RU2632745C2 - Multi-beam laser radiation source and device for handling materials with its use - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: multiple-beam source consists of a generator and a multi-channel amplifier. Radiation generator comes to the input of the amplifier via the Extender, and then hardened individual fragments of a wide beam of the active element, consisting of laser plates located successively in several parallel ranges. Each plate contains elongated along the longitudinal axis of the plate at the heart of the active material and surrounding it with the side of a dormant shell. The space between all the plates is filled with heat sink elements. The pump radiation is fed through the free narrow faces of the plates. Treated material is placed on the base surface, conventionally divided into sectors according to the number of laser beams. Scanning heads installed over one of the vertices of each sector at an altitude determined by the formula h=d/tgα, where d is the diagonal length of the sector, α - maximum scan angle. To compensate alignment errors of laser heads used rigid frame with a square grid sensors.

EFFECT: invention allows the simultaneous use of a large number of powerful laser beams to speed the processing of large volume products.

5 cl, 14 dwg

Description

Technical field

This invention relates to the field of laser processing of materials, including laser cutting, welding, surfacing and selective sintering of large parts or when processing a large number of products on a single laser complex.

State of the art

High-power lasers have many applications in which an intense beam of coherent light is focused on a substrate to process its surface or sinter a substrate laid on a substrate, or acts on other targets. Often high-power laser systems use a master oscillator and a power amplifier, which brings the energy parameters of the laser beam generated by the master oscillator to the level required by a particular application.

In some laser applications, it is desirable to simultaneously direct multiple laser beams into a single target or process multiple targets simultaneously. For example, in laser microprocessing, this may be advantageous for drilling small and precise holes in parallel at several places in order to speed up the processing. One possible way to produce multiple laser beams is to divide the laser beam from a powerful source into several beams with a proportional decrease in the power of each beam compared to the original beam. A device of this type is described in patent application [1]. It is an analogue of the invention. The disadvantage of the analogue is the inability to obtain a large number of rays due to a sharp decrease in their power when dividing the original laser beam.

An alternative to splitting radiation in a laser system with a single power amplifier is to separate the output radiation of the master oscillator and use several power amplifiers. This approach is implemented in the laser device described in the patent [2] and selected as a prototype of the present invention. The disadvantage of the prototype is that each amplification channel is equipped with its own pumping and cooling systems, which increases the size and cost of the multi-beam laser system and does not allow the number of beams to reach several tens or hundreds of units in a device with reasonable dimensions. Another disadvantage of the prototype is the inevitable decrease in the quality of the obtained laser beams relative to the radiation quality of the master oscillator due to the influence of thermal and diffraction effects, which limits the possibility of sharp focusing of the beam on distant targets.

Thus, there is a need for a multi-beam laser device in which these disadvantages are overcome.

SUMMARY OF THE INVENTION

The disadvantages associated with the prior art are overcome by the embodiment of the present invention by using a large number of parallel power amplification channels with common pump and cooling systems for all parallel channels. This ensures high quality of the generated radiation beams due to the expansion of the radiation of the master oscillator, which is accompanied by a significant reduction in the divergence of the laser beam. Further parallel amplification of individual fragments of a wide beam occurs in a multichannel amplifier with specially adopted measures to reduce the influence of thermal and diffraction distortions of the wavefront. For this, a large number of crossed thin plates with an active core are used, having a cross-sectional size approximately equal to the cross-sectional size of the amplified beam in each channel. The crossed sequential arrangement of sections of the thin amplifying medium provides the minimum astigmatism created by temperature gradients, compared with other profiles, due to the best conditions for heat removal and the symmetrical action of the thermal lenses inevitably arising in powerful devices and the orthogonal orientation of the axes of the heat-induced birefringence in the active core. The decrease in the influence of diffraction effects is provided by the concentration of amplification in the optically homogeneous part of the plates located at a distance from the outer longitudinal surfaces of the plates, on which the refractive index of the medium changes sharply, causing diffraction distortions of the wave front. Electromagnetic waves appearing due to diffraction propagate at an angle to the axis of the amplification channel and, due to the crossed arrangement of the plates, can be quickly output through inactive parts of the end surfaces that do not have optical contact with the end surfaces of other plates, practically without amplification. In the same way, the amplification of the main part of the waveguide and other unnecessary transverse modes, as well as spontaneous and spurious emissions, is blocked. A much smaller part of such types of harmful radiation falling into the axial region of the active medium and passing along its entire length is suppressed due to the sufficiently high power density of the continuous radiation generated by the master oscillator. The dominance of useful radiation is ensured by the proportionality of the probability of the forced study of the radiation power density, which propagates in a pumped medium [8].

