Optical device and laser processing device

Abstract

The invention discloses an optical device for splitting an input laser pulse into two sub-pulses having an adjustable time interval, the optical device comprising: a polarizer adapted to split the laser pulse into a first polarization component and a second polarization component; and an adjustment unit adapted to reflect at least one of the first polarization component and the second polarization component toward the polarizer and adjust a propagation distance of the at least one of the first polarization component and the second polarization component, and the first polarization component and the second polarization component are combined again through the polarizer to obtain the two sub-pulses. According to certain exemplary embodiments, the optical device for time pulse splitting in the picosecond time scale can be provided, and the optical device is simple and compact in structure, low in cost, high in compatibility and wide in application. The invention further provides a laser processing device with the optical device.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and in particular to an optical device capable of temporally modulating laser pulses within a picosecond time scale and a laser processing device having the optical device. Background Art

[0002] Ultrashort laser pulses have good application effects in the field of precision machining due to their extremely short pulse width and extremely high peak power of a single pulse. Compared with traditional single-pulse machining, the processing mode based on pulse trains can not only obtain better processing quality, but also ensure high processing efficiency. The current laser sources of the prior art can generate pulse sequences with time delays of nanoseconds or hundreds of picoseconds, and the delay time depends on different laser sources and is fixed. In addition, the timing pulse design below 1000 picoseconds has been proven to be beneficial in a variety of processing and research work, such as laser ablation, laser-induced breakdown microscopy, soft X-ray generation, etc. However, due to the complexity of the implementation method, the time delay parameter range below 1000 picoseconds is rarely used in industry. Therefore, a new optical device is needed to easily implement the timing pulse design of this parameter range. Summary of the invention

[0003] An object of the present invention is to provide an optical device and a laser processing device having the optical device, which are capable of temporally modulating laser pulses within a picosecond time scale, so as to at least partially overcome the deficiencies in the prior art.

[0004] According to a first aspect of the present invention, there is provided an optical device, the optical device comprising:

[0005] a polarizer adapted to decompose an input laser pulse into a first polarization component and a second polarization component; and

[0006] An adjustment unit is provided, which is suitable for changing the polarization state, propagation direction and propagation distance of at least one of the first polarization component and the second polarization component, so that the first polarization component and the second polarization component are combined again through the polarizer to obtain the two sub-pulses with a time interval.

[0007] According to an optional embodiment of the present invention, the polarizer is adapted to decompose the laser pulse into a transmitted first polarization component and a reflected second polarization component having polarization states orthogonal to each other.

[0008] According to an optional embodiment of the present invention, the adjustment unit is configured to change the polarization direction of the incident first polarization component and / or the second polarization component and reflect it toward the polarizer.

[0009] According to an optional embodiment of the present invention, the adjustment unit includes a plurality of adjustment components, each of which is configured to change the polarization direction of a corresponding polarization component incident from the polarizer by π / 2 and reflect it back to the polarizer.

[0010] According to an optional embodiment of the present invention, each of the adjustment components includes a quarter wave plate and a reflector arranged along the incident direction of its corresponding polarization component.

[0011] According to an optional embodiment of the present invention, at least the reflector of at least one of the adjustment components is configured as a movable part which can change the distance between the reflector and the polarizer by moving.

[0012] According to an optional embodiment of the present invention, the reflector of at least one of the adjustment components is configured so that its normal axis has a predetermined angle with respect to an incident polarization component, or the reflector is configured as a parabolic reflector with a predetermined focal length.

[0013] According to an optional embodiment of the present invention, the movable part is configured to be movable and positionable relative to the polarizer within a range of 0 to 5000 mm, in particular within a range of 0 to 150 mm.

[0014] According to an optional embodiment of the present invention, the movable part is configured so that the length difference between the optical path of the first polarization component and the optical path of the second polarization component is 0-1000 mm, in particular 60 mm.

