CN216979357U

CN216979357U - Optical waveguide for compressing and shaping input light spots generated by optical fiber array

Info

Publication number: CN216979357U
Application number: CN202122606906.6U
Authority: CN
Inventors: 蒋峰; 雷剑; 朱之伟
Original assignee: Suzhou Maxphotonics Co Ltd
Current assignee: Suzhou Maxphotonics Co Ltd
Priority date: 2021-09-14
Filing date: 2021-10-28
Publication date: 2022-07-15
Anticipated expiration: 2031-10-28
Also published as: CN216990328U; CN216817091U; CN115808804A; CN115805359A

Abstract

The embodiment of the utility model provides an optical waveguide for compressing and shaping input light spots generated by an optical fiber array, wherein the optical fiber array is formed by arranging one ends of a plurality of input optical fibers according to a preset shape and/or a preset interval and fixing the input optical fibers through hot melting, glue or an external fixing device, the fiber core diameter of the input optical fibers in the optical fiber array is the same as the fiber core diameter of the non-fixed part of the input optical fibers, the other ends of the input optical fibers are respectively connected with a plurality of laser light sources and used for generating the input light spots, one end of the optical waveguide, which receives the input light spots, is a shaping part with a non-circular cross section and used for compressing and shaping the input light spots, and the end surface of the shaping part is perpendicular to the main plane of an optical axis and has a smooth surface.

Description

Optical waveguide for compressing and shaping input light spots generated by optical fiber array

Technical Field

The utility model relates to the technical field of laser, in particular to an optical waveguide for compressing and shaping input light spots generated by an optical fiber array.

Background

The application field of high-power industrial laser material processing is changing day by day, and compared with the technology that a single laser light source is used for material processing, the multi-laser light source composite high-power laser can greatly expand the laser processing range and greatly improve the laser processing quality. For example, a laser using a novel multi-core ring fiber (ring core fiber) as an optical waveguide is used for low-spatter laser welding, so that different welding application scenes can be adapted, and the welding quality and the welding speed are improved. This type of laser is gradually expanding towards other high quality laser welding applications with the basic goal of replacing high cost semiconductor high quality hybrid welding systems.

At present, the composite laser of multiple lasers may adopt a spatial optical system, such as a polarization or wavelength multiple laser multiplexing system, or an all-fiber signal beam combiner system based on a fiber fused biconical beam combining technology, to combine a plurality of same or different light sources into a single light source system with a complex light spot.

In the scheme based on the space optical system, because a complex space optical system is used for realizing the light spot conversion/multiplexing/coupling from the optical fiber to the optical fiber, the long-term reliability of the system has risks and the cost is high.

The fused biconical approach results in a large loss in the numerical aperture of the light source. In order to compensate the NA deterioration of the tapered combined beam, a high-brightness single transverse mode laser light source and a thinner input optical fiber core diameter are forced to be adopted, so that the maximum power of each input module is limited (generally less than 2000W/module), and complicated design compensation must be made on laser input/optical waveguide and system anti-reflection thereof due to the strong Raman risk of single transverse mode laser, the cost is greatly increased, and the long-term reliability is reduced. And the method can not be well adapted to some complex application scenes (high-reflection processing environments).

Disclosure of Invention

In order to solve the above problems, the embodiment of the present invention discloses an optical waveguide for shaping an input light spot generated by an optical fiber array, wherein one end of the optical waveguide for receiving the input light spot is a shaping portion with a non-circular cross section, which is used for performing compression shaping on the input light spot, and the end surface of the shaping portion is perpendicular to the optical axis main plane and has a flat and smooth surface;

the shaping part is a transparent medium and extends out from one end of the multi-clad optical fiber or is connected together in a welding mode;

the shaping part is a polyhedron symmetrical along a central optical axis;

the shaping part is an optical wedge which is symmetrical along a central optical axis, the wedge comprises at least two inclined planes, and the intersection of the inclined planes and the end face forms two parallel line segments;

the shaping part is an optical wedge which is symmetrical along a central optical axis, the optical wedge comprises four inclined planes, and the intersection of the inclined planes and the end face forms a closed rectangle;

the fiber core of the multi-cladding optical fiber is positioned at the geometric center of the end face, and the input light spot does not exceed the end face range of the optical waveguide;

the fiber core of the multi-cladding optical fiber is aligned with the center of the input light spot, and the preset cladding of the multi-cladding optical fiber is respectively aligned with the periphery of the input light spot;

the shaping part and the optical fiber array are directly connected together in a welding mode;

the optical waveguide is a three-cladding single-core optical fiber, and the fiber core diameter, the inner cladding diameter and the outer cladding diameter of the three-cladding single-core optical fiber are 100 um/300 um/360 um in sequence.

