Laser processing head based on single-beam time-space characteristic regulation

Abstract

The invention provides a laser processing head based on single-beam time-space characteristic regulation. The laser processing head comprises a beam-splitting lens, an annular optical path system and a central optical path system; the annular optical path system comprises a first plane mirror, a conical lens group and a focusing objective; the central optical path system comprises a second plane mirror and a third plane mirror; a first laser beam split by the beam-splitting lens is reflected by the first plane mirror and then is incident into the conical lens group; the conical lens group generates a non-diffracted annular light beam for outputting to the focusing objective; the focusing objective outputs a fine annular focal spot obtained by focusing the non-diffracted annular light beam to the surface of a workpiece; a second laser beam split by the beam-splitting lens is reflected by the second plane mirror and the third plane mirror and then is incident into the focusing objective, and the focusing objective focuses the laser beam and then outputs a central fine circular spot to the surface of the workpiece. During laser boring by use of the laser processing head, excellent circular ring precision can be guaranteed, the heat effect area can be reduced and the hole edge quality can be improved.

Description

technical field [0001] The invention belongs to the field of laser processing, and in particular relates to a laser processing head adjusted based on the spatiotemporal characteristics of a single beam. Background technique [0002] Axicons include plano-convex (PCX) axicons and plano-convex (PCV) axicons. Plano-convex (PCX) axicons have a convex cone and a plane; plano-concave (PCV) axicons have a concave cone and a plane. They are used to produce a non-diffractive ring beam that increases in diameter with distance, yet maintains a consistent ring thickness. When used with a collimated Gaussian beam, a plano-convex (PCX) axicon will form an annular beam that approximates a Bessel beam and is suitable for a range of medical, research, measurement, and calibration applications. These axicons feature a precision fused silica substrate and are available uncoated as well as various AR coating options. A Bessel beam is a non-diffracting beam formed by a ring with equal power c...

AI Technical Summary

Problems solved by technology

[0005] Although the above two laser drilling technologies are widely used in the industrial field, they still have shortcomings for precision drilling, especially for micro-holes: 1) There are different drilling apertures for pulse single-point drilling and cutting. In the middle ground that is difficult to cover, in order to maintain sufficient energy density and hole roundness for pulse single-point drilling, the radius of the focal spot is generally below 50 microns, and the hole cutting requires a two-axis or three-axis interpolation movement of the motion mechanism to make the focal spot The spot moves relative to the workpiece, and for holes with too small diameter (for example, within 0.5mm), the precision of the motion mechanism is very high, which makes the cost of the laser drilling mechanism very high, and the roundness of the hole is often It is still not ideal; 2) Due to the existence of interpolation motion, the efficiency of cutting holes is far lower than that of pulse single-point drilling, and due to the limitation of the movement speed of the movement mechanism, excessive laser power cannot be used, which limits the use of high-power lasers. 3) For materials with anisotropic thermal conductivity, the focal spots of pulse single-point drilling and cutting holes are all Gaussian energy distributions, making the heat-affected zone inconsistent in different directions, which directly affects the roundness and The quality of the edge of the hole is prone to thermal stress deformation; 4) The high pulse energy of pulse single-point drilling and cutting all acts on the same position at the same time, causing violent melting, vaporization and plasma phenomena, and a large amount of laser energy is wasted in redundant In melting, vaporization and plasma absorption, the heat-affected zone increases, and it is difficult to improve the quality of drilling

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