CN110732771A

CN110732771A - dynamic controllable laser beam splitting device

Info

Publication number: CN110732771A
Application number: CN201911075549.6A
Authority: CN
Inventors: 曹志良; 高峰; 武耀霞; 张晓宁; 宋昶; 杨小君
Original assignee: Xi'an Zhongke Micromach Photon Manufacturing Science And Technology Co Ltd
Current assignee: Xi'an Zhongke Micromach Photon Manufacturing Science And Technology Co Ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-01-31

Abstract

The invention discloses dynamically controllable laser beam splitting devices, which comprise a half-wave plate, a polarization beam splitter prism, a Faraday optical rotator, a pure phase type liquid crystal spatial light 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 pure phase type liquid crystal spatial light modulator, the Faraday optical rotator, the polarization beam splitter prism and the focusing mirror, and finally focuses the split beam on the surface of a workpiece to be processed.

Description

dynamic controllable laser beam splitting device

Technical Field

The invention belongs to the technical field of laser micromachining, and particularly relates to dynamically controllable laser beam splitting devices.

Background

The traditional laser micromachining technology usually adopts a single-focus processing mode, namely laser focuses to punch, cut, weld, etch and other operations on a workpiece, when the processing requirements become complex, for example, array group holes are processed, the single-focus processing mode needs to punch hole by hole, the processing efficiency is very low, and the processing time of the workpiece can be greatly shortened by splitting the laser beam to realize the parallel processing of multiple laser beams, thereby improving the laser processing efficiency.

At present, most laser beam splitting processing devices in the market are static beam splitting devices, for example, a beam splitter, a diffractive optical element and the like are adopted to split incident beams, a beam splitter method generally adopts a polarization beam splitter prism to split beams, but the number of the split beams is limited, the more the number of the split beams is, the more the system is complex, the higher the cost is, and a diffractive optical element method, for example, a transmission type diffraction grating is adopted to generate a plurality of beams, but the flexibility is lacked, only fixed patterns can be processed, and any beam cannot be independently adjusted.

Disclosure of Invention

objects of the present invention are to address at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.

The invention provides a laser beam splitting device with dynamically controllable light beams, which solves the technical problems of fixed laser beam splitting and poor flexibility in the technical field of laser processing.

To achieve these objects and other advantages in accordance with the purpose of the invention, there are provided dynamically controllable laser beam splitting devices including a half-wave plate, a polarization splitting prism, a Faraday rotator, a phase-only liquid crystal spatial light modulator, a focusing mirror;

an incident beam sequentially passes through a half-wave plate, a polarization beam splitter prism, a Faraday optical rotator, a pure phase type liquid crystal spatial optical modulator, a Faraday optical rotator, a polarization beam splitter prism and a 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 polarization light beams through the half-wave plate, the polarization beam splitter prism enables th horizontal polarization light beams to transmit second horizontal polarization light beams, the Faraday rotator enables the second horizontal polarization light beams to transmit 45 th polarization light beams with vibration directions rotated by 45 degrees under the action of magneto-optical crystals in the optical rotator, the pure phase type liquid crystal spatial light modulator conducts phase modulation on the 45 th polarization light beams and reflects the modulated second 45-degree polarization light beams, the second 45-degree polarization light beams and the th polarization 45-degree polarization light beams are in the same vibration direction , the second 45-degree polarization light beams form th vertical polarization light beams under the action of the Faraday rotator, the th vertical polarization light beams are transmitted through the polarization beam splitter prism, and the focusing mirror splits the second vertical polarization light beams into a plurality of light beams.

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

Preferably, the incident beam is a femtosecond laser having a wavelength of 1030 nm.

Preferably, the half-wave plate has a wavelength of 1030nm and a damage threshold of 10J/cm²A half-wave plate of @10 ns.

Preferably, the polarization beam splitter prism adopts a wavelength of 1030nm and a damage threshold of 7J/cm²@10ns polarization splitting prism.

Preferably, the Faraday rotator has a wavelength range of 1030 + -10 nm and a damage threshold of 10J/cm²An optical rotator of @10 ns.