These advantages make it possible to scale the power of laser systems, using a large number of crossed active core plates, over a wider range than conventional analogues.

According to the invention, the task of obtaining tens and hundreds of units of high-power laser beams with high radiation quality is solved in a multi-beam laser radiation source containing a master oscillator and a multichannel amplifier, due to the fact that the output radiation of the master oscillator is fed to the input of a multichannel amplifier through an expander that reduces the divergence and increasing the cross section of the laser beam to the size of the input aperture of a multichannel amplifier with subsequent amplification of individual fragments widely beam using an active element consisting of a large number of laser plates arranged in series in several parallel rows. Each plate has the shape of a rectangular parallelepiped and contains an active material core extended along the longitudinal axis of the plate and an inactive shell of optical material surrounding it on the sides with the same or close refractive index, while the transverse dimension of the core is less than the thickness of the plate. In each row, the longitudinal axes of adjacent plates are aligned and form the optical axis of the gain channel. The rows are arranged compactly, with the same pitch in the vertical and horizontal directions, with wide faces, for example, even plates in all rows, located horizontally, and wide faces of alternative plates, located vertically and narrow longitudinal faces facing each other in adjacent rows, connected between with an optical contact. The space between all the plates is filled with heat-removing elements, and the pump radiation is created by the lines of laser diodes and is fed through the free narrow edges of the plates. Thanks to the proposed placement of active layers in parallel rows, free access of the heat sink to the wide surfaces of all plates is ensured, which allows efficient removal of large heat fluxes at low temperature gradients.

To reduce the effect of reflections from free narrow faces perpendicular to the optical axis, in each row, for example, even plates can have a wide pair of faces in the form of a parallelogram, while alternative plates should have a longitudinal narrow pair of faces in the form of a parallelogram, the corresponding angles of these parallelograms should be equal, and the remaining faces of the plates should be rectangular.

To compensate for the dispersion of group velocities (GVD) during amplification of ultrashort pulses, all or part of the plates can have on each narrow face perpendicular to the longitudinal axis of the active layer a transparent diffraction grating with a symmetrical line profile that deflects the incident radiation in a plane perpendicular to the wide faces of the plate, and ensures the propagation of radiation along the optical axis of the active core in the form of symmetrical waveguide modes due to total internal reflection from wide faces. Compensation of the GVD is ensured by a larger deviation angle of the long-wavelength part of the radiation spectrum, which leads to an increase in the optical path length of this part of the spectrum, compared with the short-wavelength part, and to a decrease in the duration of the amplified radiation pulse.

Using a multi-beam source with high quality laser beams allows us to solve the problem of increasing the number of simultaneously processed material points on the base surface to tens and hundreds of units with the possibility of processing each point simultaneously with several beams. To do this, in a setup containing a bed with a square or rectangular base surface, a multipath laser source and scanning laser heads, the output windows of these heads are installed above the vertices of the conditional square or rectangular sectors of the base surface according to the number of laser source rays. The output windows are placed at a height determined by the formula h = d / tgα, where d is the diagonal length of the sector, α is the maximum scanning angle. With this installation, the scanning area of the laser heads covers four sectors, excluding the heads mounted above the boundary of the base surface, which allows the following processing options for the material on the base surface to be realized:

- parallel processing with a single beam in all sectors, as shown in FIG. 1 (shaded simultaneously processed sectors);

- parallel processing of two beams in part of the sectors, as shown in FIG. 2;

- parallel processing of three beams in part of the sectors, as shown in FIG. 3;

- parallel processing with four beams in part of the sectors, as shown in FIG. four.

To correct errors in alignment of laser heads between the scanning heads and the base surface, a rigid frame can be installed with sensors of the coordinate grid, allowing software to compensate for inaccuracies in the alignment of laser scanning heads.

Thus, in a compact installation for laser processing of materials, the simultaneous use of a large number of laser beams is ensured, which makes it possible to repeatedly increase the productivity of an installation that allows the manufacture of large volume products or the simultaneous manufacture of a large number of products in one installation with the same or different modes of exposure to material.

Brief Description of the Drawings

In FIG. 1 shows sectors of the base surface simultaneously processed by a single laser beam.

In FIG. 2 shows sectors of the base surface simultaneously processed by two laser beams.

In FIG. Figure 3 shows sectors of the base surface simultaneously processed by three laser beams.