[0015] According to an optional embodiment of the present invention, the adjustment unit includes a first adjustment component and a second adjustment component arranged on the optical path of the second polarization component, so that the second polarization component initially reflected off the polarizer is incident on the first adjustment component and reflected back to the polarizer by the first adjustment component, and after transmitting off the polarizer, is incident on the second adjustment component and reflected back to the polarizer by the second adjustment component, and is combined with the first polarization component after being reflected again by the polarizer.

[0016] According to an optional embodiment of the present invention, the adjustment unit includes a first adjustment component and a second adjustment component arranged on the optical path of the first polarization component, so that the first polarization component that is initially transmitted through the polarizer is incident on the first adjustment component and is reflected back to the polarizer by the first adjustment component, and after being reflected through the polarizer, is incident on the second adjustment component and is reflected back to the polarizer by the second adjustment component, and is combined with the second polarization component after being transmitted again by the polarizer.

[0017] According to an optional embodiment of the present invention, the adjustment unit includes a first adjustment component arranged on the optical path of the first polarization component and a second adjustment component arranged on the optical path of the second polarization component, so that the first polarization component initially transmitted from the polarizer is incident on the first adjustment component and reflected back to the polarizer by the first adjustment component and reflected by the polarizer, and the second polarization component initially reflected from the polarizer is incident on the second adjustment component and reflected back to the polarizer by the second adjustment component and transmitted by the polarizer to be combined with the first polarization component reflected by the polarizer.

[0018] According to an optional embodiment of the present invention, the polarizer is a polarization beam splitter cube, in particular, the side length is approximately 30 mm, in particular the refractive index is 1.4 to 1.6, preferably 1.5.

[0019] According to an optional embodiment of the present invention, an optical 4f device is arranged in the optical path of the first polarization component or the second polarization component.

[0020] According to a second aspect of the present invention, a laser processing device is provided, which includes: at least one laser radiation source providing laser pulses; an optical device according to the first aspect of the present invention optically connected to the laser radiation source; and a focusing module for applying laser light from the optical device to a workpiece to be processed.

[0021] According to an optional embodiment of the present invention, the at least one laser radiation source is an ultrashort pulse laser, in particular a femtosecond laser and / or a picosecond laser and / or a nanosecond laser.

[0022] According to an optional embodiment of the present invention, the optical device is configured to be suitable for generating a pulse delay of 0 to 20 ns, in particular 0 to 1000 ps.

[0023] According to an optional embodiment of the present invention, the focusing module includes a reflector, a beam shaping unit, a lens group and / or a scanning mirror.

[0024] According to an optional embodiment of the present invention, the pulse duration generated by the laser radiation source is 100fs to 1000ps.

[0025] According to an optional embodiment of the present invention, the wavelength range of the laser pulse output by the laser radiation source is 200nm to 2000nm, in particular, 1030±30nm.

[0026] According to an optional embodiment of the present invention, a beam configuration module is provided between the laser radiation source and the optical device, which is suitable for configuring the propagation angle, divergence, beam diameter and / or polarization state of the laser pulse.

[0027] According to an optional embodiment of the present invention, the laser processing device is a laser ablation device, a laser cutting device, a laser drilling device, a laser induced breakdown spectrometer, a soft X-ray generating device, a surface treatment device or a surface cleaning device.

[0028] According to certain exemplary embodiments of the present invention, an optical device for performing time pulse splitting within a picosecond time scale can be provided, and the optical device has a simple and compact structure, low cost, strong compatibility and wide application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0030] Figure 1 shows the main parts of an optical device according to an exemplary embodiment of the present invention;

[0031] Figure 2A and Figure 2B An optical device according to an exemplary embodiment of the present invention is shown, and propagation paths of each polarization component are shown respectively;

[0032] Figure 3A and Figure 3B An optical device according to another exemplary embodiment of the present invention is shown, and propagation paths of each polarization component are respectively shown;

[0033] Figure 4A and Figure 4B An optical device according to another exemplary embodiment of the present invention is shown, and propagation paths of each polarization component are respectively shown;

[0034] Figure 5 A main part of a laser processing apparatus according to an exemplary embodiment of the present invention is shown. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the scope of protection of the present invention. In addition, for the sake of clarity, some figure marks are omitted in some drawings, which certainly does not mean that the corresponding embodiments do not include the unmarked parts.