The embodiment of the utility model has the following advantages:

based on the fiber array (ribbon fibers) direct connection technology, the high cost and long-term reliability risk of the spatial optical multiplexing system can be avoided on one hand. On the other hand, the input end is manufactured by adopting a non-optical fiber fused biconical taper technology, so that the complex process of the optical fiber fused biconical taper technology and the special requirements on the input light source caused by the management of the light spot brightness loss can be eliminated. In addition, if the optical fiber fusion tapering technology is used for connection, an optical fiber with a larger diameter needs to be used for tapering, and the large optical fiber is difficult to be compatible with the laser single module technology.

Drawings

Fig. 1 is a block diagram of a laser spot shaping device according to an embodiment of the present invention;

FIG. 2 is a schematic illustration of a ribbon fiber array coupled to a waveguide layer according to an embodiment of the present invention;

FIG. 3A is a schematic illustration of an array of ribbon fibers end-coupled to a wedge-shaped optical waveguide;

FIG. 3B is a schematic diagram of an array of ribbon fibers end-coupled to a rectangular optical waveguide;

FIG. 4 is a schematic view of another angled array of ribbon fibers coupled to a waveguide according to an embodiment of the present invention;

FIG. 5 is a cross-sectional view of a triple-clad optical fiber;

FIG. 6 is a cross-sectional view of a triple-clad optical fiber;

FIG. 7 is a schematic representation of the refractive index of a triple-clad fiber;

FIG. 8 is a cross-sectional view of an energy transmitting fiber;

FIG. 9 is a cross-sectional view of an energy transmitting fiber;

FIG. 10 is a schematic representation of the refractive index of an energy transmitting fiber;

fig. 11 is a flowchart illustrating steps of a method for fabricating a laser spot shaping device according to an embodiment of the present invention;

fig. 12 is a block diagram of a laser processing system according to an embodiment of the present invention;

fig. 13 is a flowchart illustrating steps of a laser processing method according to an embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Referring to fig. 1, a block diagram of a structure of a laser spot shaping device according to an embodiment of the present invention is shown, which may specifically include:

the optical fiber shaping device comprises an input end 10 and a shaping end 11 which are sequentially arranged along a central optical axis, wherein the input end 10 is provided with an optical fiber array consisting of a plurality of input optical fibers which are respectively connected with a plurality of laser light sources, the shaping end 11 is provided with an optical waveguide with a plurality of waveguide layers, fiber cores of the input optical fibers in the optical fiber array are respectively aligned and coupled with the waveguide layers of the optical waveguide, and light beams output by the laser light sources through the optical fiber array are compressed and shaped when passing through the optical waveguide.

In the embodiment of the utility model, the optical fiber array is formed by arranging and fixing the plurality of input optical fibers according to a preset shape, the diameter of the input optical fiber core in the optical fiber array is the same as that of the input optical fiber core of the non-fixed part, and the end face of the fiber core in the optical fiber array is vertical to the optical axis plane.

The optical fiber array may be an array formed by arranging a plurality of optical fibers in parallel into one or more rows, and illustratively, three input optical fibers respectively connected with a plurality of laser light sources may be arranged into one row to form a ribbon optical fiber array; the optical fibers can be arranged in parallel into other preset shapes, for example, seven input optical fibers can be arranged into a polygonal optical fiber array with a two/three-layer structure, and the like. Meanwhile, the fixing mode after the arrangement of the plurality of input optical fibers may include various modes. For example, a plurality of input optical fibers may be fixedly arranged by using an optical fiber clamp, or may be placed in a flat-hole glass tube for fixed arrangement, or may be fixedly arranged by using glue, or other non-fusion tapering methods, such as a plurality of input optical fibers.

