CN117047307A - Dynamic light spot cutting adjusting device and cutting method based on vortex light beams - Google Patents
Dynamic light spot cutting adjusting device and cutting method based on vortex light beams Download PDFInfo
- Publication number
- CN117047307A CN117047307A CN202311110537.9A CN202311110537A CN117047307A CN 117047307 A CN117047307 A CN 117047307A CN 202311110537 A CN202311110537 A CN 202311110537A CN 117047307 A CN117047307 A CN 117047307A
- Authority
- CN
- China
- Prior art keywords
- vortex
- laser
- cutting
- dynamic
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005520 cutting process Methods 0.000 title claims abstract description 70
- 238000000034 method Methods 0.000 title claims abstract description 19
- 230000003287 optical effect Effects 0.000 claims abstract description 23
- 230000005684 electric field Effects 0.000 claims abstract description 10
- 230000010287 polarization Effects 0.000 claims description 76
- 239000004973 liquid crystal related substance Substances 0.000 claims description 34
- 239000000463 material Substances 0.000 claims description 28
- 238000012545 processing Methods 0.000 claims description 20
- 238000009826 distribution Methods 0.000 claims description 12
- 230000033001 locomotion Effects 0.000 claims description 12
- 238000003698 laser cutting Methods 0.000 claims description 10
- 238000005457 optimization Methods 0.000 claims description 7
- 230000003111 delayed effect Effects 0.000 claims description 3
- 230000010363 phase shift Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 11
- 230000002902 bimodal effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000004988 Nematic liquid crystal Substances 0.000 description 2
- 238000002679 ablation Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 241001270131 Agaricus moelleri Species 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/36—Removing material
- B23K26/38—Removing material by boring or cutting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/70—Auxiliary operations or equipment
- B23K26/702—Auxiliary equipment
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- Laser Beam Processing (AREA)
Abstract
The application discloses a dynamic facula cutting adjusting device and method based on vortex beams, comprising a laser light source for emitting laser beams, a collimating mirror for collimating and distributing the laser beams, a reflecting mirror for changing the optical path of the laser beams, a rotating mirror component for deflecting the laser beams in the X/Y axis direction, and a focusing mirror component for focusing the laser beams, wherein a vortex beam generating element is arranged between the reflecting mirror and the rotating mirror component, the laser beams reflected by the reflecting mirror generate vortex beams with adjustable orbital angular momentum on the vortex beam generating element, and the generation and switching of the orbital angular momentum of the vortex beams are completed by applying an electric field. The X/Y axis deflection of the vortex beam is completed through the rotary mirror assembly, and the focusing mirror assembly is utilized to focus the collimated laser beam. The application combines the scanning characteristics of double helix, the energy density of the light beam can be further optimized through the helix angle and the scanning amplitude, the optimized light beam which can realize better cutting of the inner wall is obtained, and the whole cutting effect is improved.
Description
Technical Field
The application belongs to the field of laser processing, and particularly relates to a dynamic light spot cutting adjusting device and a cutting method based on vortex beams.
Background
In precision machining, under the condition of the overall dynamic characteristics of the current Gaussian beam and the flat-top beam carried by the characteristic beam, ablation and chipping of the titanium alloy are still affected by an ablation threshold value, so that the problem of poor characteristics of a cutting surface is generated. In particular, many laser heads use gaussian beams for laser cutting, but the concentration of the gaussian beam energy density causes problems of excessive burning in the case of excessively high energy density and poor melt pool fluidity in the case of low energy density.
Vortex beams are a type of beam with a circular intensity distribution, a helical wavefront structure, with an orbital angular momentum in addition to a spin angular momentum. Due to the dynamic property and quantum property of vortex light beam with orbital angular momentum, the vortex light beam has spiral phase wavefront to bring central phase singular point, thus generating hollow light distribution rotation light beam, which has important harbor value and application in many fields of particle manipulation, high-capacity high-speed large-scale optical communication, quantum information processing, super-resolution micro imaging and the like, and attracts more and more attention and research interest, and meanwhile, in the transmission process, the light beam center has phase singular point, and the light intensity is zero, no heating effect and no diffraction effect at the singular point.
Accordingly, in order to solve the problems in the prior art, it is desirable to provide a laser cutting method that optimizes the processing surface characteristics based on the dynamic beam mounting vortex beam.
Disclosure of Invention
Aiming at the problems in the related art, one of the purposes of the application is to provide a dynamic light spot cutting adjusting device based on vortex light beams, which further optimizes the processing surface characteristics based on the variable orbital angular momentum OAM carried by the dynamic light beams, so as to overcome the technical problems in the prior art.
The technical scheme of the application is realized as follows:
a dynamic facula cutting and adjusting device based on vortex light beams comprises a laser light source for emitting laser beams, a collimating lens for collimating and distributing the laser beams, a reflecting lens for changing the light path of the laser beams, a rotating lens component for deflecting the laser beams in X/Y axis directions, a focusing lens component for focusing the laser beams,
a vortex beam generating element is arranged between the reflecting mirror and the rotating mirror assembly, a laser beam reflected by the reflecting mirror generates a vortex beam with adjustable orbital angular momentum on the vortex beam generating element, and the generation and switching of the orbital angular momentum of the vortex beam are completed by applying an electric field;
the high-frequency dynamic vibration of the focus light spot in the X/Y axis direction is realized by driving the rotary mirror assembly to reciprocate at an angle in the rotation axis direction, and the double-helix three-dimensional track dynamic light beam with a three-dimensional dynamic profile is formed by driving the focus mirror assembly to vibrate or reciprocate in the optical axis direction to realize the high-frequency dynamic vibration of the focus light spot in the Z axis direction;
the focused laser beam is emitted to the material to be cut through the double spiral tracks of the three-dimensional tracks and the adjustable orbital angular momentum vortex beam, the focus light spot of the laser beam is controlled to fall in the material to be cut, and the focus light spot of the laser cutting is moved along the preset cutting track to finish the cutting of the material.