[0036] Figure 1 FIG. 1 shows the main parts of an optical device 1 according to an exemplary embodiment of the present invention. Figure 1As shown, an optical device 1 according to an exemplary embodiment of the present invention includes a polarizer 11, which is suitable for decomposing a laser pulse into a first polarization component and a second polarization component; and an adjustment unit 12, which is suitable for changing the polarization state, propagation direction and propagation distance of at least one of the first polarization component and the second polarization component, so that the first polarization component and the second polarization component are combined again through the polarizer 11 to obtain two sub-pulses with a time interval.

[0037] like FIG. 2A to FIG. 4B As shown, the polarizer 11 is, for example, a polarization beam splitter cube or a polarization beam splitter prism, which is a substantially symmetrical optical device, and the side length a is preferably approximately 30 mm, and the refractive index n can be 1.4 to 1.6, preferably selected as n=1.5. The polarizer 11 can decompose the laser pulse into a transmitted first polarization component, i.e., a p-polarized beam, and a reflected second polarization component, i.e., an s-polarized beam, having polarization states orthogonal to each other. In other words, the p-polarized component contained in the laser pulse becomes an independent p-polarized beam after being transmitted through the polarizer 11, as shown in FIG. Figure 2A As shown; the s-polarized component contained in the laser pulse becomes an independent s-polarized beam after being reflected by the polarizer 11, as shown Figure 3A As shown, the s-polarized light beam is preferably reflected at an angle of 45 degrees, so that its exit direction is substantially at an angle of 90 degrees to the transmitted p-polarized light beam, thereby constructing an optical path in which the propagation directions of the first polarization component and the second polarization component are different. The adjustment unit 12 is arranged on the optical path of at least one of the first polarization component and the second polarization component, and changes the polarization state of the corresponding polarization component and reflects it toward the polarizer 11, and can adjust the propagation distance of the corresponding polarization component, so that the two polarization components finally combined by the polarizer 11 have a time delay with each other due to different propagation distances, so that two sub-pulses with a time interval can be obtained.

[0038] Specifically, the adjustment unit 12 includes a plurality of adjustment components (for example, two adjustment components 120a and 120b in the example of the attached figure), each of which is configured to change the polarization direction of the incident corresponding polarization component from the polarizer 11 by π / 2 and reflect it back to the polarizer 11. More specifically, each adjustment component includes a quarter wave plate 121 and a reflector 122 arranged along the incident direction of its corresponding polarization component, and the p-polarized light beam or the s-polarized light beam incident on the corresponding adjustment component reaches the reflector 122 via the quarter wave plate 121, and passes through the quarter wave plate 121 again after being reflected by the reflector 122, so that the polarization direction of the p-polarized light beam or the s-polarized light beam that passes through the quarter wave plate 121 twice is rotated by π / 2 to become an s-polarized light beam or a p-polarized light beam, and is emitted from the adjustment component toward the polarizer 11 again, and is reflected or transmitted by the polarizer 11 again. Among them, at least the reflector 122 of at least one adjustment component is configured as a movable part, which can change the distance between it and the polarizer 11 by moving, thereby changing the propagation distance of the corresponding polarization component, that is, the optical path length. Optionally, at least one adjustment component can be moved and positioned relative to the polarizer 11 as a whole as a movable part. Alternatively, it can also be configured so that each adjustment component is a movable part or has a movable part, so that the propagation distance of the corresponding polarization component can be adjusted more flexibly.

