CN110732771A - dynamic controllable laser beam splitting device - Google Patents

Abstract

The invention discloses a dynamically controllable laser beam splitting device, comprising: a half-wave plate, a polarization beam splitting prism, a Faraday rotator, a pure phase liquid crystal spatial light modulator, and a focusing mirror; the incident beam passes through the half-wave plate, the polarization beam splitter sequentially Prisms, Faraday rotators, pure phase liquid crystal spatial light modulators, Faraday rotators, polarizing beam splitting prisms and focusing mirrors, and finally focus the split beam onto the surface of the workpiece to be processed. In the novel laser beam splitting device provided by the present invention, the damage thresholds of all optical devices are high enough to meet the requirements of high-energy pulsed laser processing. By introducing a spatial light modulator, the high-energy laser is encoded and then processed to realize the flexibility of the beam. The beam splitting device can be controlled and simplified, thereby greatly improving the efficiency of laser processing.

Description

A dynamic controllable laser beam splitting device

technical field

The invention belongs to the technical field of laser micromachining, and in particular relates to a dynamically controllable laser beam splitting device.

Background technique

The traditional laser micromachining technology usually adopts a single-focus processing method, that is, a laser beam focuses on the workpiece for drilling, cutting, welding, etching and other operations. When the processing requirements become complex, such as processing array holes, the single-focus processing method needs to drill holes one by one, and the processing efficiency will be very low. By splitting the laser beam to realize parallel processing of multiple laser beams, the processing time of the workpiece can be greatly shortened, thereby improving the laser processing efficiency.

At present, most of the laser beam splitting processing devices on the market are static beam splitting devices, for example, beam splitting mirrors, diffractive optical elements, etc. are used to split the incident beam. In the beam splitter method, a polarizing beam splitting prism is generally used for beam splitting, but the number of beam splitting is limited, and the more the number of beam splitting, the more complex the system and the higher the cost. The diffractive optical element method, such as the use of transmissive diffraction gratings, can generate multiple beams, but it lacks flexibility and can only process a fixed pattern, and cannot individually adjust any beam.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION An object of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages that will be described hereinafter.

The present invention provides the dynamically controllable laser beam splitting device, which solves the technical problems of fixed laser beam splitting and poor flexibility in the existing laser processing technology field.

In order to achieve these objects and other advantages according to the present invention, a dynamically controllable laser beam splitting device is provided, including: a half-wave plate, a polarization beam splitter prism, a Faraday rotator, a phase-only liquid crystal spatial light modulator, and a focusing mirror;

The incident beam passes through a half-wave plate, a polarizing beam splitter prism, a Faraday rotator, a pure phase liquid crystal spatial light modulator, a Faraday rotator, a polarizing beam splitter prism and a focusing mirror, and finally the split beam is focused on the surface of the workpiece to be processed. ;

The half-wave plate enables the incident beam to transmit the first horizontally polarized beam through the half-wave plate; the polarizing beam splitting prism transmits all the first horizontally polarized beam to the second horizontally polarized beam; the Faraday rotator transmits the second horizontally polarized beam The horizontally polarized light beam transmits the first 45° polarized light beam whose vibration direction is rotated by 45° under the action of the magneto-optical crystal in the optical rotator; The modulated second 45° polarized beam is reflected, and the vibration direction of the second 45° polarized beam is consistent with the first polarized 45° polarized beam; the second 45° polarized beam is formed under the action of the Faraday rotator A first vertically polarized light beam, the first vertically polarized light beam transmits a second vertically polarized light beam through a polarizing beam splitting prism; the focusing mirror splits the second vertically polarized light beam into a plurality of light beams.

Preferably, the Faraday rotator is a 45° Faraday rotator.

Preferably, the incident light beam adopts a femtosecond laser with a wavelength of 1030 nm.

Preferably, the half-wave plate is a half-wave plate with a wavelength of 1030 nm and a damage threshold of 10 J/cm ² @10 ns.