Preferably, the vortex beam with adjustable orbital angular momentum deflects in the X/Y axis direction of the vortex beam through the rotating mirror assembly, then focuses the straight laser beam by using the focusing mirror assembly, the focused laser irradiates the material to be cut, the focus spot of the laser is controlled to fall in the material to be cut, and the focus spot of the laser cutting is moved along a preset cutting track to finish the cutting of the material.
Preferably, a green polarizer is disposed between the collimator and the reflector, and is configured to polarize the collimated laser beam passing through the collimator, and then reflect the polarized laser beam onto the vortex beam generating element through the reflector.
This arrangement allows the collimated laser beam to pass through the green polarizer to obtain a polarized laser beam.
Preferably, a lambda/2 wave plate is also arranged between the green polarizer and the collimator mirror.
By means of the arrangement, relative phase delay is generated between the polarized components of the collimated laser beams, which are perpendicular to each other in the vibration direction, through the lambda/2 wave plate, so that the polarization characteristic of the polarized light is changed, and after the laser beams passing through the lambda/2 wave plate pass through the green polarizer, scattering of the transmitted e polarized component of an incident laser beam or a light field can be minimized.
Preferably, a lambda/4 wave plate is arranged between the vortex beam generating element and the rotary mirror assembly, and the fast axis direction of the vortex beam in the lambda/4 wave plate forms an included angle with the horizontal direction. The direction of a Light vector (Light vector) of the vortex beam with a low propagation speed in the wave plate is a slow axis, and the direction of a Light vector with a high propagation speed in the wave plate is a fast axis.
Preferably, the included angle between the fast axis direction and the horizontal direction of the vortex beam in the lambda/4 wave plate is-45 degrees, and the switching time of the orbital angular momentum of the vortex beam is 2-6 ms.
Preferably, the vortex beam generating element is one of a liquid crystal fork polarization grating, a spiral zone plate, a spatial light modulator, a super surface element, a q-wave plate or a mode converter.
Preferably, the vortex beam generating element is a liquid crystal fork-shaped polarization grating, each pixel on the liquid crystal fork-shaped polarization grating generates a phase shift Oxy at a corresponding position (x, y) on the cross section of the beam, and after the laser beam is reflected on the liquid crystal fork-shaped polarization grating, the horizontal component of the polarization vector of the vortex beam is delayed by an amount of xy relative to the vertical component;
when Φxy=0, the polarization produced is linear, i.e., linearly polarized light is produced; polarization refers to the relative magnitude and phase relation of polarization components in all directions in the light wave, and can be linear polarization, circular polarization, elliptical polarization and the like;
when Φxy=λ/4, the polarization produced is circular, i.e. circularly polarized light is produced; polarization is a phenomenon in which the vibration direction of an electric field vector in electromagnetic waves is in a specific plane;
when the amount Φxy is otherwise elliptical, the resulting polarization is elliptical, i.e. elliptical polarized light is produced.
Preferably, the phase configuration adjustment of the liquid crystal Fork Polarization Grating (FPG) is set with reference to:
wherein Txy is the phase adjustment output phase of the lambda/2 wave plate and the vortex beam generating element, Q is the phase of the lambda/4 wave plate, P corresponds to the pixel position of the liquid crystal fork-shaped polarization grating, xy corresponds to the phase, pxy is the corresponding phase at the pixel position xy of the liquid crystal fork-shaped polarization grating, and e iΦx 、The polarization state of the polarization grating element, namely the polarization state of the liquid crystal fork-shaped polarization grating;
equation 4 is a control finger of 0 to 4pi vortex phase corresponding to the amount of Φxy driving the pixel retardation of the liquid crystal fork polarization grating,is the polarization state of the liquid crystal fork-shaped polarization grating.
Preferably, the calculation formula of the vortex beam energy density is as follows:
wherein P (V) is vortex beam energy density,e0 is the energy amplitude of the beam waist, w0 is the radius of the beam waist, m is the order of the vortex beam, θ corresponds to the phase angle (0-2pi), r is the different positions of the vortex beam along the optical axis direction, E (r, θ, 0) is the light field amplitude expression, I 0 For beam waist position energy density, exp (im theta) is the magnitude at which the i imaginary term corresponds to the spatial phase.
The second object of the present application is to provide a dynamic spot cutting method based on vortex beam, using the above-mentioned dynamic spot cutting optical system adjusting device, the cutting method includes the following steps:
step s1., emitting a laser beam through a laser source, carrying out collimation and light distribution on the laser beam through a collimating mirror, and reflecting the collimated beam to a vortex beam generating element after the collimated beam irradiates a reflecting mirror;
step S2, generating vortex beams with adjustable orbital angular momentum on the vortex beam generating element by the laser beams reflected by the reflecting mirror, and completing generation and switching of the orbital angular momentum of the vortex beams by applying an electric field;
s3., the vortex beam irradiates on a rotating mirror assembly, the rotating mirror assembly deflects the vortex beam in the X/Y axis direction, the vortex beam is focused by a focusing mirror assembly and dynamically vibrates in the Z axis direction, and a double-helix three-dimensional track dynamic beam with a three-dimensional dynamic profile is formed, wherein the double-helix three-dimensional track dynamic beam has double helix and three-dimensional motion characteristics; the focused laser beam is emitted to the material to be cut through the double spiral track of the three-dimensional track and the vortex beam with adjustable Orbital Angular Momentum (OAM), the focus light spot of the laser is controlled to fall in the material to be cut, and the focus light spot of the laser cutting is moved along the preset cutting track to finish cutting the material.