The shaping end 11 includes an optical waveguide having a plurality of waveguide layers, different waveguide layers may be different transmission media for shaping input light, and an output end connected to the optical waveguide, where the output end is any one of a multi-clad single fiber or multi-core fiber, and the optical waveguide may be directly a part of the output end, or connected to the output end by welding, soldering, sleeving or mechanical structure.

The optical waveguide can be directly processed by selecting different types of optical fibers, illustratively, a multi-single-core optical fiber or a bare optical fiber head of a multi-core optical fiber can be processed into the optical waveguide, and the other parts are output ends. The single-core optical fiber can be at least one of a three-clad optical fiber and a double-clad energy transmission optical fiber, and the multi-core optical fiber can be an annular optical fiber. In some scenes, the optical waveguide may also be made of a single transparent medium, such as optical quartz glass, and then connected to the output end, i.e., a plurality of single-core optical fibers or a plurality of multi-core optical fibers, by welding or fusing. In the embodiment of the present invention, the corresponding input fiber size may be selected according to the structural size of the optical waveguide. The width of the optical fiber array in the optical fiber arrangement direction is smaller than or equal to the diameter of the outermost layer of the optical waveguide, so that each input optical fiber can be positioned in the range of the corresponding waveguide layer of the optical waveguide. Illustratively, the input fiber adopts double-clad fiber, and the core diameter range is 14um ~100um, then the outmost cladding diameter of every input fiber is less than or equal to 1/3 of the optical waveguide diameter of coupling with it, or is less than outmost cladding diameter minus 20um, just the core NA of input fiber is less than the waveguide layer NA of optical waveguide.

One operable combination of optical fibers is: input fiber core diameter is 14um ~50um, and the cladding diameter is 90 um, the optical waveguide is 360 standard biography energy optic fibre, and the fiber core diameter is 100um, and the surrounding layer diameter is 360 um.

The other fiber combination capable of working is that the diameter of the fiber core of the input fiber is 14 um-50 um, and the diameter of the cladding is 90 um; the optical waveguide is a triple-clad optical fiber, and the diameter of the fiber core, the diameter of the inner cladding and the diameter of the outer cladding are 100 um/300 um/360 um in sequence.

The fiber core diameter of the input optical fiber is 14 um-50 um, and the cladding diameter is 90 um; the optical waveguide is an annular optical fiber, and the diameter of the fiber core and the diameter of the outer fiber core are 100 um/360 um in sequence.

If more waveguide layer optical waveguides are adopted, a greater number of input optical fibers are adopted to form the ribbon fiber array, but the number of input optical fibers or the number of waveguide layer optical waveguides can be selected according to requirements.

The optical fiber array and the optical waveguide may be fusion-spliced, welded, or fixedly connected by a mechanical mechanism, for example, by connecting a ribbon optical fiber array and the optical waveguide by a coupler.

In the embodiment of the utility model, the laser spot shaping device comprises an input end and a shaping end which are sequentially arranged along a central optical axis, the input end is provided with an optical fiber array consisting of a plurality of input optical fibers which are respectively connected with a plurality of laser light sources, the shaping end is provided with an optical waveguide with a plurality of waveguide layers, the fiber cores of the input optical fibers in the optical fiber array are respectively aligned and coupled with the waveguide layers of the optical waveguide, and the light beams output by the laser light sources through the optical fiber array are compressed and shaped when passing through the optical waveguide. The input end and the shaping end can be directly connected based on an array optical fiber connection technology, so that the high cost and the long-term reliability risk of a space optical multiplexing system can be avoided; on the other hand, the input end manufactured by adopting the non-optical fiber fused biconical taper technology can get rid of the complex process of the optical fiber fused biconical taper technology and the special requirements on the input light source for managing the light spot brightness loss.

Meanwhile, if the optical fiber fusion tapering technology is used for connection, an optical fiber with a larger diameter needs to be used for tapering, and the large optical fiber is difficult to be compatible with the laser single module technology. Due to the reduction of the requirement on an input light source, a universal high-power single-module multimode laser light source in the current market can be directly utilized, a few multimode laser modules (2, 3 laser light sources of 4000W) are used for compounding high-power compound laser, compared with the prior art that 6-8 laser modules are required by a fused biconical taper technology to realize 6000W overlapped 6000W compound laser, the cost of the compound laser is greatly reduced, and the system control is simplified.