Preferably, the polarization beam splitter prism adopts a polarization beam splitter prism with a wavelength of 1030 nm and a damage threshold of 7 J/cm ² @10 ns.

Preferably, the Faraday rotator adopts an optical rotator with a wavelength range of 1030±10 nm and a damage threshold of 10 J/cm ² @10 ns.

Preferably, the pure-phase liquid crystal spatial light modulator is a reflective liquid crystal-on-silicon spatial light modulator with a suitable wavelength range of 1000 nm to 1100 nm and a high damage threshold. Compared with the traditional transmissive spatial light modulator, the pure-phase type is used. The reflective liquid crystal-on-silicon spatial light modulator modulates the light field and has the advantages of high energy utilization, high diffraction efficiency, and high fill factor.

Preferably, the focusing lens adopts a field lens with a near-infrared light antireflection coating and a high damage threshold on the surface.

Beneficial effects of the present invention:

1. The laser beam splitting device based on the pure-phase spatial light modulator provided by the present invention, by loading the spatial light modulator with phase distribution diagrams corresponding to different beam splitting conditions (number of split beams, energy distribution, position, etc.), The phase of the incident beam is modulated to achieve flexible control of any beam after splitting.

2. By introducing a spatial light modulator, the high-energy laser is encoded and then processed, the beam is flexible and controllable and the beam splitting device is simplified, thereby greatly improving the laser processing efficiency.

Other advantages, objects, and features of the present invention will appear in part from the description that follows, and in part will be appreciated by those skilled in the art from the study and practice of the invention.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a dynamically controllable laser beam splitting device according to one embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement it with reference to the description.

It should be understood that terms such as "having", "comprising" and "including" as used herein do not assign the presence or addition of one or more other elements or combinations thereof.

In one of the embodiments, as shown in FIG. 1 , a dynamically controllable laser beam splitting device according to the present invention includes: a half-wave plate 2 , a polarization beam splitting prism 4 , a Faraday rotator 6 , and a spatial light modulator 8 , focusing mirror 12; the incident light beam 1 passes through the half-wave plate 2, the polarizing beam splitting prism 4, the Faraday rotator 6, the spatial light modulator 8, the Faraday rotator 6, the polarizing beam splitting prism 4 and the focusing mirror 12 in turn, and finally the beam splitting The light beam is focused on the surface of the workpiece 14 to be processed.

The Faraday rotator 6 adopts a 45° Faraday rotator, the incident beam 1 adopts a femtosecond laser with a wavelength of 1030 nm, and the half-wave plate 2 adopts a half-wave plate with a wavelength of 1030 nm and a damage threshold of 10J/cm ² @10ns 2, the polarization beam splitter prism 4 adopts the polarization beam splitter prism 4 with a wavelength of 1030nm and a damage threshold of 7J/cm ² @10ns, and the Faraday rotator 6 adopts a light rotation with a wavelength range of 1030±10nm and a damage threshold of 10J/cm ² @10ns The spatial light modulator 8 is a reflective liquid crystal-on-silicon spatial light modulator 8 with a suitable wavelength range of 1000 nm to 1100 nm and a high damage threshold. field mirror.

In one of the embodiments, as shown in FIG. 1 , the working principle of a dynamically controllable laser beam splitting device according to the present invention is as follows:

The incident beam 1 is incident on the half-wave plate 2, and the transmitted beam is output as the first horizontally polarized beam 3 by manually rotating the half-wave plate 2;

The first horizontally polarized light beam 3 is incident on the polarizing beam splitting prism 4 and is completely transmitted, and the second horizontally polarized light beam 5 is output;

The second horizontally polarized beam 5 is incident on the Faraday rotator 6, and under the action of the magneto-optical crystal in the optical rotator, the first 45° polarized beam 7 whose vibration direction is rotated by 45° is transmitted;