Preferably, the dynamic spot cutting method further comprises the following steps: based on the three-dimensional motion track of the double-spiral three-dimensional track dynamic light beam, proper vortex handedness of the vortex light beam is selected for laser processing through judgment and optimization of vortex handedness.
The application has the beneficial effects that:
1. the application verifies the optimization of energy density control and peak spacing adjustment by hollow energy control of vortex beams. The hollow energy interval optimization beam scheme is adjusted through the hierarchical control of vortex beams, the scanning characteristics of double spirals are combined, the whole beam energy density can be further optimized through the spiral angle and the scanning amplitude, the optimized beam capable of achieving better cutting of the inner wall is obtained, and the whole cutting effect and the cutting capacity are improved.
2. The cutting direction is matched with the dynamic track and the spiral handedness to be optimized, the cutting direction is combined with the scanning characteristic, and in the spiral line ascending and descending process, the spiral angle carries out radial polarization through the movement direction by the vortex scheme, so that the cutting quality can be further improved.
3. Through the control of the cutting section and the verification of the slotting optimization scheme, the difference between Gaussian light and vortex light beams can be obtained, the energy density of the Gaussian light is concentrated, the overburning problem under the condition of overhigh energy density can be caused, and the problem of poor liquidity of a molten pool under the condition of low energy density can be caused.
Drawings
FIG. 1 is a schematic view of an optical path of a dynamic flare cutting adjustment device based on a vortex beam;
FIG. 2 is a diagram of a double helix three-dimensional track formed by the vortex beam-based dynamic light spot cutting adjustment device of the present application;
FIG. 3 is a diagram showing different orders of phase configuration of vortex beam based on the dynamic light spot cutting and adjusting device of the application;
FIG. 4 is a diagram showing the phase configuration of the handedness phase control left-right hand rotation of the dynamic spot cutting adjustment device based on vortex beams;
FIG. 5 is a graph showing the focus energy distribution of different orders of a vortex beam-based dynamic spot cutting adjustment device of the present application;
FIG. 6 is a graph of the judgment and optimization results of the cutting dynamic light and vortex light handedness of the dynamic light spot cutting adjustment device based on vortex light beams;
FIG. 7 is a graph showing the effect of the dynamic light energy distribution of the dynamic light spot cutting adjustment device based on vortex beam on the inner wall processing characteristics and the melt flow control;
FIG. 8 is a graph of vortex light level control and peak spacing assessment of the vortex beam-based dynamic spot cutting adjustment apparatus of the present application;
reference numerals:
1. a laser light source; 2. a collimator lens; 3. a lambda/2 wave plate; 4. a green polarizer; 5. a reflecting mirror; 6. a vortex beam generating element; 7. a lambda/4 wave plate; 8. an x-axis rotating mirror; 9. a Y-axis rotating mirror; 10. a focusing mirror assembly.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Example 1
As shown in fig. 1 and 2, a dynamic spot cutting adjustment device based on a vortex beam comprises a laser light source 1 for emitting a laser beam, a collimating mirror 2 for collimating and distributing the laser beam, a reflecting mirror 5 for changing the optical path of the laser beam, a rotating mirror assembly for deflecting the laser beam in the X/Y axis direction, and a focusing mirror assembly for focusing the laser beam, wherein a vortex beam generating element 6 is arranged between the reflecting mirror 5 and the rotating mirror assembly, the laser beam reflected by the reflecting mirror 5 generates a vortex beam with adjustable orbital angular momentum on the vortex beam generating element 6, and the generation and switching of the orbital angular momentum of the vortex beam are completed by applying an electric field; the high-frequency dynamic vibration of the focus light spot in the X/Y axis direction is realized by driving the rotary mirror assembly to reciprocate at an angle in the rotation axis direction, and the double-helix three-dimensional track dynamic light beam with a three-dimensional dynamic profile is formed by driving the focus mirror assembly to vibrate or reciprocate in the optical axis direction to realize the high-frequency dynamic vibration of the focus light spot in the Z axis direction; the focused laser beam is emitted to the material to be cut through the double spiral tracks of the three-dimensional tracks and the adjustable orbital angular momentum vortex beam, the focus light spot of the laser beam is controlled to fall in the material to be cut, and the focus light spot of the laser cutting is moved along the preset cutting track to finish the cutting of the material.
The dynamic light spot cutting adjusting device controls the high-frequency dynamic vibration of the laser beam in the X/Y axis direction and the Z axis direction, so that the focus light spot is controlled to vibrate in a high frequency manner on a cutting track, and the high frequency is 1.5 kHz-4 kHz.
A green polarizer 4 is disposed between the collimator lens 2 and the reflecting mirror 5, and the green polarizer 4 is used for polarizing the collimated laser beam passing through the collimator lens 2, and then the polarized laser beam is reflected to the vortex beam generating element through the reflecting mirror 5. This arrangement allows the collimated laser beam to pass through the green polarizer 4 to obtain a polarized laser beam.
A lambda/2 wave plate 3 is also arranged between the green polarizer 4 and the collimator lens 2. The polarization characteristics of the collimated laser beam can be changed by generating a relative phase delay between the two polarization components of the collimated laser beam whose vibration directions are perpendicular to each other by the lambda/2 wave plate 3, and the laser beam passing through the lambda/2 wave plate 3 can minimize scattering of the transmitted e-polarized component of the incident laser beam or optical field after passing through the green polarizer 4.