[0039] By using the adjustment unit 12 to change the polarization state of the corresponding polarization component and allowing the polarization component with the changed polarization state to be incident on the polarizer 11 again, and simultaneously changing the propagation distance of the corresponding polarization component, a propagation path with adjustable length of the laser pulse can be constructed within a small spatial size by utilizing the size of the polarizer 11 itself, so that the optical path length difference of the two polarization components can be adjusted with a higher resolution by utilizing a more compact structure, thereby achieving more precise time modulation of the laser pulse. This will be described in detail below in conjunction with specific embodiments.

[0040] like Figure 2A and Figure 2B As shown, according to an exemplary embodiment of the present invention, the adjustment unit 12 includes a first adjustment component 120a and a second adjustment component 120b arranged on the optical path of the second polarization component, wherein the distance between the reflecting surface of the reflector 122 of the first adjustment component 120a and the polarizer 11 is D1, and the distance between the reflecting surface of the reflector 122 of the second adjustment component 120b and the polarizer 11 is D2.

[0041] like Figure 2A As shown, the p-polarized beam ( FIG. 2A to FIG. 4B The p-polarized light beam (in the figure, the dotted line indicates that the p-polarized light beam) can be transmitted through the polarizer 11 and basically propagate along the original light path. The propagation distance L1 through the optical device 1 is:

[0042] L1=a×1×n,

[0043] As mentioned above, n is the refractive index of the polarizer 11 , and a is the side length of the polarizer 11 .

[0044] like Figure 2B As shown, the s-polarized beam ( FIG. 2A to FIG. 4B The s-polarized light beam (indicated by solid lines in the figure) is reflected by the polarizer 11, so that the optical path changes clockwise by approximately 90 degrees and enters the first adjustment component 120a. The s-polarized light beam is reflected by the reflector 122 in the first adjustment component 120a, and the polarization direction is rotated by π / 2 after passing through the quarter-wave plate 121 twice, so that it becomes a p-polarized light beam and enters the polarizer 11 again and is transmitted. Then, the p-polarized light beam as the second polarization component transmitted out of the polarizer 11 enters the second adjustment component 120b again, and is reflected by the reflector 122 in the second adjustment component 120b, and the polarization direction is rotated by π / 2 after passing through the quarter-wave plate 121 twice, so that it enters the polarizer 11 again as an s-polarized light beam and is reflected again. The propagation direction of the s-polarized light beam as the second polarization component that is reflected by the polarizer 11 this time and emitted thereby is substantially the same as the propagation direction of the optical path of the laser pulse that originally entered the polarizer 11, so that it can be combined with the transmitted p-polarized light beam as the first polarization component. The propagation distance L2 of the second polarization component passing through the first adjustment component 120a and the second adjustment component 120b through the optical device 1 is:

[0045] L2=a×3×n+D1×2+D2×2.

[0046] The time interval TD between the first polarization component and the second polarization component of the combined beam is:

[0047] TD = (L2 – L1) / c, where c is the speed of light in vacuum.

[0048] Thus, one laser pulse can be split into two sub-pulses with a time interval TD.

[0049] The values ​​of the distances D1 and D2 can be set arbitrarily according to the actual requirements for the time interval TD, for example, they can be selected from the range of 0 to 5000 mm, especially 0 to 150 mm. To this end, each adjustment component or its movable part is configured to be able to move and position relative to the polarizer 11 at least within this range, for example, by means of a sliding module such as a slide rail.

[0050] According to the optical device 1 of this embodiment, by appropriately selecting values ​​for each parameter, the time interval TD between two sub-pulses can reach about 300 picoseconds, and can easily reach 1000 picoseconds. In addition, the optical device 1 according to this embodiment does not substantially change the propagation direction of the original laser pulse, and thus can be equivalent to an optical window or an optical mirror, and due to its compact structural size, it is easy to be directly integrated into various existing optical systems, and has strong compatibility and applicability.