In FIG. 4 shows sectors of the base surface simultaneously processed by four laser beams.

In FIG. 5 shows laser plates with an active core having a different cross-sectional profile.

In FIG. 6 shows a multipath source of laser radiation.

In FIG. 7 shows a multi-beam laser amplifier.

In FIG. Figure 8 shows the placement of composite laser plates in a multipath amplifier.

In FIG. 9 shows one row of laser plates with one pair of faces in the shape of a parallelogram.

In FIG. 10 shows one row of laser plates with an increasing core size.

In FIG. 11 shows a plate with a diffraction grating at the narrow end faces of the laser plates.

In FIG. 12 shows a device for processing materials using a multi-beam laser source.

In FIG. 13 shows a device for processing materials with grid sensors.

In FIG. 14 shows a dual laser scanning head.

Description of symbols

one: master oscillator 2: output radiation beam of the master oscillator 3: laser expander four: laser beam expander output beam 5: array of output beams of a multipath source of laser radiation 6: laser scanner output beam 7: multipath laser amplifier 8: reflective prism 9: laser scanner 10: laser plate eleven: active core 12: series of laser plates in series 13: longitudinal narrow face fourteen: wide line fifteen: diffraction grating 21: heat sink plate 22: coolant manifold 23: fitting 24: through holes for pumping coolant 25: input / output diaphragm of a multipath laser amplifier. 31: laser diode line 32: array of laser diode lines 91: scan area 92: mirror one hundred: bed 101: base surface 102: grid of square or rectangular sectors 103: coordinate frame 104: grid sensors.

The implementation of the invention

The present invention provides an improved multipath source of laser radiation, consisting of a master oscillator, a laser beam expander and a multi-channel amplifier with common pumping and cooling systems for all parallel channels, using a large number of composite plates consisting of an inactive optical material and an active core extended into it along the axis of the plate. These plates are assembled in one or more parallel rows to obtain a large number of intense laser beams with low divergence and with high and ultrahigh power.

The present invention makes it possible to obtain tens and hundreds of powerful laser beams with low divergence in a compact design.

The following is a definition of the terms used in this document.

The term composite laser plate refers to an element made of an inactive optical material, transparent to the amplified radiation and the pump radiation, with an active core embedded in it with a deep optical contact.

The term active core refers to the elongated along the longitudinal axis of the part of the composite laser plate, which is made of an optical material consisting of a crystalline or amorphous matrix doped with suitable ions that are excited by pumping. Preferred materials are:

yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), gadolinium-

scandium gallium garnet (GSGG), yttrium-lithium fluoride (YLF), yttrium vanadate,

phosphate laser glass, silicate laser glass, sapphire and others.

Suitable dopants for these laser generating media include, but are not limited to, Ti, Cu, Co, Ni, Cr, Ce, Pr, Nd, Sm, Eu, Yb, Ho, Dy and Tm.

The term inactive optical material refers to a material that does not contain dopants, preferably the same as the material of the active core, or to a material with the same or similar value of the refractive index, unless its value is specified otherwise.

The longitudinal narrow faces of the plate are the faces that are parallel to the longitudinal axis of the active core. The narrow end faces of the plate are the faces through which the longitudinal axis of the active core passes.

When implementing the invention, the cross-sectional size of the active core should be less than the thickness of the plate. The cross sectional shape of the active midpoint may be round, ellipsoidal, rectangular, square, and the like, as shown in FIG. 5. Methods of manufacturing such plates are disclosed, for example, in patents [3 ... 6].

In one embodiment of the multi-beam laser source shown in FIG. 6, the multi-beam laser source consists of a master oscillator 1, a laser beam expander 2, and a multi-channel amplifier 7. The multi-channel amplifier 7 shown in FIG. 7, includes several arrays of lines of laser pump diodes 32 with a cooling system and drivers for the power supply system (not shown in FIGS. 6 and 7), elements of the heat sink system 21, 22, 23 and a multi-channel active element shown in FIG. 8. The active element is a set of parallel-mounted rows 12, consisting of a sequence of laser plates 10, with coaxial active cores 11. The wide edges of adjacent plates in each row are rotated 90 degrees relative to each other.

Multipath laser source in this embodiment works as follows.