A lambda/4 wave plate 7 is arranged between the vortex beam generating element 6 and the rotating mirror assembly, and the fast axis direction of the vortex beam in the lambda/4 wave plate 7 forms an included angle with the horizontal direction. The direction of a Light vector (Light vector) of the vortex beam with a low propagation speed in the wave plate is a slow axis, and the direction of a Light vector with a high propagation speed in the wave plate is a fast axis. The included angle between the fast axis direction and the horizontal direction of the vortex beam in the lambda/4 wave plate 7 is-45 degrees, and the switching time of the orbital angular momentum of the vortex beam is 2-6 ms.
The vortex beam generating element 6 is one of a liquid crystal fork-shaped polarization grating, a spiral zone plate, a spatial light modulator, a super-surface element, a q-wave plate or a mode converter. In this embodiment, preferably, the vortex beam generating element 6 is a liquid crystal fork polarization grating, each pixel on the liquid crystal fork polarization grating generates a phase shift Oxy at a corresponding position (x, y) on the beam cross section, and after the laser beam is reflected on the liquid crystal fork polarization grating, the horizontal component of the polarization vector of the vortex beam is delayed by an amount of xy relative to the vertical component;
when Φxy=0, the polarization produced is linear, i.e., linearly polarized light is produced; polarization refers to the relative magnitude and phase relation of polarization components in all directions in the light wave, and can be linear polarization, circular polarization, elliptical polarization and the like;
when Φxy=λ/4, the polarization produced is circular, i.e. circularly polarized light is produced; polarization is a phenomenon in which the vibration direction of an electric field vector in electromagnetic waves is in a specific plane;
when the amount Φxy is otherwise elliptical, the resulting polarization is elliptical, i.e. elliptical polarized light is produced.
By using a liquid crystal fork polarization grating as the vortex beam generating element 6, after a laser beam is irradiated onto the liquid crystal fork polarization grating through the reflecting mirror 5, the tunable control of the vortex phase Orbital Angular Momentum (OAM) of the vortex beam is realized by the global and local periodic arrangement of the nematic Liquid Crystal (LC) layer acting on the geometric phase (panharatnam-Berry phase), the Orbital Angular Momentum (OAM) of the vortex beam does not need complicated mechanical parts and structures, the spatial patterning array is realized by the complex and local periodicity of the nematic liquid crystal layer, the polarization hologram pattern is generated, the generation and switching of the Orbital Angular Momentum (OAM) is realized by the electric field application, thereby the liquid crystal fork polarization grating has polarization control characteristics similar to those of an SLM element, which is a spatial light modulator, the SLM element can load information on one-dimensional or two-dimensional optical data fields so that diffraction efficiency of 95% or more can be realized by the liquid crystal fork polarization grating.
The phase configuration adjustment of the liquid crystal Fork Polarization Grating (FPG) is set with reference to:
wherein Txy is the phase adjustment output phase of the lambda/2 wave plate and the vortex beam generating element, Q is the phase of the lambda/4 wave plate, P corresponds to the pixel position of the liquid crystal fork-shaped polarization grating, xy corresponds to the phase, pxy is the corresponding phase at the pixel position xy of the liquid crystal fork-shaped polarization grating, and e iΦx 、The polarization state of the polarization grating element, namely the polarization state of the liquid crystal fork-shaped polarization grating;
equation 4 is the control relationship of 0 to 4pi vortex phase corresponding to the amount of Φxy of the pixel delay driving the liquid crystal fork polarization grating,is the polarization state of the liquid crystal fork-shaped polarization grating.
The rotary mirror assembly comprises an X-axis rotary mirror and a Y-axis rotary mirror 9, and piezoelectric elements are used for respectively driving the X-axis rotary mirror and the Y-axis rotary mirror 9 to reciprocate around respective rotating shaft directions to realize high-frequency vibration of a focus spot in the X/Y axis direction; dynamic adjustment of the light beam on the XY plane of the working surface is realized by using the galvanometer unit; then, the piezoelectric element or the motor is used for driving the swing arm to drive the focusing mirror assembly 10 so that the focusing light beam vibrates along the optical axis direction to realize high-frequency vibration of the focus light spot along the Z axis direction; the three-dimensional coordinate equation of the coordinate dynamic track of the focal spot is completed, and the coordinate dynamic track is converted into a laser scheme for cutting materials with a large aperture ratio by defining the swing angle of an XY reciprocating motor and Z coordinate driving control of a piezoelectric element, so that scanning of laser high-frequency dynamic beams is realized, a double-spiral three-dimensional track dynamic beam with a three-dimensional dynamic profile is formed as shown in fig. 2, a laser processing process is optimized by matching the double-spiral track beam with the three-dimensional track through an OAM vortex beam with adjustable track angular momentum, and the cutting and drilling process is more efficient.
The high-frequency vibration of the focus spot in the Z-axis direction is realized by the following method, the reflecting mirror 5 adopts a variable curvature reflecting mirror 5, and the change of curvature of the variable curvature reflecting mirror 5 is controlled to control the size of the divergence angle of the laser beam to change reciprocally, so that the vibration change of the focus spot in the Z-axis after passing through the focusing mirror assembly 10 is controlled. Or the high-frequency vibration of the focus spot in the Z-axis direction is achieved by driving the focusing mirror assembly 10 to vibrate in the optical axis direction using the piezoelectric element. The rotational axes of the X-axis rotary mirror and the Y-axis rotary mirror 9 are perpendicular to each other.