In addition, the embodiment of the utility model not only can use the traditional multi-core optical fiber as the optical waveguide, but also can use the three-clad optical fiber which is commonly used in the non-composite optical system and the standard 360 energy transmission optical fiber as the optical waveguide, thereby greatly reducing the cost and facilitating the laser maintenance and updating of users.

In the embodiment of the utility model, the optical waveguide is a transparent medium which is symmetrically distributed along a central optical axis and has a non-circular cross section, and the end face of the optical waveguide is perpendicular to the plane of the optical axis.

Illustratively, the optical waveguide may be in the shape of a wedge symmetric along a central optical axis, or may be in the shape of other polyhedrons axially symmetric, such as a cube or a cuboid.

Illustratively, a multi-cladding single-core fiber or a multi-core fiber such as a ring fiber can be used to make an optical wedge fiber, and the optical wedge fiber is directly coupled with a ribbon fiber array, wherein the end face of the optical wedge is perpendicular to the plane of the optical axis, the shape of the optical wedge is close to the shape of the end face of the ribbon fiber array coupled with the optical wedge, the optical wedge is nearly elliptical, an inclined plane extends along the upper side and the lower side of the end face of the optical wedge, the intersection of the inclined plane and the end face is two line segments parallel to the plane of the optical axis, and the shortest distance between the two line segments is greater than or equal to the diameter of a fiber core in the ribbon fiber array, so that an input light spot does not exceed the end face range of the optical waveguide.

Referring to fig. 2, a schematic diagram of a ribbon fiber array and a wedge fiber according to an embodiment of the present invention is shown. In fig. 2, viewed at an angle aligned parallel to the plurality of input fibers, i.e. parallel to the plane of the optical axis, a single input fiber is observed, and the other input fibers are understood to be blocked by the input fibers that can be observed. In effect, the end faces of each input fiber in the fiber array are aligned with the end faces of the wedge fibers.

After laser output from the fiber core of the input optical fiber is incident into the optical waveguide, a part of the laser is reflected back into the optical waveguide by the end face of the optical wedge, which is equivalent to increase the receiving angle of the optical waveguide, so that laser with more incident angles can be transmitted in the optical waveguide, the light collecting capacity of the optical waveguide can be improved, the light beam is shaped, and the compression of the numerical aperture NA of the incident light is realized.

In the embodiment of the present invention, the cross section of the optical waveguide is a non-circular interface distributed symmetrically along the optical axis, and the non-circular interface may be a symmetrical shape composed of parallel line segments and circular arcs, for example, in addition to the optical wedge shape mentioned in the above embodiment; the optical waveguide can also be a regular polygon formed by line segments, and can also be a cuboid shape with a rectangular cross section which is symmetrically distributed along the optical axis, and the cuboid optical waveguide has better light collecting capability in practical application. Referring to fig. 3A, a schematic diagram of the coupling of the ribbon fiber array and the end face of the wedge-shaped optical waveguide is shown, and the cross section of the optical waveguide is a symmetrical shape composed of parallel line segments and circular arcs; referring to fig. 3B, a schematic diagram of the end-face coupling of the ribbon fiber array and the rectangular optical waveguide is shown, wherein the cross section of the optical waveguide is rectangular.

The cross section of the optical waveguide is processed into an ellipse or a polygon which is symmetrically distributed along the central optical axis, so that the center of the optical waveguide is positioned at the geometric center, and laser which is injected into the optical waveguide can be symmetrically reflected in all directions. Referring to fig. 4, a schematic diagram of another angle of the connection between the ribbon fiber array and the waveguide layer according to the embodiment of the present invention is shown, wherein the end face of the optical waveguide is a nearly elliptical shape symmetrically distributed along the optical axis, so as to better couple with the end face of the input fiber in the array fiber. In fig. 4, the plurality of input optical fibers are viewed at an angle perpendicular to the arrangement of the plurality of input optical fibers. The number of the input optical fibers is three, and the input optical fibers positioned in the middle are aligned with the central waveguide layer of the optical waveguide; the input optical fibers on both sides are aligned with the waveguide layer on the outer side of the optical waveguide.

In the embodiment of the utility model, because the small optical fibers are adopted in the optical fiber array, the diameter of the input optical fiber is smaller than that of the waveguide layer, and the waveguide layer of the optical waveguide and the input optical fiber core in the ribbon optical fiber array can be in center alignment and/or eccentric alignment.