The master laser radiation generator 1 forms a thin, slightly diverging beam of electromagnetic radiation 2 with a good quality indicator in the range of M2 = 1.5 ... 2 mm mrad. This radiation enters the input of the expander 3. A wide beam of radiation 4 from the output of the expander 3 is divided into fragments, passing through the diaphragms 25 in the first collector of the coolant 22, which are separately amplified in the multi-channel active element. The amplified radiation beams 5 are output through the diaphragms 25 in the second coolant manifold 22. All wide faces of the composite laser plates 10 constituting the active element are in thermal contact with the heat-removing elements 21 having through holes 24 for pumping the coolant. The cooling liquid flows under pressure into the inlet manifold 22 through the nozzle 23 and is pumped through all coaxial openings 24 in the heat-removing elements 21 to the outlet manifold 22, from where the heated liquid through the nozzle 23 is discharged to the chiller for cooling and reuse or utilized. The active medium is pumped using a line of laser diodes 31, assembled into arrays 32. The pump radiation enters the multichannel active medium through free longitudinal narrow faces of the plates 10 and, thanks to the total internal reflection, propagates, gradually being absorbed by the material of the active core 11, through several plates 10, in which the longitudinal narrow faces have optical contact.

To obtain high-quality radiation at the output of a multi-beam laser source, the expander 3 must ensure at its output that the quality of the radiation beam 4 is maintained at a level close to the quality of the output radiation beam 2 of the master oscillator. In this case, the divergence of the radiation at the input of the multichannel amplifier compared with the divergence of radiation at the output of the master oscillator decreases in proportion to the ratio of the beam cross sections at the output 4 and input 2 of the expander 3. This means that the radiation from the plane of each of the parallel channels of the amplifier 7 is almost flat wave front.

To obtain high-quality radiation at the output of a multipath laser source, you must:

- minimize the influence of thermo-optical effects in the amplifier;

- reduce the effect of diffraction effects;

- eliminate the possibility of propagation of waveguide and other unnecessary transverse modes;

- eliminate amplified spontaneous and spurious emissions.

Thermo-optical effects are manifested mainly in the form of a transverse gradient of the refractive index and induced birefringence. The transverse gradient of the refractive index is caused by an uneven temperature field created in the process of heat removal from active layers, which are heated during pumping. When the output power of each beam 5 is of the order of 300 W, the total length of the active layers 10 in one gain channel is about 80 cm and the coefficient of use of the pump energy is about 0.7, a power equal to about 1.6 W should be dissipated in one linear centimeter of the active layer. When using yttrium-aluminum garnet with a thermal conductivity of 0.14 W / cm degree K, the temperature gradient in the cross section of the core can be approximately estimated for one running centimeter, assuming that all the heat is absorbed on the axis of the core and scattered on its surface, according to the formula :

,

,

where δТ is the temperature field gradient equal to the temperature difference in the center and on the surface of the round active core;

p is the power of the heat flux dissipated from each linear centimeter of the active core;

r is the radius of the core;

λ is the coefficient of thermal conductivity.

With such a gradient, the change in the refractive index is very small and has practically no effect on the quality of the radiation.

Due to the low temperature gradients and the crossed placement of the plates 10 in each row 12, which compensates for the effect of induced birefringence, this effect also has practically no effect on the quality of the amplified laser beam.

With a large length of the amplification channel, the influence of spontaneous and other spurious emissions, including glare from the surfaces of optical elements, waveguide and unnecessary transverse modes, should be excluded. In the proposed embodiment, this is ensured by the fact that the through optical channel exists in each row only in the immediate vicinity of the active core. Due to the fact that adjacent plates are rotated relative to each other by 90 degrees, only the ends of the active cores and the adjacent small part of the remaining surface of the end face are in optical contact. Through the remainder, all transverse modes are scattered, except for the fundamental, as well as spurious emission and amplified spontaneous emission. This part of the end surfaces of the plates may have an absorbing coating to block the propagation of any radiation propagating at an angle to the optical axes of the rows of which the multi-channel amplifier is composed.

These measures do not work within the angular aperture determined by the geometry of the channel and the difference in refractive indices in the cross section of the amplification channel in accordance with the formulas:

α ₁ = d / L;

Where:

d is the cross-sectional size of the transparent amplification channel;

L is the length of the channel;

n ₁ , n ₂ - the maximum and minimum refractive indices in the cross section of the active core.

This region is rather narrow due to the large ratio of the length and cross section of each amplifier channel and the small temperature gradient, therefore, the power density of harmful radiation within the specified angular aperture can be made quite low compared to the power density of the radiation entering the channel input from expander 4. This creates the conditions for the dominance of the useful mode, in accordance with the rule according to which the probability of stimulated emission is proportional to the radiation power density giving into the region of the active medium excited by pumping.