[0051] like Figure 3A and Figure 3B As shown, according to another exemplary embodiment of the present invention, the adjustment unit 12 includes a first adjustment component 120a and a second adjustment component 120b arranged on the optical path of the first polarization component, wherein the distance between the reflecting surface of the reflector 122 of the first adjustment component 120a and the polarizer 11 is D1, and the distance between the reflecting surface of the reflector 122 of the second adjustment component 120b and the polarizer 11 is D2.

[0052] like Figure 3A As shown, the s-polarized light beam as the second polarization component in the laser pulse incident on the polarizer 11 can be reflected by the polarizer 11 so that the optical path is changed by approximately 90 degrees, and its propagation distance through the optical device 1 is:

[0053] L2=a×1×n.

[0054] like Figure 3B As shown, the p-polarized light beam as the first polarization component in the same laser pulse is transmitted through the polarizer 11 and incident on the first adjustment component 120a. In the first adjustment component 120a, it is reflected by the reflector 122 and passes through the quarter-wave plate 121 twice, and the polarization direction is rotated by π / 2, thereby becoming an s-polarized light beam and incident on the polarizer 11 again and further reflected. Then, the first polarization component reflected from the polarizer 11 and as an s-polarized light beam is incident on the second adjustment component 120b again. In the second adjustment component 120b, it is reflected by the reflector 122 and passes through the quarter-wave plate 121 twice, and the polarization direction is rotated by π / 2 again, thereby incident on the polarizer 11 again as a p-polarized light beam and is transmitted again. After this transmission, the first polarization component as a p-polarized light beam can be combined with the reflected second polarization component as an s-polarized light beam. The propagation distance of the first polarization component passing through the first adjustment component 120a and the second adjustment component 120b is:

[0055] L1=a×3×n+D1×2+D2×2.

[0056] There is a time interval between the first polarization component and the second polarization component of the combined beam:

[0057] TD=(L1–L2) / c.

[0058] and Figure 2A and Figure 2B Similar to the embodiment shown, the optical device 1 according to this embodiment can also split a laser pulse into two sub-pulses with a time interval TD, and the time interval TD can be appropriately adjusted by appropriately setting values ​​for various parameters. Figure 2A and Figure 2B What is different from the embodiment shown is that the optical device 1 according to this embodiment can change the propagation direction of the laser pulse by a specific angle, such as the change of approximately 90 degrees as mentioned above. Therefore, it can also be cleverly applied to many optical path designs due to its function as a reflector, which helps to further reduce the number of optical devices in the corresponding optical path design and make the corresponding optical path arrangement compact.

[0059] like Figure 4A and Figure 4B As shown, according to another exemplary embodiment of the present invention, the adjustment unit 12 includes a first adjustment component 120a arranged on the optical path of the first polarization component and a second adjustment component 120b arranged on the optical path of the second polarization component, wherein the distance between the reflecting surface of the reflector 122 of the first adjustment component 120a and the polarizer 11 is D1, and the distance between the reflecting surface of the reflector 122 of the second adjustment component 120b and the polarizer 11 is D2.

[0060] like Figure 4A As shown, the p-polarized light beam as the first polarization component in the laser pulse incident on the polarizer 11 is transmitted through the polarizer 11 and incident on the first adjustment component 120a. In the first adjustment component 120a, it is reflected by the reflector 122 and passes through the quarter-wave plate 121 twice, and the polarization direction is rotated by π / 2, thereby becoming an s-polarized light beam and incident on the polarizer 11, and reflected by the polarizer 11. Its propagation distance through the optical device 1 is:

[0061] L1=a×2×n+D1×2.

[0062] like Figure 4B As shown, the s-polarized light beam as the second polarization component in the same laser pulse is reflected by the polarizer 11, so that the optical path changes by approximately 90 degrees and enters the second adjustment component 120b. The s-polarized light beam is reflected by the reflector 122 in the second adjustment component 120b and the polarization direction is rotated by π / 2 after passing through the quarter-wave plate 121 twice, thereby becoming a p-polarized light beam and entering the polarizer 11, and is transmitted through the polarizer 11 and combined with the first polarization component as the s-polarized light beam after reflection. The propagation distance of the second polarization component through the optical device 1 is:

[0063] L2=a×2×n+D2×2.