In the case of center alignment, the laser light transmitted from the input fiber core in the ribbon fiber array can be transmitted all the way into the corresponding waveguide layer, so that the output laser power is maximized.

Under the condition of eccentric alignment, the laser transmitted from the input optical fiber core in the ribbon fiber array can be transmitted to the corresponding waveguide layer completely or transmitted to at least two corresponding waveguide layers, and the power and the spot shape of the output laser can be adjusted by adjusting the eccentric degree.

Referring to fig. 5, which is a cross-sectional view of a triple-clad optical fiber, and fig. 6, which is a cross-sectional view of a triple-clad optical fiber, the triple-clad optical fiber includes a core, a first cladding (inner cladding), which may be a fused silica inner cladding, and a second cladding (outer cladding), which may be an F-doped silica cladding, and the thickness of the first cladding is greater than that of the second cladding. Illustratively, the core diameter, the inner cladding diameter, and the outer cladding diameter are sequentially 100 um/300 um/360 um. Fig. 7 is a schematic diagram showing refractive indexes of a triple-clad optical fiber, which transmits laser light in a core and an inner cladding, wherein the refractive indexes of the core, the first cladding and the second cladding are sequentially decreased. Under the condition that the three-clad optical fiber is connected with the waveguide layer, the three-clad optical fiber can achieve the effect of less than 0.12NA, and the three-clad optical fiber is low in cost, so that the cost of a laser spot shaping device can be reduced.

Referring to fig. 8, which is a cross-sectional view of an energy-transmitting optical fiber, and fig. 9, which is a cross-sectional view of an energy-transmitting optical fiber, the energy-transmitting optical fiber includes a core, a first cladding (inner cladding), which may be an F-doped silica cladding, and a second cladding (outer cladding), which may be a fused silica cladding, and the thickness of the first cladding is smaller than that of the second cladding. Illustratively, the core diameter is 100um and the outer cladding diameter is 360 um. Fig. 10 is a schematic refractive index diagram of an energy transmitting fiber that transmits laser light in a core and a second cladding, which may have substantially the same refractive index, the first cladding having a lower refractive index than the core and the second cladding. In the case of connecting the energy transmission optical fiber and the waveguide layer, the energy transmission optical fiber can achieve the effect of less than 0.22 NA.

Referring to fig. 11, a flowchart illustrating steps of a method for manufacturing a laser spot shaping device according to an embodiment of the present invention is shown, where the method specifically includes the following steps:

step 1101, acquiring a plurality of input optical fibers respectively connected with a plurality of laser light sources, arranging the input optical fibers in parallel according to a preset shape, and fixing to form an optical fiber array.

In an alternative embodiment of the present invention, the step 1101 may comprise the following sub-steps:

and a substep S11 of arranging and fixing the input optical fibers into a preset shape by using an optical fiber clamp, keeping a preset gap between fiber cores of the input optical fibers, and fixing the input optical fibers by hot melting, glue or an external fixing device to form an optical fiber array, wherein the diameter of the fiber core in the optical fiber array is the same as that of the fiber core of the non-fixed part of the input optical fiber.

And a substep S12, cutting the optical fiber array by using optical fiber cutting equipment to obtain a smooth optical fiber array end face, wherein the fiber core end face in the optical fiber array is perpendicular to the optical axis plane.

The fiber clamp can include two holders that can mutually support, and the holder has the recess, and optic fibre can be held in the recess, and the interval of recess can be made according to actual need to make optic fibre arrange into one row and fixed according to predetermineeing the clearance, then can adopt standard banding optical fiber cutting equipment to cut fiber array, obtain smooth fiber array terminal surface. For example, the predetermined gap may be zero, i.e., the coating layers of the input optical fibers are tightly connected, and there is a gap between the bare optical fibers (optical fibers excluding the coating layers).

In another alternative embodiment of the present invention, the step 1101 may comprise the following sub-steps:

the substep S21, closely arranging the input optical fiber cores into a preset shape, and placing the preset shape into a deformation hole capillary glass tube;

a substep S22, welding the input optical fiber cores and the glass tube into a whole to form a fixed optical fiber array, wherein the diameters of the cores in the optical fiber array are the same as the diameters of the cores in the non-fixed part of the input optical fibers;

specifically, a plurality of input optical fiber cores and a glass tube can be welded and connected into a whole by using a fire grinding process to form a fixed optical fiber array.

