and is overlapped with the optical axis of the collimating lens positioned in the center; in this embodiment, the 7 fiber output laser modules are fiber lasers with a wavelength of 1064 nm, the power is 500 to 1000 w, the core diameter of each module output fiber is 20 microns, the numerical aperture is 0.06, and the fiber cladding diameter is 400 microns. Of the 7 collimating lenses, 6 have a focal length of 50 mm, 1 has a focal length of 25 mm, the distance between the lenses is 8 mm, and the focal length of the focusing lens is 500 mm. The cutting light spot formed by the system is the superposition of a high-power light spot with the diameter of 200 microns and a low-power light spot with the diameter of 400 microns, the light spot with the diameter of 200 microns is formed by superposing output light of 6 laser modules, and the light spot with the diameter of 400 microns is generated by one module. The numerical aperture of the high power spot is about 0.046.

In this embodiment, the relevant parameters of the mechanical component are: the optical fiber support GXJ is a cylinder with the diameter of 30 mm, a through hole is formed in the central axis of the cylinder, and 6 through holes are uniformly formed in the circumference which takes the central axis of the cylinder as the center and has the diameter of 16 mm; the collimating lens support ZZZJ is a disc with the diameter of 30 mm, a through hole with the diameter of 7.2 mm is arranged on the central shaft of the disc, and 6 through holes with the diameter of 7.2 mm are uniformly arranged on the circumference which takes the central shaft of the disc as the central diameter of 16 mm; the focusing lens support FLZJ is a ring body with the outer diameter of 30 mm and the inner diameter of 26 mm; the inner hole of the tubular shell GZK is a circular hole with the diameter of 30 mm.

In this embodiment: the output optical fibers of the 7 optical fiber output laser modules are arranged in 7 holes of the columnar optical fiber bracket; 7 collimating lenses are arranged in 7 holes of a disk-shaped collimating lens holder ZZZJ; the focusing lens is arranged in an inner hole of the annular focusing lens bracket FLZJ; the fiber support GXJ is fixed in the inner hole of the tubular shell GZK close to one end, the collimating lens support ZZZJ is fixed in the tubular shell GZK and is adjacent to the fiber support GXJ, and the output fiber end surfaces of the laser output modules on the fiber support correspond to the collimating lenses on the collimating lens support one by one and are positioned near the corresponding focus; the focusing lens support FLZJ is fixed in the tubular housing GZK, abutting the collimating lens support ZZZJ.

In this embodiment, the laser module with the wavelength 1064 outputs the light emitted from the fiber end face, and after passing through the corresponding collimating lens and a common focusing lens, a laser spot with high central power and low edge power is formed on the back focal plane of the focusing lens, and the laser spot is suitable for laser cutting, especially for cutting of high-reflectivity metals. Because the metal surface reflection can be greatly reduced along with the temperature rise according to the properties of the metal, the low-power light spot in the system can preheat a high-power cutting area in advance, the reflectivity of the metal is greatly inhibited, and a laser system is protected.

In this example, a 500 mm focal length focusing lens uses two separate lenses to form an achromatic and spherical lens, where: the lens facing collimated light is a biconvex lens made of quartz glass, the curvature radius of the surface facing collimated light is 118.06, the curvature radius of the other surface is 168.98, and the center thickness is 2 mm; the other lens is a biconcave lens made of F2 glass and spaced 2 mm from the center of the first lens, the surface facing the previous lens has a radius of curvature of 160.54, and the other surface has a radius of curvature of 760.12.

According to the characteristics of the lens, the outer surfaces of the two lenses are cooled by the structure shown in FIGS. 9A to 9C. The lens frame is made of red copper. The lens frame corresponding to the collimating smooth surface of the biconvex lens is a concave surface, the curvature radius of the biconvex lens is 118.06, 6 holes with the diameter of 6.5 are uniformly formed on the circumference with the diameter of 16.02 by taking the vertex as the center, a hole with the diameter of 6.5 is formed at the vertex, and the thickness of the frame at the vertex is 8 mm. The lens frame of the biconcave lens corresponding to the working surface is convex, the radius of curvature 760.12, 6 holes with diameter of 6.3 are uniformly arranged on the circumference with the diameter of 15.79 taking the peak as the center, a hole with diameter of 6.3 is arranged at the peak, and the frame thickness is 8 mm at the peak. The heat dissipation capability of the focusing lens can be greatly improved by adopting the structure.

The composite light spot laser system based on the plurality of optical fiber output laser modules and the processing head utilizing the system can provide various light spots required by laser processing, have the capability of changing the light spot structure in real time, and can meet the requirements of various laser processing. Technically, the thermal problem in the system is better solved, and the system is reliable and has stable characteristics. Because the low-power laser module is directly adopted, the use of a high-power laser is avoided, and meanwhile, the cost of the laser processing system is reduced by using a conventional optical element.