Preferably, the pure phase type liquid crystal spatial light modulator is a reflective silicon-based liquid crystal spatial light modulator with a high damage threshold and applicable to a wave band of 1000 nm-1100 nm, and compared with a traditional transmission type spatial light modulator, the pure phase type reflective silicon-based liquid crystal spatial light modulator is used for modulating a light field, and the pure phase type reflective silicon-based liquid crystal spatial light modulator has the advantages of high energy utilization rate, high diffraction efficiency, high filling factor and the like.

Preferably, the focusing lens is a field lens with a near infrared light antireflection film plated on the surface and a high damage threshold.

The invention has the beneficial effects that:

1. according to the laser beam splitting device based on the pure-phase spatial light modulator, the phase distribution diagrams corresponding to different beam splitting conditions (the number, the energy distribution, the positions and the like of split beams) are loaded on the spatial light modulator, the phase of an incident beam is modulated, and flexible and controllable control of any light beam after beam splitting is achieved.

2. The spatial light modulator is introduced to encode the high-energy laser and then process the high-energy laser, so that the flexibility and controllability of the light beam are realized, the beam splitting device is simplified, and the laser processing efficiency is greatly improved.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of embodiments of the dynamically controllable laser beam splitting device according to the present invention.

Detailed Description

The present invention is further described in detail below with reference to the attached drawing figures to enable one skilled in the art to practice the invention with reference to the description.

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

In embodiments, as shown in fig. 1, the kinds of dynamically controllable laser beam splitting devices according to the present invention include a half-wave plate 2, a polarization beam splitter prism 4, a faraday rotator 6, a spatial light modulator 8, and a focusing mirror 12, where an incident beam 1 passes through the half-wave plate 2, the polarization beam splitter prism 4, the faraday rotator 6, the spatial light modulator 8, the faraday rotator 6, the polarization beam splitter prism 4, and the focusing mirror 12 in sequence, and finally focuses the split beam on the surface of a workpiece 14 to be processed.

The Faraday rotator 6 adopts a 45-degree Faraday rotator, the incident beam 1 adopts femtosecond laser with the wavelength of 1030nm, and the half-wave plate 2 adopts the femtosecond laser with the wavelength of 1030nm and the damage threshold of 10J/cm²A half-wave plate 2 of @10ns, and the polarization beam splitter 4 adopts a wavelength position of 1030nm and a damage threshold of 7J/cm²A polarizing beam splitter 4 of @10ns, the Faraday rotator 6 having a wavelength range of 1030 +/-10 nm and a damage threshold of 10J/cm²The optical rotator of @10ns, the spatial light modulator 8 is a reflective silicon-based liquid crystal spatial light modulator 8 with a high damage threshold and applicable waveband of 1000 nm-1100 nm, and the focusing mirror 12 adopts a field lens with a near infrared light antireflection film plated on the surface and a high damage threshold.

In embodiments, as shown in fig. 1, the dynamically controllable laser beam splitting device according to the present invention works according to the following principle:

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

the th horizontally polarized light beam 3 is incident to the polarization beam splitter prism 4 and is transmitted completely, and a second horizontally polarized light beam 5 is output;

the second horizontal polarized light beam 5 is incident to a Faraday rotator 6, and under the action of a magneto-optical crystal in the Faraday rotator, an 45-degree polarized light beam 7 with the vibration direction rotated by 45 degrees is transmitted;

the 45 th polarized light beam 7 vertically enters the liquid crystal panel of the liquid crystal on silicon spatial light modulator 8, and after the phase modulation action of the spatial light modulator 8, the second 45 ° polarized light beam 9 and the 45 th polarized light beam 7 are reflected in the vibration direction ;

the second 45-degree polarized light beam 9 is incident to the Faraday rotator 6, the vibration direction of the Faraday rotator is rotated by 45 degrees again, and a -th vertically-polarized light beam 10 is transmitted;

the th vertically polarized light beam 10 is incident to the polarization beam splitter prism 4 and totally reflected, and a second vertically polarized light beam 11 is reflected;

the vertically polarized light beam 11 enters a focusing lens 12, and is emitted to be a split light beam 13 under the action of the focusing lens, and the split light beam 13 is focused on the surface of a workpiece 14 to be processed to process the workpiece.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the specification and the embodiments, but is fully applicable in all kinds of fields adapted for the invention.

Claims

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. The dynamically controllable laser beam splitting device according to claim 1, wherein the Faraday rotator is a 45 ° Faraday rotator.
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. 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. 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. 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. 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. 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.