And a substep S23 of cutting the optical fiber array by using optical fiber cutting equipment to obtain a flat and smooth optical fiber array end face, wherein the fiber core end face in the optical fiber array is perpendicular to the optical axis plane.

Referring to FIG. 11, an embodiment of the present invention is illustrated in which a glass tube is capillary-shaped through a deformation hole to form a ribbon fiber array. Specifically, a flat hole glass tube can be adopted, three input optical fibers are placed in the glass tube, the outer surfaces of the three input optical fibers are connected into a whole in a fusion welding mode through a fire grinding process, the bare optical fibers are closely arranged in a row at the moment, a fiber cutting knife can be used for processing the bare optical fibers to obtain a flat optical fiber array end face, and the end face is perpendicular to the optical axis plane.

Step 1102 includes obtaining an optical waveguide having a plurality of waveguide layers.

Illustratively, a single core optical fiber or a multi-core optical fiber may be obtained as the optical waveguide, wherein the single core optical fiber may be at least one of a triple-clad optical fiber and a double-clad energy transmitting optical fiber.

In an optional embodiment of the present invention, the method may further include: polishing and grinding the optical waveguide along two sides of the end face to form a geometrical shape which is symmetrically distributed along a central optical axis and has a non-circular cross section; and polishing the end face of the optical waveguide or cutting the planar optical fiber to enable the end face of the optical waveguide to be flat and smooth and to be vertical to the plane of the optical axis.

In one example, the optical waveguide may be processed into a wedge shape, where the end surface of the wedge is a vertical surface and the two sides are inclined surfaces. Specifically, the end face of the optical waveguide may be machined into a vertical plane, and then two inclined planes are machined outwards from the end face to the center of the optical waveguide, the intersection of the inclined planes and the end cap is two symmetrical parallel line segments, and the distance between the two line segments and the center of the optical waveguide is greater than the radius of the fiber core of the input optical fiber. For example, the end face may be polished on both sides or fine machined with a femtosecond laser, a CO2 laser, to a bevel such that the end face remains vertical in the middle and symmetrical bevels on both sides. The optical wedge end face is axisymmetric in the horizontal direction and the vertical direction, and the fiber core can be ensured to be positioned in the geometric center of the optical wedge end face. The end face of the optical wedge is a nearly elliptical surface and is also polished or processed by planar fiber cutting (planar dissociation).

The wedge end face of the optical waveguide is a nearly elliptical surface as viewed from the laser incident direction, so that the wedge end face is an end face that is axisymmetric in both horizontal and vertical directions. In practice, the optical wedge may also be processed into other axisymmetric shapes, such as a cube, which is not limited by the embodiment of the present invention.

By processing the end face of the optical waveguide into an optical wedge or other shapes, the laser transmitted in each input optical fiber is refracted according to a specific direction when entering the optical waveguide, so that the NA compression of an input light beam is realized, the output NA is reduced, the filling rate of optical fiber multiplexing is improved, the brightness of an output light source is finally improved, and the requirement on the brightness of the input light source is also reduced; meanwhile, the design of processing the optical fiber into the optical wedge or other shapes can amplify the NA of the reverse light and extrude the reverse light out of the optical fiber, thereby greatly improving the high-reflection resistance of the device/system.

On the other hand, the spatial intensity distribution of the laser beam is gaussian, i.e. gaussian beam, while in many laser technology applications, the laser intensity is expected to be uniformly distributed, and by compressing and shaping the light spot, the output optical fiber can be completely compatible with the prior art application.

By polishing the end face of the optical waveguide or cutting the planar optical fiber, laser leakage caused by rough and defective end face can be avoided.

Step 1103, respectively aligning and coupling the cores of the plurality of input optical fibers in the optical fiber array with the plurality of waveguide layers of the optical waveguide.

Illustratively, a power monitoring fusion process may be used to obtain the optimal alignment point. The power of laser output by each waveguide layer of the optical waveguide can be detected, and whether the alignment is carried out or not can be judged according to the laser power of each waveguide layer.

Illustratively, the input end and the optical waveguide may be pre-sized with sufficient tolerances to facilitate alignment of the two ends.

