Method and device for separating brittle transmissive materials with opposite-beam multi-focus laser

Abstract

The invention discloses a method and a device for correlative multi-focus laser separation of a fragile transmission material. The method is characterized in that the same technological parameters are adopted, and coaxial laser is utilized to penetrate multi-focus lens groups and to conduct inverse correlation on two sides in the thickness direction of the fragile transmission material to be separated, so that the number of focuses generated in the fragile transmission material is doubled to improve the laser energy absorption uniformity of the fragile transmission material in the thickness direction and to enhance the heating expansion uniformity of the fragile transmission material in the thickness direction. After a laser multi-focus beam leaves, the fragile transmission material is quickly cooled down in the thickness direction to produce tensile stress, so that separation of the thick fragile transmission material is realized by laser. The device comprises two sets of multi-focus laser processing systems and one three-dimensional working platform, wherein each set of the multi-focus laser processing system comprises a laser, light guiding mirrors, a beam expanding mirror and a multi-focus lens group. The method and the device realize high-quality, efficient and high-success-ratio separation of the thick fragile transmission material.

Description

technical field [0001] The invention belongs to the technical field of laser processing applications, and in particular relates to a method and device for separating brittle transmission materials by a through-beam multi-focus laser. The method is especially suitable for the separation of thick and brittle transmission materials such as KDP optical crystals. technical background [0002] Laser thermal cracking is currently an effective method for cutting and separating brittle transmission materials (such as glass, optical glass, optical crystal, etc.) to obtain high-quality separation edges. This method uses a laser focusing mirror to focus the laser beam on the surface or inside of a transparent material, and uses the high absorption rate of a certain band of laser light (such as a laser beam in the 10.6 μm band) of a brittle transmission material to form a surface to absorb laser energy, making the brittle transmission material Heating the surface of the material; or usin...

AI Technical Summary

Problems solved by technology

However, most of the existing multi-focus laser separation adopts the reflective focusing method to generate multi-focus laser (such as Chinese invention patent ZL201210118371.0). During the process of continuous reflection and propagation of the laser, the laser energy is continuously lost due to divergence, resulting in The number of laser focuses is small, and the energy distribution of each laser focus is quite different. Although the stress generated along the thickness direction has improved, there is still unevenness, and the unevenness becomes more serious as the thickness of the material increases. Therefore, laser cutting separation Material thickness is still limited

In addition, due to the inherent defects of the design method of this method of reflective focusing to generate multi-focus, the position of laser multi-focus generation and the energy distribution of the focus cannot be carried out according to the optimal design, which affects the thickness and quality of cutting and separating materials.

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