Processing system for liquid conduction laser filamentation

Abstract

The invention discloses a processing system for liquid conduction laser filamentation, which comprises an ultrafast laser, a reflector and a coupling water nozzle, the reflector and the coupling water nozzle are sequentially arranged on a laser emergent light path of the ultrafast laser, the coupling water nozzle is used for spraying conduction liquid to a workpiece to be processed, and an optical lens group consisting of a plano-concave lens and a convex lens is arranged in the coupling water nozzle. After emergent laser parameters are set by the ultrafast laser, the output ultrafast laser is reflected by the reflector and then is emitted into the coupling water nozzle, the reflected ultrafast laser is coupled with the conducting liquid by the optical lens group in a proper light spot size, and filamentation laser is formed in the conducting liquid and is transmitted to the surface of a workpiece to realize precision machining; the invention solves the problems that the diameter of the water beam is difficult to be further reduced to adapt to higher-precision processing and the processing stability is influenced by the processing distance in the main stream water guide excitation processing.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrafast laser processing, and in particular relates to a processing system for liquid-conducting laser filamentation, which is suitable for precision laser processing. Background Art

[0002] Liquid conduction laser processing is a new type of processing technology, belonging to the field of precision special processing. This technology uses a steady-state liquid jet as a laser carrier to guide the laser to the surface of the workpiece to be processed. In this process, the refractive index difference between the liquid and the air forms an effect similar to that of an optical fiber, which limits the laser to be conducted in the liquid. Since the liquid cools and flushes the workpiece surface during processing, the thermal impact of laser processing on the workpiece is reduced. At present, the mainstream liquid conduction laser processing method is mainly based on water flow carrier.

[0003] However, high-power lasers attenuate greatly in water beams, which limits the processing rate. In current water-guided laser processing, the diameter of the water jet affects the processing accuracy. In order to improve the processing accuracy, the diameter of the water nozzle needs to be reduced. However, reducing the nozzle diameter will affect the stability and length of the water beam, thereby affecting the processing accuracy and stability, and limiting the scope of water-guided laser processing. Summary of the invention

[0004] In view of the stability and processing accuracy limitations of the current mainstream water-conducting laser in long-distance processing and fine processing, the purpose of the present invention is to provide an enhanced liquid-conducting laser filamentation processing system, which utilizes the characteristics of self-guided propagation and intensity of filamentation laser not being limited by transmission distance, so that the liquid-conducting laser processing process can be unaffected by the processing distance, while improving the stability of the fine processing process.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve the technical problem is: a processing system for liquid conduction laser filamentation, comprising an ultrafast laser, a reflector arranged in sequence on the laser emission optical path of the ultrafast laser, and an optical lens group composed of a plano-concave lens and a convex lens arranged in sequence on the optical path, and also comprising a coupling water nozzle for spraying a conductive liquid beam to a workpiece to be processed, the coupling water nozzle comprising an inverted cone-shaped cavity and a spray port located at the bottom end of the cavity, a liquid injection pipe is connected to the cavity, and there is a conductive liquid located below the optical lens group in the cavity. After the emission laser parameters are set, the ultrafast laser beam output by the ultrafast laser is reflected by the reflector and then injected into the coupling water nozzle, the plano-concave lens and the convex lens couple the reflected ultrafast laser beam with the conductive liquid to form a filamentation laser, the spray port sprays the conductive liquid beam, the filamentation laser is transmitted in the conductive liquid beam in a self-guided manner, and the initial light intensity and beam diameter are maintained under the conduction of the conductive liquid beam to propagate to the surface of the workpiece to be processed to achieve precision processing.

[0006] In the liquid-conducting laser filamentation processing system, the ultrafast laser is arranged horizontally, the reflector is arranged at 45 degrees, and the coupling water nozzle is arranged vertically.

[0007] The liquid-conducting laser filamentation processing system has an ultrafast laser beam central wavelength of 1030-1064nm, a pulse width of 50-100fs, and a single pulse energy of 1-1.5mJ.

[0008] The optical lens group of the liquid-conducting laser filamentation processing system is arranged in the coupling water nozzle.

[0009] The liquid-conducting laser filamentation processing system described above has a conducting liquid which is water.

[0010] Compared with the prior art, the beneficial effect of the present invention lies in that: by combining ultrafast laser filamentation technology with water-guided machining technology, the present invention utilizes the characteristics of filamentation laser that the intensity is stable during conduction and is not affected by the transmission distance, thereby solving the problem that the water beam in mainstream water-guided machining is difficult to further reduce the diameter to adapt to higher-precision machining and the problem that machining stability is affected by machining distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0012] The reference numerals of the figures are: 1—ultrafast laser, 2—ultrafast laser beam, 3—reflector, 4—liquid injection tube, 5—plano-concave lens, 6—convex lens, 7—coupling water nozzle, 8—conduction liquid beam, 9—filamentation laser, 10—workpiece to be processed. DETAILED DESCRIPTION

[0013] To facilitate understanding of the present invention, the present invention is described more comprehensively below in conjunction with the accompanying drawings and embodiments.