The first 45° polarized beam 7 is vertically incident on the liquid crystal panel of the liquid crystal-on-silicon spatial light modulator 8, and after the phase modulation of the spatial light modulator 8, the second 45° polarized beam 9 is reflected, and the second 45° polarized beam 9 is reflected. The vibration directions of the polarized light beam 9 and the first 45° polarized light beam 7 are consistent;

The second 45° polarized beam 9 is incident on the Faraday rotator 6, and its vibration direction is rotated by 45° again to transmit the first vertically polarized beam 10;

The first vertically polarized light beam 10 is incident on the polarization beam splitter prism 4 and is completely reflected, and the second vertically polarized light beam 11 is reflected;

The vertically polarized light beam 11 is incident on the focusing mirror 12, and under the action of the focusing mirror, it emerges as a split beam 13, and the split beam 13 is focused on the surface of the workpiece 14 to be processed to process the workpiece.

Although embodiments of the present invention have been disclosed above, they are not limited to the applications set forth in the specification and embodiments. It can be fully adapted to various fields suitable for the present invention. Additional modifications can readily be implemented by those skilled in the art. Therefore, the invention is not to be limited to the specific details and illustrations herein shown and described, without departing from the general concept defined by the appended claims and the scope of equivalents.

Claims (8)

1. The dynamic controllable laser beam splitting device is characterized by comprising a half-wave plate, a polarization beam splitter prism, a Faraday optical rotator, a pure phase type liquid crystal spatial optical modulator and a focusing mirror, wherein an incident beam sequentially passes through the half-wave plate, the polarization beam splitter prism, the Faraday optical rotator, the spatial optical modulator, the Faraday optical rotator, the polarization beam splitter prism and the focusing mirror, and finally the split beam is focused on the surface of a workpiece to be processed;

   the half-wave plate enables incident light beams to transmit th horizontal polarized light beams through the half-wave plate, the polarization beam splitting prism enables th horizontal polarized light beams to transmit second horizontal polarized light beams, the Faraday rotator enables the second horizontal polarized light beams to transmit 45 th polarized light beams with the vibration direction rotated by 45 degrees under the action of magneto-optical crystals in the optical rotator, the spatial light modulator conducts phase modulation on the 45 th polarized light beams and reflects the modulated second 45-degree polarized light beams, the second 45-degree polarized light beams and the th 45-degree polarized light beams are in the vibration direction , the second 45-degree polarized light beams form th vertical polarized light beams under the action of the Faraday rotator, the vertical polarized light beams transmit second vertical polarized light beams through the polarization beam splitting prism, and the focusing mirror splits the second vertical polarized light beams into a plurality of light beams.
2. 2. The dynamically controllable laser beam splitting device according to claim 1, wherein the Faraday rotator is a 45 ° Faraday rotator.
3. 3. The dynamically controllable laser beam splitting device of claim 1, wherein the incident beam is a femtosecond laser with a wavelength of 1030 nm.
4. 4. The dynamically controllable laser beam splitting device according to claim 1, wherein the half-wave plate has a wavelength of 1030nm and a damage threshold of 10J/cm²A half-wave plate of @10 ns.
5. 5. The dynamically controllable laser beam splitting device according to claim 1, wherein the polarization beam splitter prism uses a wavelength of 1030nm and a damage threshold of 7J/cm²@10ns polarization splitting prism.
6. 6. The dynamically controllable laser beam splitting device according to claim 1, wherein the Faraday rotator uses a wavelength range of 1030 ± 10nm and a damage threshold of 10J/cm²An optical rotator of @10 ns.
7. 7. The dynamically controllable laser beam splitting device of claim 1, wherein the spatial light modulator is a reflective liquid crystal on silicon spatial light modulator with a high damage threshold for the applicable wavelength band of 1000 nm-1100 nm.
8. 8. The dynamically controllable laser beam splitting device of claim 1, wherein the focusing lens is a field lens coated with near infrared light antireflection film and having high damage threshold.

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