The calculation formula of the vortex beam energy density is as follows:
wherein P (V) is vortex beam energy density, E0 is beam waist energy amplitude, w0 is beam waist radius, m is vortex beam order, order m is orbital angular momentum of vortex beam, also called topological charge number, simply means that around the center of beam, the change of phase is multiple of 2 pi, theta corresponds to phase angle (0-2 pi), r is different positions of vortex beam along the optical axis direction, E (r, theta, 0) is light field amplitude expression, I 0 For beam waist position energy density, exp (im theta) is the magnitude at which the i imaginary term corresponds to the spatial phase. As shown in fig. 3, the phase configurations generated by the different orders are also different.
Table 1 below shows the energy density distribution of different orders, and it can be seen from the combination of Table 1 and FIG. 5 that the position of the peak energy density and the magnitude of the peak energy density are higher, and the higher the order is, the greater the peak energy density is, and the greater the position of the peak energy density is.
TABLE 1 energy density references for different orders
The calculation formula of Gaussian light energy density is as follows:
when the order m is equal to 1, the peak energy density position r (Ipeak) of the vortex beam isThe corresponding peak energy density Ipeak is +.>The ratio of gaussian beam energy density to vortex beam energy density is: />I.e. the gaussian optical energy density is 2.7 times the vortex optical energy density. Therefore, the peak energy density of the vortex beam is lower than that of the Gaussian beam, and the problem of energy density concentration at the center position of the vortex beam can be avoided, so that the problems of overburning under the condition of overhigh energy density and poor molten pool fluidity under the condition of low energy density caused by the energy density concentration of the Gaussian beam are solved.
FIG. 8 shows the relationship between vortex beam order control and peak spacing evaluation, wherein the vortex beam orders are different, the polarization components in the X direction and the Y direction are also different, the higher the order is, the larger the polarization components in the X direction and the Y direction are, the graph in the left side of FIG. 8 shows the peak variation of the corresponding light spot size and energy profile, and the right side table shows the spacing between the corresponding two energy peaks in the case of different orders; as shown in FIG. 7, which shows the different energy distributions of the laser beams corresponding to the inner wall processing characteristics and the melt flow control conditions, it can be seen from the graph a and the graph b of FIG. 7 that the double-spiral track and the adjustable track angular momentum vortex beam finally form a double-peak annular beam relative to a single-peak Gaussian beam, and the double-peak annular beam absorbs the inside of the material and acts on the slit of the external beam.
Example 2
The dynamic light spot cutting method based on vortex light beams, which uses the dynamic light spot cutting optical system adjusting device of the embodiment, comprises the following steps:
step s1., emitting a laser beam through a laser source, carrying out collimation and light distribution on the laser beam through a collimating mirror, and reflecting the collimated beam to a vortex beam generating element after the collimated beam irradiates a reflecting mirror;
step S2, generating vortex beams with adjustable orbital angular momentum on the vortex beam generating element by the laser beams reflected by the reflecting mirror, and completing generation and switching of the orbital angular momentum of the vortex beams by applying an electric field;
s3., the vortex beam irradiates on a rotating mirror assembly, the rotating mirror assembly deflects the vortex beam in the X/Y axis direction, the vortex beam is focused by a focusing mirror assembly and dynamically vibrates in the Z axis direction, and a double-helix three-dimensional track dynamic beam with a three-dimensional dynamic profile is formed, wherein the double-helix three-dimensional track dynamic beam has double helix and three-dimensional motion characteristics; the focused laser beam is emitted to the material to be cut through the double spiral track of the three-dimensional track and the vortex beam with adjustable Orbital Angular Momentum (OAM), the focus light spot of the laser is controlled to fall in the material to be cut, and the focus light spot of the laser cutting is moved along the preset cutting track to finish cutting the material.
Preferably, the amplitude of vibration in the X/Y axis direction is.+ -. 800. Mu.m, and the amplitude of vibration in the Z axis direction is.+ -. 10mm.
The implementation mode of the beam track of the application is different from the mode of a common 2-dimensional vibrating mirror in that: the track difference of the actual action of the light beam in the positive and negative focuses is large through the scanning track, the track realization in the material height direction is not facilitated, the problems of bidirectional difference in the processing speed direction, large dynamic change of the track difference and the like of track frequency control are solved, the 3-dimensional track is dynamically controllable through the Z direction, so that the difference points of the problems are more comprehensively solved on the focus track control, the control of the dynamic track is realized, and the dynamic track driving equation of the focus light spots is three: the first dynamic vibration track of the focus light spot, the second dynamic vibration track of the focus light spot and the third dynamic vibration track of the focus light spot are included, and specifically:
the first dynamic vibration track equation of the focal spot is as follows:
t＝[0,4*pi]；
x＝r*cos(t)；
y＝r*sin(t)；
z＝t*2；
wherein X, Y and z are three-dimensional coordinates, t is a driving parameter of a parameter equation, r is a constant, and the value range of r is +/-800 mu m which is set according to the radius of vibration in the X/Y axis direction; the first vibration track of the focus spot scans the focus spot track in a spiral line mode of a uniform cross-section circle to realize high-frequency movement of the spot focus along each direction of an optical axis, so that the energy distribution of a cross-section heat affected zone of a thick material workpiece is regulated, and the phenomena of slag hanging, rough stripes and the like of a laser cutting cross section are avoided;
the second dynamic vibration track equation of the focal spot is:
t＝[0,10*pi]；
x＝a*sin(t)+b*t*cos(t)；
y＝c*cos(t)-d*t*sin(t)；
z＝t；
wherein X, Y and z are three-dimensional coordinates, t is a driving parameter of a parameter equation, a, b, c, d is a constant, and each value range is +/-800 mu m which is set according to the radius of the vibration in the X/Y axis direction, so that the maximum amplitude is changed to the minimum amplitude; the second vibration track of the focus spot scans the focus spot track in a mexico top hat spiral mode, so that the high-frequency movement of the focus spot along each direction of an optical axis is realized, and the section processing quality is effectively improved;
the third dynamic vibration trajectory equation of the focal spot is:
t＝[0,4*pi]；
x＝a*cos(t)；
y＝b*sin(t)；
z＝t*2；
wherein X, Y and z are three-dimensional coordinates, t is a driving parameter of a parameter equation, a and b are constants, a is equal to b, the value ranges of the a equal to or less than 800 mu m according to the radius setting of the vibration amplitude in the X/Y axis direction, and the setting of the long axis and the short axis of the elliptical spiral line is realized; the third vibration track of the focus light spot scans the focus light spot track in an elliptic spiral line interval mode, so that high-frequency movement of the light spot focus along each direction of an optical axis is realized, the section inclination angle is effectively improved, and the subsequent processing procedures of processing are reduced.