[0064] There is a time interval between the first polarization component and the second polarization component of the combined beam:

[0065] TD=(L1–L2) / c.

[0066] According to the optical device 1 of this embodiment, by appropriately selecting the values ​​of D1 and D2 within the range described above, the propagation distances of the first polarization component and the second polarization component can be adjusted, so that a wider range of time intervals between sub-pulses can be obtained by means of the optical device 1 of this embodiment, which is estimated to be -1300 picoseconds to 1300 picoseconds, so it can achieve a more flexible design of timing pulses and is more practical. Figure 3A and Figure 3B Similar to the embodiment shown, it can also change the propagation direction of the laser pulse, for example, by approximately 90 degrees, and therefore also has the function of a reflector and can be cleverly applied to many optical path designs to obtain similar effects.

[0067] Preferably, in each of the above exemplary embodiments, the movable part of the adjustment assembly can be configured so that the length difference between the optical path of the first polarization component and the optical path of the second polarization component is 0 to 1000 mm, in particular 60 mm. In the case of a short optical path length difference of, for example, 60 mm, there will not be a large difference in the divergence of the two polarization components, so a collimated output light beam can still be obtained. In the case of a longer optical path length difference in which the problem of beam divergence must be considered, for example, a known optical 4f device can be inserted into one of the optical paths to compensate for the beam divergence.

[0068] In the optical device 1 according to various exemplary embodiments of the present invention, spatially modulated laser sub-pulses can be additionally obtained by appropriately configuring the polarizer 11 and / or the reflector 122 of the adjustment component. For example, the polarizer 11 can be set to have a small angle, that is, it can change the propagation direction of the reflected second polarization component by a small deviation from 90 degrees, thereby obtaining two sub-pulses with a small angle deviation. The reflector 122 of a specific adjustment component can also be set as needed so that its normal axis has a predetermined angle relative to the incident polarization component, which can also obtain two sub-pulses with a small angle deviation. Or the reflector 122 of a specific adjustment component can be configured as a curved reflector with a long focal length (including a parabolic reflector and a spherical reflector), so that the two sub-pulses will have different divergences and can be focused to different positions.

[0069] The optical device 1 according to each exemplary embodiment of the present invention is composed of only simple optical devices, is strong and stable, has a compact structure, occupies a small space, and as an adjustable optical device, can be easily configured to obtain a time-modulated pulse sequence with a time delay of 0 to 1000 picoseconds. For example, if the required time delay is 0 to 400 picoseconds, the size of the optical device 1 can be less than 100×100×50 mm 3 , and can even be smaller than 50×50×50mm 3 . In addition, the optical device 1 according to each exemplary embodiment of the present invention splits the pulse only by refraction and reflection for time modulation, which is functionally similar to an optical window or an optical mirror, and causes almost no energy loss to the laser pulse. The optical device 1 according to each exemplary embodiment of the present invention having the above advantages is compatible with various lasers, especially femtosecond and picosecond lasers, and is easy to be integrated into various existing laser equipment, and the picosecond pulse sequence obtained by the optical device 1 is efficient and beneficial for a variety of laser processing.

[0070] According to another aspect of the present invention, there is provided a laser processing device 100 having an optical device 1 according to any exemplary embodiment of the present invention, which also includes at least one laser radiation source 2 for providing laser pulses and a focusing module 3 for applying the laser pulses from the optical device 1 to a workpiece to be processed.

[0071] Preferably, the laser radiation source 2 is an ultrashort pulse laser capable of providing ultrashort pulses with a duration of, for example, 100 femtoseconds to 1000 picoseconds, and the wavelength of the laser pulse outputted by the laser source is in the range of 200nm to 2000nm, in particular, 1030±30nm.