Claims

1. The composite light spot laser system based on the optical fiber output laser modules is characterized by comprising a plurality of optical fiber output laser modules, a plurality of collimating lenses corresponding to the optical fiber output laser modules and a focusing lens; the end face of an output optical fiber of the optical fiber output laser module is positioned near the front focus of the corresponding collimating lens, and the collimating lens at least comprises a lens; the focusing lens at least comprises a lens which is positioned behind the collimating lenses; the output fiber end face of each fiber output laser module is focused by a focusing lens to be near the back focus after passing through a corresponding collimating lens, and the image points are combined to form a composite light spot.

2. The composite speckle laser system based on multiple fiber output laser modules of claim 1, wherein: the optical axes of the collimating lenses are parallel and are arranged in parallel in space; the optical axis of the focusing lens is parallel to the optical axis of the collimating lens; the cross-section of the core of the fiber output laser module output fiber is circular or rectangular in shape.

3. The composite speckle laser system based on multiple fiber output laser modules of claim 1, wherein: by adjusting the position of the fiber output end face of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, images formed by the fiber output end faces of the fiber output laser modules near a focal plane after passing through the corresponding collimating lens and the focusing lens are superposed together to form a single light spot, and the intensity of light spot areas is the same; or the middle power in the spot area is high and the edge power is low.

4. The composite speckle laser system based on multiple fiber output laser modules of claim 1, wherein: by adjusting the position of the fiber output end face of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, images formed by the fiber output end faces of the fiber output laser modules near the focal plane after passing through the corresponding collimating lens and the focusing lens are arranged into a strip-shaped light spot or a rectangular light spot.

5. The composite speckle laser system based on multiple fiber output laser modules of claim 1, wherein: by adjusting the position of the output end face of the optical fiber of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, the output end face of the optical fiber output laser module forms images near the focal plane after passing through the corresponding collimating lens and the focusing lens to form light spots distributed in a plurality of separated areas.

6. The composite speckle laser system based on multiple fiber output laser modules of claim 1, wherein: by adjusting the position of the fiber output end face of the laser module, the shape of the fiber core, the size of the fiber core and the focal length of the corresponding collimating lens, the image formed by the fiber output end face of the fiber output laser module near the focal plane after passing through the corresponding collimating lens and the focusing lens forms light spots arranged along the direction of the optical axis of the lens.

7. The composite speckle laser system based on multiple fiber output laser modules of claim 1, wherein: the position, the fiber core shape, the fiber core size and the focal length of the corresponding collimating lens of the fiber output end surface of the laser module are adjusted, so that the image formed by the fiber output end surface of the fiber output laser module near the focal plane after passing through the corresponding collimating lens and the focusing lens forms a light spot with an annular structure; or forming a light spot consisting of a light spot with an annular structure and a point-shaped light spot positioned at the center of the annular light spot.

8. The composite speckle laser system based on multiple fiber output laser modules of claim 1, wherein: the relative durations of light emission by the fiber output laser modules are the same or different; the power of each fiber output laser module in the relative duration of light emission is the same or different; the relative durations of light emission by the fiber output laser modules are synchronized or unsynchronized.

9. A laser processing head using the composite spot laser system of claim 1, characterized by: the device comprises a plurality of optical fiber output laser modules, a plurality of collimating lenses corresponding to the optical fiber output laser modules, a focusing lens, an optical fiber bracket, a collimating lens bracket, a focusing lens bracket and a tubular shell; the output ends of the output optical fibers of the plurality of optical fiber output laser modules are fixed on the optical fiber bracket; the plurality of collimating lenses are fixed on the collimating lens bracket; the focusing lens is fixed on the focusing lens bracket; the optical fiber support is fixed inside the tubular shell and close to one end, and the output end face of the optical fiber faces the other end of the tubular shell; the collimating lens holder is disposed inside the tubular housing and abuts the fiber optic holder; the focusing lens support is fixed inside the tubular shell and is adjacent to the collimating lens group support; the light emitted by the output optical fiber end faces of the optical fiber output laser modules fixed on the optical fiber support passes through the corresponding collimating lens fixed on the collimating lens group support and then passes through the focusing lens fixed on the focusing lens group support to generate the required composite laser spot.

10. The laser processing head of a composite speckle laser system based on multiple fiber output laser modules as claimed in claim 9, wherein: at least one surface of at least one lens in the focusing lenses is attached to a corresponding lens frame which is processed by good heat conduction materials and has the same surface type on the focusing lens support, and the area corresponding to collimated light on the lens frame is hollowed out to allow corresponding light beams to penetrate through.