The dynamic light spot cutting method further comprises the following steps: based on the three-dimensional motion track of the double-spiral three-dimensional track dynamic light beam, proper vortex handedness of the vortex light beam is selected for laser processing through judgment and optimization of vortex handedness.
According to the rotation direction of the light vector, people divide the vortex light beam into a left vortex light beam and a right vortex light beam, and as azimuth items exist in the vortex light beam wave vector, the vortex light beam rotates along the propagation direction and is provided with a spiral phase wave front, and light waves carry quantitative OAM, so that different processing effects can be achieved by selecting the vortex light beam with adjustable Orbital Angular Momentum (OAM) corresponding to the rotation direction for cutting and drilling, and as shown in fig. 3, the phase configuration generated by the left and right rotation of the chiral phase control is also different. Positive vortex beams of which the orders are-1 and-2 are represented when m= -1 and m= -2, and negative vortex beams of which the orders are 1 and 2 are represented when m=1 and m=2, respectively. As shown in fig. 6, when the cutting mode is counterclockwise processing, when the three-dimensional motion track is clockwise motion, the vortex handedness selects the right hand and the left hand, namely, the right vortex beam and the left vortex optical rotation beam are selected to have better processing effects; when the cutting mode is clockwise processing, when the three-dimensional motion track moves clockwise, the right hand and the left hand are selected by the vortex handedness, and the right hand is selected to have better processing effect than the left hand, namely, the right-hand vortex beam is selected to have better processing effect.
In the transmission process, the center of the vortex beam is provided with a phase singular point, and the light intensity at the singular point is zero, no heating effect and no diffraction effect, so that the processing scheme that the phase energy is controlled at the hollow ratio of the vortex beam can be realized by matching the double-helix three-dimensional track dynamic beam with the vortex beam with the adjustable track angular momentum OAM corresponding to the rotation direction. At present, a single-mode laser can realize better hollow energy distribution, a multimode laser has weaker energy distribution in the center, the higher the vortex level is, the larger the corresponding hollow is, the earlier opening of a material notch can be realized by combining the energy peak value control and the whole scanning track of a double-helix scanning track, the problem of absorption in the notch is optimized more comprehensively, and the 'freezing cutting' can be realized by laser power control. "freeze cut" turns off the laser power abruptly during the cut while maintaining all other process parameters to force the cutting front to solidify in its original form. Referring specifically to the slit graph 7, the slit contrast of the unimodal gaussian beam and the annular beam formed by the present application is shown in fig. 7, where fig. 7a is a slit graph of the unimodal gaussian beam and fig. 7b is a slit graph of the bimodal annular beam, and it is known that, compared with the unimodal gaussian beam, the bimodal annular beam formed by the present application has a bimodal annular beam, in terms of the internal absorption of the material and the slit acting on the external beam, because the bimodal annular beam cuts through the energy between the two peaks, the energy overflow can be prevented, thereby realizing better expansion of the material slit, and the energy delay of the unimodal gaussian beam causes the slit performance to be reduced. According to the application, by adopting a vortex scanning light form and adopting energy control of a target light field, a better cutting section and a higher cutting speed are realized.
Variations and modifications to the above would be obvious to persons skilled in the art to which the application pertains from the foregoing description and teachings. Therefore, the application is not limited to the specific embodiments disclosed and described above, but some modifications and changes of the application should be also included in the scope of the claims of the application. In addition, although specific terms are used in the present specification, these terms are for convenience of description only and do not constitute any limitation on the application.
Claims (10)
1. A dynamic facula cutting adjusting device based on vortex light beams comprises a laser light source for emitting laser beams, a collimating lens for collimating and distributing the laser beams, a reflecting lens for changing the light path of the laser beams, a rotating lens component for deflecting the laser beams in X/Y axis directions, and a focusing lens component for focusing the laser beams,
a vortex beam generating element is arranged between the reflecting mirror and the rotating mirror assembly, a laser beam reflected by the reflecting mirror generates a vortex beam with adjustable orbital angular momentum on the vortex beam generating element, and the generation and switching of the orbital angular momentum of the vortex beam are completed by applying an electric field;
the high-frequency dynamic vibration of the focus light spot in the X/Y axis direction is realized by driving the rotary mirror assembly to reciprocate at an angle in the rotation axis direction, and the double-helix three-dimensional track dynamic light beam with a three-dimensional dynamic profile is formed by driving the focus mirror assembly to vibrate or reciprocate in the optical axis direction to realize the high-frequency dynamic vibration of the focus light spot in the Z axis direction;
the focused laser beam is emitted to the material to be cut through the double spiral tracks of the three-dimensional tracks and the adjustable orbital angular momentum vortex beam, the focus light spot of the laser beam is controlled to fall in the material to be cut, and the focus light spot of the laser cutting is moved along the preset cutting track to finish the cutting of the material.