[0072] As described above, the optical device 1 can be used to easily configure a pulse delay of 0 to 1000 picoseconds. Of course, a pulse delay of, for example, 0 to 20 nanoseconds can also be configured as needed, and the original optical path of the pulse can be changed or not as needed.

[0073] The focusing module 3 may be selectively composed of a reflector, a beam shaping unit, a lens group and / or a scanning mirror, and is configured to guide and focus the time-modulated pulse sequence obtained by the optical device 1 to a target position of the workpiece to be processed in a desired manner.

[0074] In a preferred embodiment, a beam configuration module 4 may be provided between the laser radiation source 2 and the optical device 1, and the beam configuration module 4 may configure the propagation angle, divergence, beam diameter and / or polarization state of the laser pulse to be incident on the optical device 1. That is, various characteristic parameters of the laser pulse to be input to the optical device 1 may be configured in advance by the beam configuration module 4, for example, the two polarization components may be pre-configured so that the two polarization components have different energy ratios, so that separated sub-pulses with different energy ratios are subsequently obtained through the optical device 1, which may be easily achieved by conventional methods such as a half-wave plate and a polarizer.

[0075] Through appropriate configuration, the laser processing device 100 according to each exemplary embodiment of the present invention can be applied to processing various materials in various ways, such as ablation, cutting, drilling, surface treatment, cleaning and other processing of various materials, chamfering edge cutting of glass, generation of X-rays, etc. It can be seen that the configuration examples of the laser processing device 100 according to each exemplary embodiment of the present invention include a laser ablation device, a laser cutting device, a laser drilling device, a laser induced breakdown spectrometer, a soft X-ray generation device, a surface treatment device or a surface cleaning device, etc.

[0076] For those skilled in the art, it is obvious that the technical concept of the present invention is not limited to laser welding of lithium battery shells, but can also be used to weld structures of any other shape. At the same time, it is not limited to a fully enclosed arrangement, but can also be adjusted according to actual welding needs.

[0077] Although specific embodiments of the present invention are described in detail herein, they are provided for the purpose of explanation only and should not be considered to limit the scope of the present invention. Various substitutions, changes and modifications may also be conceived without departing from the spirit and scope of the present invention.

Claims

1. An optical device (1), comprising: A polarizer (11) adapted to decompose an input laser pulse into a first polarization component and a second polarization component; and An adjustment unit (12) is suitable for changing the polarization state, propagation direction and propagation distance of at least one of the first polarization component and the second polarization component, so that the first polarization component and the second polarization component are combined again through the polarizer (11) to obtain the two sub-pulses with a time interval.

2. The optical device (1) according to claim 1, wherein: The polarizer (11) is suitable for decomposing the laser pulse into a transmitted first polarization component and a reflected second polarization component having polarization states orthogonal to each other; and / or The adjustment unit (12) is configured to change the polarization direction of the incident first polarization component and / or the second polarization component and reflect it toward the polarizer (11).

3. The optical device (1) according to claim 1 or 2, wherein: The adjustment unit (12) comprises a plurality of adjustment components, each of which is configured to change the polarization direction of a corresponding polarization component incident from the polarizer (11) by π / 2 and reflect it back to the polarizer (11).

4. The optical device (1) according to claim 3, wherein: Each of the adjustment components comprises a quarter wave plate (121) and a reflector (122) arranged along the incident direction of its corresponding polarization component.

5. The optical device (1) according to claim 4, wherein: At least one of the reflectors (122) of at least one of the adjustment components is configured as a movable part capable of changing the distance between the reflector and the polarizer (11) by moving; and / or The reflector (122) of at least one of the adjustment components is configured such that its normal axis has a predetermined angle relative to an incident polarization component, or the reflector (122) is configured as a parabolic reflector (122) with a predetermined focal length.