[0014] The mainstream water-guided processing method has the problem of large laser power attenuation, and is affected by the stability of the water beam during fine processing, resulting in poor stability during fine processing. Ultrafast laser filamentation is a unique nonlinear optical phenomenon that occurs when high-power ultrafast lasers are transmitted in transparent optical media. Under the combined effect of various optical effects, the filamented laser will undergo a physical phenomenon of self-guided transmission. The laser itself will not produce obvious divergence during the propagation process, and its transmission distance can far exceed the diffraction limit. At the same time, the laser light intensity is not limited by the transmission distance and remains at a very high level. Example

[0015] Reference Figure 1As shown, a processing system for liquid-conducting laser filamentation disclosed in the present invention comprises an ultrafast laser 1, a reflector 3 sequentially arranged on the laser emission optical path of the ultrafast laser 1, and a coupling nozzle 7 for spraying a conductive liquid toward a workpiece 10 to be processed, wherein an optical lens group is arranged in the coupling nozzle 7, and the optical lens group is composed of a plano-concave lens 5 and a convex lens 6 sequentially arranged on the optical path, wherein the coupling nozzle 7 comprises an inverted cone-shaped cavity and a spray port located at the bottom end of the cavity, wherein a liquid injection pipe 4 is connected to the cavity, and a conductive liquid is contained in the cavity below the optical lens group, wherein the ultrafast laser 1 is arranged After the output laser parameters are determined, the output ultrafast laser beam 2 is reflected by the reflector 3 and then injected into the coupling nozzle 7. The plano-concave lens 5 and the convex lens 6 couple the reflected ultrafast laser beam 2 with the conductive liquid by reasonably selecting the focal length and configuration distance, so that the incident ultrafast laser beam 2 is coupled into the conductive liquid with a suitable spot size to form a filament laser 9. The injection port injects the conductive liquid beam 8, and the filament laser 9 is transmitted in the conductive liquid beam 8 in a self-guided manner. Under the conduction of the conductive liquid beam 8, the initial light intensity and beam diameter are maintained and propagated to the surface of the workpiece 10 to be processed to achieve precision processing. The diameter and flow rate of the conductive liquid beam 8 are set by adjusting the coupling nozzle 7 to meet the processing requirements, so that the water flow has a certain ability to resist air disturbance and does not damage the processed surface.

[0016] In this embodiment, an ultrafast laser 1 is configured to output an ultrafast laser beam 2 with a central wavelength of 1030-1064 nm, a pulse width of 50-100 fs, and a single pulse energy of 1-1.5 mJ, which is incident on a coupling nozzle 7 by adjusting a reflector 3. The spot size of the ultrafast laser beam 2 is adjusted by adjusting a plano-concave lens 5 and a convex lens 6 in the coupling nozzle 7 so that the ultrafast laser beam 2 is incident on a conductive liquid beam 8 to generate a filamentary laser 9. The length and diameter of the conductive liquid beam 8 and the position of the workpiece 10 to be processed are adjusted according to the processing requirements, so that high stability and high degree of freedom of precision processing can be achieved. Example

[0017] In the processing system of this embodiment, the ultrafast laser 1 is arranged horizontally, the reflector 3 is arranged at 45 degrees, and the coupling water nozzle 7 is arranged vertically, so that the horizontally emitted ultrafast laser beam 2 eventually propagates vertically to the surface of the workpiece 10 to be processed, and the conductive liquid 7 is water.

[0018] Although the preferred embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, a person skilled in the art can make many specific changes without departing from the scope of protection of the invention and the claims, such as changing the wavelength of the ultrafast laser, adjusting the pulse width and the energy of a single pulse, appropriately changing the optical lens group and selecting different conductive liquids, all of which fall within the protection scope of the present invention.

Claims

1. A liquid-conducting laser filament processing system, characterized in that: The invention comprises an ultrafast laser (1), a reflector (3) arranged in sequence on the laser emission optical path of the ultrafast laser (1), and an optical lens group consisting of a plano-concave lens (5) and a convex lens (6), and also comprises a coupling nozzle (7), wherein the coupling nozzle (7) comprises an inverted cone-shaped cavity and an injection port located at the bottom end of the cavity, the cavity is connected to a liquid injection pipe (4), and the cavity contains a conductive liquid located below the optical lens group. The ultrafast laser beam (2) output by the ultrafast laser (1) is reflected by the reflector (3) and then injected into the coupling nozzle (7), the optical lens group couples the reflected ultrafast laser beam (2) with the conductive liquid to form a filament laser (9), the injection port injects the conductive liquid beam (8), and the filament laser (9) maintains the initial light intensity and beam diameter under the conduction of the conductive liquid beam (8) and propagates to the surface of a workpiece to be processed (10), thereby realizing precision processing of the workpiece.

2. A liquid-conducting laser filamentation processing system according to claim 1, characterized in that: The ultrafast laser (1) is arranged horizontally, the reflector (3) is arranged at 45 degrees, and the coupling water nozzle (7) is arranged vertically.

3. A liquid-conducting laser filamentation processing system according to claim 1 or 2, characterized in that: The ultrafast laser beam (2) has a central wavelength of 1030-1064 nm, a pulse width of 50-100 fs, and a single pulse energy of 1-1.5 mJ.

4. A liquid-conducting laser filamentation processing system according to claim 3, characterized in that: The optical lens group is arranged in the coupling water nozzle (7).

5. The liquid-conducting laser filamentation processing system according to claim 3, characterized in that: The conductive liquid is water.

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