In an alternative embodiment of the present invention, the step 1103 may comprise the following sub-steps:

sub-step S31, coupling and aligning each core in the optical fiber array with the middle portion of the corresponding waveguide layer of the optical waveguide, so that the output single laser beam keeps transmitting in the corresponding waveguide layer;

in the case where the cores of the input fibers in the ribbon fiber array are aligned in coupling with the middle portions of the respective waveguide layers of the optical waveguide, the laser light transmitted from the cores of the input fibers in the ribbon fiber array can be transmitted entirely into the respective waveguide layers, so that the output laser power is maximized.

Or, in sub-step S32, at least one core in the optical fiber array is coupled and aligned with a non-intermediate portion of a corresponding waveguide layer of the optical waveguide, so that the single laser output by the input optical fiber is transmitted in at least two waveguide layers.

Under the condition that the input optical fiber core in the ribbon optical fiber array is coupled and aligned with the non-middle part of the corresponding waveguide layer of the optical waveguide, the laser transmitted from the input optical fiber core in the ribbon optical fiber array can be partially transmitted into the corresponding waveguide layer, and the power and the spot shape of the output laser can be adjusted by adjusting the eccentricity degree. And 1104, connecting the optical fiber array and the optical waveguide together through welding, soldering or a mechanical structure.

The ribbon fiber array and the optical waveguide can be directly welded or soldered together, or the ribbon fiber array and the optical waveguide can be fixedly connected through a mechanical mechanism, for example, the input end and the shaping end are connected through a coupler.

For example, a ribbon fusion splicer may be used to fuse the ribbon fiber array to the optical waveguide. Special welding equipment such as flame, laser or standard welding machines can also be used to directly weld with customized welding parameters. The optical fiber fused tapering process is completely abandoned, and the phenomena that the quality of light spots irradiated by the fused tapering process to the optical fiber is poor or the optical fiber is polluted and generates heat due to light leakage of the optical fiber are reduced to the maximum extent.

In the embodiment of the utility model, a plurality of input optical fibers respectively connected with a plurality of laser light sources can be obtained, and the input optical fibers are arranged in parallel according to a preset shape and then are fixed to form an optical fiber array; obtaining an optical waveguide with a plurality of waveguide layers; respectively aligning and coupling fiber cores of a plurality of input fibers in the fiber array with a plurality of waveguide layers of the optical waveguide; the optical fiber array and the optical waveguide are connected together through welding, soldering or mechanical structure. The laser beams output from the plurality of laser light sources are transmitted to the optical waveguide through the input optical fiber, and the optical waveguide shapes the light beams to output the composite laser beam. The input end and the shaping end can be directly connected based on array fibers (ribbon fibers), so that the high cost and long-term reliability risk of the spatial optical multiplexing system can be avoided on one hand. On the other hand, the input end is manufactured by adopting a non-optical fiber fused biconical taper technology, so that the complex process of the optical fiber fused biconical taper technology and the special requirements on the input light source caused by the management of the light spot brightness loss can be eliminated. In addition, if the optical fiber fusion tapering technique is used for connection, an optical fiber with a larger diameter is required for tapering, and the large optical fiber is difficult to be compatible with the laser single module technique.

Referring to fig. 12, a block diagram of a laser processing system according to an embodiment of the present invention is further disclosed, where the laser processing system may include: a plurality of laser modules 120, a laser spot shaping device 121, and a power control module 122; the laser beams output by the plurality of laser modules 120 realize spot shaping when passing through the laser spot shaping device 121, and output a composite spot having a central spot and at least one peripheral spot; the power control module 122 is connected to the laser modules 120 and configured to control the power of the laser modules 120 to be adjustable within a preset range, so that the central light spot and the peripheral light spots form a composite light spot output with different energy ratio profiles.

The laser spot shaping device 121 may refer to the foregoing embodiments, and this embodiment is not described in detail herein.

Referring to fig. 13, an embodiment of the present invention further discloses a laser processing method, including:

step 1301, outputting a plurality of light beams arranged according to a preset shape;

step 1302, performing compression shaping on the plurality of light beams, and outputting a composite light spot having a central light spot and at least one peripheral light spot;

step 1303, controlling the power values of the multiple light beams to be adjustable within a preset range, so that the central light spot and the peripheral light spots of the composite light spot form outlines with different energy ratios;

in step 1301, referring to the foregoing embodiment, the multiple light beams may be output in parallel in a strip shape, or may be output in combination of light beams of other shapes.