6. The optical device (1) according to claim 5, wherein: The movable part is configured to be movable and positionable relative to the polarizer (11) within a range of 0 to 5000 mm, in particular within a range of 0 to 150 mm; and / or The movable part is configured so that a length difference between an optical path of the first polarization component and an optical path of the second polarization component is 0 to 1000 mm, in particular, 60 mm.

7. The optical device (1) according to any one of claims 1 to 6, wherein: The adjustment unit (12) comprises a first adjustment component (120a) and a second adjustment component (120b) arranged on the optical path of the second polarization component, so that the second polarization component initially reflected from the polarizer (11) is incident on the first adjustment component (120a) and is reflected back to the polarizer (11) by the first adjustment component (120a), and after being transmitted from the polarizer (11), is incident on the second adjustment component (120b) and is reflected back to the polarizer (11) by the second adjustment component (120b), and is combined with the first polarization component after being reflected again by the polarizer (11).

8. The optical device (1) according to any one of claims 1 to 6, wherein: The adjustment unit (12) comprises a first adjustment component (120a) and a second adjustment component (120b) arranged on the optical path of the first polarization component, so that the first polarization component initially transmitted through the polarizer (11) is incident on the first adjustment component (120a) and is reflected back to the polarizer (11) by the first adjustment component (120a), and after being reflected from the polarizer (11), is incident on the second adjustment component (120b) and is reflected back to the polarizer (11) by the second adjustment component (120b), and is combined with the second polarization component after being transmitted again by the polarizer (11).

9. The optical device (1) according to any one of claims 1 to 6, wherein: The adjustment unit (12) comprises a first adjustment component (120a) arranged on the optical path of the first polarization component and a second adjustment component (120b) arranged on the optical path of the second polarization component, so that the first polarization component initially transmitted from the polarizer (11) is incident on the first adjustment component (120a) and is reflected back to the polarizer (11) by the first adjustment component (120a) and is reflected by the polarizer (11), and the second polarization component initially reflected from the polarizer (11) is incident on the second adjustment component (120b) and is reflected back to the polarizer (11) by the second adjustment component (120b) and is transmitted by the polarizer (11) and combined with the first polarization component reflected by the polarizer (11).

10. The optical device (1) according to any one of claims 1 to 6, wherein: The polarizer (11) is a polarization beam splitter cube, in particular with a side length of approximately 30 mm, in particular with a refractive index of 1.4 to 1.6, preferably 1.5; and / or An optical device is arranged in the optical path of the first polarization component or the second polarization component.

11. A laser processing device (100), comprising: at least one laser radiation source (2) providing laser pulses; An optical device (1) according to any one of claims 1 to 10 optically connected to the laser radiation source (2); and A focusing module (3) is used for applying the laser light from the optical device (1) to a workpiece to be processed.

12. The laser processing device (100) according to claim 11, wherein: The at least one laser radiation source (2) is an ultrashort pulse laser, in particular a femtosecond laser and / or a picosecond laser and / or a nanosecond laser; and / or The optical device (1) is configured to be suitable for generating a pulse delay of 0 to 20 ns, in particular 0 to 1000 ps; and / or The focusing module (3) comprises a reflector (122), a beam shaping unit, a lens group and / or a scanning mirror.

13. The laser processing device (100) according to claim 11 or 12, wherein: The pulse duration generated by the laser radiation source (2) is 100 fs to 1000 ps; and / or The wavelength range of the laser pulse output by the laser radiation source (2) is 200 nm to 2000 nm, in particular 1030 ± 30 nm; and / or A beam configuration module (4) is arranged between the laser radiation source (2) and the optical device (1), which is suitable for configuring the propagation angle, divergence, beam diameter and / or polarization state of the laser pulse.

14. The laser processing device (100) according to any one of claims 11 to 13, wherein: The laser processing device (100) is a laser ablation device, a laser cutting device, a laser drilling device, a laser induced breakdown spectrometer, a soft X-ray generating device, a surface treatment device or a surface cleaning device.

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