The ability to achieve high quality high-power radiation at the output of a multi-beam laser source justifies the significant loss of radiation from the master oscillator due to the poor utilization of the beam cross section 4 exiting the expander 3. With a master oscillator power of several tens of watts and an output power of high-quality radiation from each of dozens of channels in several hundred watts, these losses can be neglected.

Thus, in a compact multipath source of laser radiation with pumping and cooling systems common to tens and hundreds of amplification channels, due to the multiple expansion of the radiation beam of the master oscillator, blocking the propagation of spurious and spontaneous radiation and a radical decrease in temperature gradients, the high quality of each beam of the multipath source is ensured , which allows focusing radiation using long-focus optics.

In another embodiment of the present invention, in order to reduce the influence of reflections from narrow end faces, the laser plates shown in FIG. 9 are made in the form of beveled parallelepipeds. In this embodiment, part of the plates 10 in each row, for example, even ones, have a wide pair of faces 14 in the shape of a parallelogram, and alternative plates have a longitudinal narrow pair of faces 13 in the shape of a parallelogram, with the corresponding angles of these parallelograms being equal, and the other faces of the plates being rectangular. The acute angle of the parallelograms may be equal to the Brewster angle. To eliminate astigmatism resulting from oblique incidence of rays, optical wedges can be installed at the input and output of the multichannel amplifier, or plates with end faces facing the input and output of each channel can have a corresponding shape.

In a third embodiment of the invention, in order to reduce the influence of diffraction effects by creating an apodizing transverse profile of the amplifier channel, in each row, the cross-sectional size of the active core 11 in the laser plates 10 increases as they approach the output of the amplifier, as shown in FIG. 10.

In the fourth embodiment of the invention, to compensate for the dispersion of group velocities during amplification of ultrashort pulses, all or part, for example, only plates equally oriented in space, 10 have a transparent diffraction grating 15 with a symmetrical stroke profile on each transverse narrow face shown in FIG. 11. This diffraction grating separates the radiation normally incident on it into spectral components, deflecting them at different angles in a plane perpendicular to the wide faces of the plate, and they propagate along the optical axis of the active core in the form of symmetrical waveguide modes due to total internal reflection from wide faces. The diffraction grating can be engraved directly on the end faces of the plate, or an external transparent grating can be installed on this surface. An engraved diffraction grating works in the same diffraction order, much like an echelette grating, but not in reflected, but in transmitted rays.

To reduce polarization losses during sequential passage through gratings with orthogonal strokes on even and odd plates, diffraction gratings should be arranged only on parts of the plates with the same face orientation, or quartz plates should be installed between the even and odd plates, rotating the plane of polarization 90 degrees .

One embodiment of a device for processing materials using the proposed multi-beam laser source is shown in FIG. 12. The device includes a bed 100 with a base surface 101, scanning laser heads 9 with focusing optics and a multipath source of laser radiation, consisting of a master oscillator 1, a laser beam expander 3 and a multipath laser amplifier 7. From the output of the amplifier 7, the laser radiation in the form of a large number of beams 5 through reflective prisms 8 it enters the input windows of the laser scanning heads 9, similar to the heads of the Cambridge Technology type L2H14X2. The output radiation 6 of these heads is directed to the base surface 101. The output windows of the laser heads are mounted above the base surface with overlapping scanning areas providing processing of the material with at least two beams 6. For example, scanning heads can be mounted above the vertices of imaginary squares or rectangles, conditionally dividing the base surface into sectors by the number of rays of the laser source, at a height determined by the formula h = d / tgα, where d is the diagonal length of the sector, α is the maximum angle ol scan.

The proposed installation of laser processing of materials when used, for example, for laser sintering of metal powders works as follows.

The metal powder in the amount necessary for sintering one layer is poured onto the base surface 101, then this layer is leveled and compacted. An array of laser beams 6 is formed, simultaneously used for sintering various sections of the treated layer. It happens as follows.

The master laser radiation generator 1 forms a thin, slightly divergent beam of electromagnetic radiation 2 with a good quality indicator. This radiation enters the input of the expander 3. A wide beam of radiation 4 from the output of the expander 3 is divided into fragments, passing to the input of the multi-channel amplifier 7 through the diaphragms 25 in the first collector of coolant 22. The radiation beams 5 amplified by the multi-channel active medium are output through the diaphragms 25 in the second collector coolant 22.