2. The vortex beam based dynamic spot cutting adjustment device according to claim 1, wherein a green polarizer is arranged between the collimator and the mirror, the green polarizer is used for polarizing the collimated laser beam after passing through the collimator, and the polarized laser beam is reflected onto the vortex beam generating element through the mirror.
3. The vortex beam based dynamic spot cut adjustment device according to claim 2, characterized in that a λ/2 wave plate is further provided between the green polarizer and the collimator mirror.
4. The vortex beam based dynamic spot cutting adjustment device according to claim 1, wherein a λ/4 wave plate is arranged between the vortex beam generating element and the rotating mirror assembly, and the vortex beam has an angle between the fast axis direction and the horizontal direction in the λ/4 wave plate.
5. The vortex beam based dynamic spot-cutting adjustment device of any one of claims 1-4, wherein the vortex beam generating element is one of a liquid crystal fork polarization grating, a spiral zone plate, a spatial light modulator, a super surface element, a q-wave plate, or a mode converter.
6. The vortex beam based dynamic spot cut adjustment device according to claim 5, wherein the vortex beam generating element is a liquid crystal fork polarization grating, each picture element on the liquid crystal fork polarization grating generates a phase shift Oxy at a corresponding position (x, y) on the beam cross section, and after the laser beam is reflected on the liquid crystal fork polarization grating, the horizontal component of the polarization vector of the vortex beam is delayed by an amount Φxy with respect to the vertical component;
when Φxy=0, the polarization produced is linear;
when Φxy=λ/4, the polarization produced is circular;
when the amount Φxy is in other cases, the resulting polarization is elliptical.
7. The vortex beam based dynamic spot cut adjustment device of claim 6 wherein the phase configuration adjustment of the liquid crystal fork polarization grating is set with reference to:
wherein Txy is the phase adjustment output phase of the lambda/2 wave plate and the vortex beam generating element, Q is the phase of the lambda/4 wave plate, P corresponds to the pixel position of the liquid crystal fork-shaped polarization grating, xy corresponds to the phase, P xy For the corresponding phase at the pixel position xy of the liquid crystal fork-shaped polarization grating, e iΦx 、A polarization state of the polarization grating element;
equation 4 is the control relationship of 0 to 4pi vortex phase corresponding to the amount of Φxy of the pixel delay driving the liquid crystal fork polarization grating,is the polarization state of the liquid crystal fork-shaped polarization grating.
8. The vortex beam based dynamic spot cutting adjustment apparatus of claim 6 wherein the vortex beam energy density is calculated as:
wherein P (V) is vortex beam energy density, E0 is beam waist energy amplitude, w0 is beam waist radius, m is vortex beam order, θ corresponds to phase angle (0-2pi), r is different positions of vortex beam along optical axis direction, E (r, θ, 0) is light field amplitude expression, I 0 For beam waist position energy density, exp (im theta) is the magnitude at which the i imaginary term corresponds to the spatial phase.
9. A dynamic spot cutting method based on a vortex beam, characterized in that a dynamic spot cutting optical system adjusting device according to any one of claims 1 to 8 is used, the cutting method comprising the steps of:
step s1., emitting a laser beam through a laser source, carrying out collimation and light distribution on the laser beam through a collimating mirror, and reflecting the collimated beam to a vortex beam generating element after the collimated beam irradiates a reflecting mirror;
step S2, generating vortex beams with adjustable orbital angular momentum on the vortex beam generating element by the laser beams reflected by the reflecting mirror, and completing generation and switching of the orbital angular momentum of the vortex beams by applying an electric field;
in step s3., the swirling beam irradiates onto the rotating mirror assembly, the rotating mirror assembly deflects the swirling beam in the X/Y axis direction, the focusing mirror assembly focuses the swirling beam and dynamically vibrates the swirling beam in the Z axis direction to form a double-spiral three-dimensional track dynamic beam with a three-dimensional dynamic profile, the double-spiral track of the three-dimensional track is matched with the vortex beam with adjustable track angular momentum, the focused laser beam is emitted onto a material to be cut, a focus spot of laser is controlled to fall in the material to be cut, and the focus spot of laser cutting is moved along a preset cutting track to finish cutting the material.