In step 1302, when at least one of the plurality of light beams enters the shaping portion of the optical waveguide, the light beam is reflected in the optical waveguide for multiple times, and finally the compressed shaping output of the composite light spot is realized, wherein the central light spot is located at the center of the peripheral light spots, the central light spots are distributed in a gaussian or flat top manner, and the peripheral light spots are distributed in a flat top manner.

In step 1303, the power of the central and peripheral annular light spots is adjustable within a certain range by matching with a unique electric control technology;

and 1304, adjusting the power value of the first light beam to adjust the energy distribution of the light spot irradiated by the first light beam to the workpiece and/or adjusting the power value of the second light beam to adjust the energy distribution of the light spot irradiated by the second light beam to the workpiece according to the input material, the processing requirement and the processing environment parameters of the workpiece to be processed, and performing laser cladding, cutting or welding.

According to the process provided by the embodiment of the utility model, a plurality of input optical fibers connected with a plurality of laser light sources respectively are adopted to form a ribbon optical fiber array; adopting a multi-cladding optical fiber as an optical waveguide, and processing the end face of the optical waveguide into an optical wedge end face; aligning the ribbon fiber array with the vertical plane of the optical waveguide, so that the fiber cores of all input fibers of the ribbon fiber array are respectively coupled into the waveguide layer of the optical waveguide from the vertical plane; after the coupling is completed, the ribbon fiber array is fused with the optical waveguide, so that the laser output by the plurality of laser light sources through the input optical fiber passes through the optical waveguide to form composite laser. By utilizing the process of the embodiment of the utility model, the fiber core of the optical waveguide can output Gaussian spots or flat-top spots, and the preset cladding outputs annular flat-top spots.

It should be noted that, for simplicity of description, the method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present invention is not limited by the illustrated order of acts, as some steps may occur in other orders or concurrently in accordance with the embodiments of the present invention. Further, those skilled in the art will appreciate that the embodiments described in the specification are presently preferred and that no particular act is required to implement the utility model.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus, or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Embodiments of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the utility model. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing terminal to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing terminal to cause a series of operational steps to be performed on the computer or other programmable terminal to produce a computer implemented process such that the instructions which execute on the computer or other programmable terminal provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the utility model.

Finally, it should also be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. The optical waveguide for compressing and shaping the input light spots generated by the optical fiber array is characterized in that one end, at which the input light spots are received, of the optical waveguide is a shaping part with a non-circular cross section and used for compressing and shaping the input light spots, and the end face of the shaping part is perpendicular to the main plane of an optical axis and is flat and smooth in surface.

2. The optical waveguide of claim 1, wherein the shaping portion is a transparent medium extending from one end of the multi-clad optical fiber or is welded, fused, sleeved, or mechanically connected together.

3. The optical waveguide of claim 1, wherein the shaping portion is a polyhedron that is symmetrical about a central optical axis.

4. The optical waveguide of claim 3, wherein the shaping portion is a wedge symmetric about a central optical axis, the wedge comprising at least two inclined surfaces, the intersection of the inclined surfaces with the end surfaces forming two parallel line segments.

5. The optical waveguide of claim 3, wherein the shaping portion is a wedge symmetric about a central optical axis, the wedge including four inclined surfaces, the intersection of the inclined surfaces with the end surfaces forming a closed rectangle.

6. The optical waveguide of claim 2, wherein the core of the multi-clad fiber is located at the geometric center of the end face, and the input spot does not exceed the end face extent of the optical waveguide.

7. The optical waveguide of claim 6, wherein the core of the multi-clad fiber is aligned with the center of the input spot, and the pre-clad of the multi-clad fiber is aligned with the periphery of the input spot.

8. The optical waveguide of claim 1, wherein the shaping portion of the optical waveguide and the array of optical fibers are directly connected together by fusion splicing, soldering, or mechanical means.

9. The optical waveguide of any one of claims 1 to 8, wherein the optical waveguide is a three-clad single-core optical fiber, and the core diameter, the inner cladding diameter and the outer cladding diameter of the three-clad single-core optical fiber are 100 um/300 um/360 um in sequence.