The thus formed multi-beam array of laser beams 5 is sent to the input windows of the laser scanning heads 9 using reflective prisms 8. The output windows of the scanning heads are located above the vertices of square or rectangular sectors, which conditionally divide the base surface into separate segments, at a height determined by the formula: h = d / tgα, where d is the diagonal length of the sector, α is the maximum scanning angle. As can be seen from FIG. 8, with this arrangement, the scanning region 91 of each beam 6 covers four sectors, excluding the rays 6 emerging from the scanning heads located above the outer boundary of the base surface 101.

In another embodiment of the laser material processing apparatus shown in FIG. 9, a rigid coordinate frame 103 is additionally used, with coordinate grid sensors 104 installed on its edges to allow adjustment errors of the scanning heads, while the edges of the coordinate frame extend above the centers of square sectors in the peripheral scanning zone not used for processing materials. As the sensitive surface of these sensors can be used optical fiber, the core of which has dimensions that provide sufficient accuracy of compensation. Error compensation is carried out programmatically using triangulation methods, for example, as proposed in the patent source [7].

In the third embodiment of the apparatus for laser processing of materials above the vertices of the squares into which the base surface is divided, two or more scanning heads are installed, as shown in FIG. 10, the output radiation of which with the help of mirrors 92 is directed to the common area of the base surface. In this case, the number of sectors into which the base surface is conventionally divided decreases in proportion to the number of scanning heads above each vertex, and the shape of the base surface can be square or rectangular.

Used sources

1. US 201301112672

2. US 7443903

3. US 6,270,604

4. US 5846638

5. US 6025060

6. US 6511571

7. US 7916375

8. Koechner, W., Solid-State Laser Engineering, Sixth Revised and Updated Edition, 2006, W.T. Rhodes et al., Eds., Springer Science + Business Media.

Claims (20)

1. A multipath source of laser radiation containing a master oscillator and a multi-channel amplifier, characterized in that - an extender is installed between the master oscillator and the multichannel amplifier, which increases the cross section of the laser beam of the master oscillator to the size of the input aperture of the multichannel amplifier; - a multi-channel amplifier consists of parallel rows, which are composed of sequentially located laser plates; - in each row, the laser plates are aligned so that their longitudinal axes lie on one straight line forming the optical axis of one of the amplification channels; - the rows of laser plates are arranged with the same pitch in the vertical and horizontal directions; - each laser plate is made in the form of a rectangular parallelepiped and contains a core made of active material elongated along the longitudinal axis of the plate and an inactive shell of optical material surrounding it from the sides with a refractive index equal to or close to the refractive index of the active material; - the transverse size of the projection of the core onto a wide face of the laser plate is less than the thickness of the plate; - the wide faces of the odd plates in all rows are arranged horizontally, the wide faces of the even plates are arranged vertically, and the longitudinal narrow faces of the plates facing each other in adjacent rows are optically interconnected. 2. A multipath source according to claim 1, characterized in that the active core of each laser plate in each row is made with a cross section that increases as it approaches the output of the amplifier 3. A multipath source according to claim 1, characterized in that at least a portion of the laser plates, equally oriented in space, have a transparent diffraction grating with a symmetrical line profile on each transverse narrow face with the possibility of dividing the radiation normally incident on it into spectral components with their deviation in the plane perpendicular to the wide faces of the plate, and their propagation along the optical axis of the active core in the form of symmetric waveguide modes due to the total internal reflection of t of wide faces, while in each row between the plates having diffraction gratings and differently oriented in space, optical elements are installed that can rotate the plane of polarization of the amplified radiation by 90 degrees. 4. Device for laser processing of materials, containing: - a bed with a base surface; - multipath source of laser radiation; - scanning laser heads with built-in focusing optics operating under the control of a computer program; - mirrors or prisms arranged to direct one of the beams of a multipath laser source to said scanning laser heads, characterized in that: - a multipath source of laser radiation is made in accordance with paragraph 1; - the base surface of the bed is divided into square or rectangular sectors in a computer program that controls the scanning laser heads; - the output windows of the scanning laser heads are placed above the vertices of these sectors at a height h = d / tgα, where d is the diagonal length of the sector, α is the maximum scanning angle. 5. The device according to claim 4, characterized in that it is provided with a coordinate frame with through openings located between the base surface of the bed and the output windows of the scanning laser heads, while the through openings are made in the form of sectors, and coordinate grid sensors are installed on the edges of the coordinate frame made with the possibility of correcting alignment errors of laser scanning heads, while the edges of the coordinate frame are located above the centers of the sectors and placed in the peripheral scanning zone, not used when processing material.

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