10. The vortex beam based dynamic spot cutting method of claim 9, further comprising the steps of: based on the three-dimensional motion track of the double-spiral three-dimensional track dynamic light beam, proper vortex handedness of the vortex light beam is selected for laser processing through judgment and optimization of vortex handedness.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311110537.9A CN117047307A (en) | 2023-08-31 | 2023-08-31 | Dynamic light spot cutting adjusting device and cutting method based on vortex light beams |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311110537.9A CN117047307A (en) | 2023-08-31 | 2023-08-31 | Dynamic light spot cutting adjusting device and cutting method based on vortex light beams |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117047307A true CN117047307A (en) | 2023-11-14 |
Family
ID=88653482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311110537.9A Pending CN117047307A (en) | 2023-08-31 | 2023-08-31 | Dynamic light spot cutting adjusting device and cutting method based on vortex light beams |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117047307A (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010247230A (en) * | 2009-03-27 | 2010-11-04 | Chiba Univ | Laser beam machining method, laser beam machining method using circularly polarizing/optical vortex laser beam, manufacturing method of acicular member, and acicular member |
| CN102148067A (en) * | 2011-01-27 | 2011-08-10 | 西北工业大学 | Device for generating rotary combined vortex light beam |
| CN104007567A (en) * | 2014-06-12 | 2014-08-27 | 北京邮电大学 | Method of vortex light beam generating system with tunable orbital angular momentum state |
| CN106950557A (en) * | 2017-04-26 | 2017-07-14 | 哈尔滨工业大学 | A kind of single photon ranging ambient noise filtering method and single photon range unit modulated based on photon trajectory angular momentum |
| CN110471186A (en) * | 2019-08-16 | 2019-11-19 | 上海嘉强自动化技术有限公司 | One kind being based on the regulable ring-shaped hot spot ZOOM cutter device of aspherical mirror and method |
| CN111338089A (en) * | 2020-01-16 | 2020-06-26 | 华中科技大学 | Optical system with annular light spots |
| CN112540457A (en) * | 2020-12-10 | 2021-03-23 | 武汉先河激光技术有限公司 | Vortex light beam generation device, system and method with adjustable topological number |
| CN113182672A (en) * | 2021-05-13 | 2021-07-30 | 广东宏石激光技术股份有限公司 | Thick material cutting method and system thereof based on dynamic control of three-dimensional track of laser spot |
| CN114784606A (en) * | 2022-03-23 | 2022-07-22 | 江苏师范大学 | Laguerre Gaussian beam generating device and method |
| CN114850660A (en) * | 2022-06-01 | 2022-08-05 | 广东宏石激光技术股份有限公司 | Laser processing method of vortex light beam |
| CN116571872A (en) * | 2023-05-30 | 2023-08-11 | 西安交通大学 | five+N dimension laser scanning processing system and method |
-
2023
- 2023-08-31 CN CN202311110537.9A patent/CN117047307A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010247230A (en) * | 2009-03-27 | 2010-11-04 | Chiba Univ | Laser beam machining method, laser beam machining method using circularly polarizing/optical vortex laser beam, manufacturing method of acicular member, and acicular member |
| CN102148067A (en) * | 2011-01-27 | 2011-08-10 | 西北工业大学 | Device for generating rotary combined vortex light beam |
| CN104007567A (en) * | 2014-06-12 | 2014-08-27 | 北京邮电大学 | Method of vortex light beam generating system with tunable orbital angular momentum state |
| CN106950557A (en) * | 2017-04-26 | 2017-07-14 | 哈尔滨工业大学 | A kind of single photon ranging ambient noise filtering method and single photon range unit modulated based on photon trajectory angular momentum |
| CN110471186A (en) * | 2019-08-16 | 2019-11-19 | 上海嘉强自动化技术有限公司 | One kind being based on the regulable ring-shaped hot spot ZOOM cutter device of aspherical mirror and method |
| CN111338089A (en) * | 2020-01-16 | 2020-06-26 | 华中科技大学 | Optical system with annular light spots |
| CN112540457A (en) * | 2020-12-10 | 2021-03-23 | 武汉先河激光技术有限公司 | Vortex light beam generation device, system and method with adjustable topological number |
| CN113182672A (en) * | 2021-05-13 | 2021-07-30 | 广东宏石激光技术股份有限公司 | Thick material cutting method and system thereof based on dynamic control of three-dimensional track of laser spot |
| CN114784606A (en) * | 2022-03-23 | 2022-07-22 | 江苏师范大学 | Laguerre Gaussian beam generating device and method |
| CN114850660A (en) * | 2022-06-01 | 2022-08-05 | 广东宏石激光技术股份有限公司 | Laser processing method of vortex light beam |
| CN116571872A (en) * | 2023-05-30 | 2023-08-11 | 西安交通大学 | five+N dimension laser scanning processing system and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109490201B (en) | Structured light generation device and method based on beam shaping | |
| CN106102982B (en) | Processing unit (plant) and method for laser-textured surface | |
| CN108883499B (en) | Method for producing a layer or a partial region of a layer of a three-dimensional component; corresponding computer program carrier | |
| US5841097A (en) | Process and apparatus for welding workpieces with two or more laser beams whose spots are oscillated across welding direction | |
| KR101004497B1 (en) | Device comprising one beam formation unit for introducing radiation energy into a workpiece consisting of a weakly-absorbent material | |
| US3848104A (en) | Apparatus for heat treating a surface | |
| CN102015189B (en) | Method for laser treating work pieces by way of a laser beam and a dynamic beam control of the laser beam | |
| JP7379375B2 (en) | Apparatus and method for manufacturing three-dimensional objects | |
| KR910009016B1 (en) | Laser processing apparatus | |
| CN112540457B (en) | Vortex light beam generation device, system and method with adjustable topological number | |
| CN101965579B (en) | Optical pattern generators using axicon segments | |
| CN103228400A (en) | Method and device for laser material processing a workpiece | |
| El-Khoury et al. | Utilizing fundamental beam-mode shaping technique for top-hat laser intensities in direct laser interference patterning | |
| JP2010207889A (en) | Method and device for producing periodic structure | |
| CN113759575A (en) | Method for regulating and controlling orientation of rotation axis of orbital angular momentum of space-time wave packet of focal field | |
| CN115453767A (en) | Point-ring distributed laser optical system and using method | |
| CN112548324A (en) | Laser welding method and apparatus for laser welding | |
| CN117047307A (en) | Dynamic light spot cutting adjusting device and cutting method based on vortex light beams | |
| CN104620157B (en) | Divergence changes device | |
| CN108345155A (en) | A kind of light-beam scanner and design method of three-dimensional tuning | |
| WO2020241138A1 (en) | Laser machining device and laser machining method using same | |
| CN109604837B (en) | Non-taper laser processing method | |
| JP6621614B2 (en) | Intermittent periodic structure creation device and intermittent periodic structure creation method | |
| Dubetsky et al. | Conical lens for atom focusing | |
| CN208013545U (en) | One kind cutting optical system based on four wedge laser scannings of rotation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |