Independently controllable laser time-sharing and light-sharing optical path, laser processing system and method

Abstract

The present invention provides an independently controllable laser time-sharing and light-splitting system, comprising a laser light source, at least two light-splitting optical paths and a digital pulse delay generator; each light-splitting optical path comprises an electro-optic modulator and a polarization beam splitter, and each light-splitting optical path is arranged in sequence; the laser light source emits a laser pulse of a certain frequency, which passes through the electro-optic modulator and the polarization beam splitter of the first to the last light-splitting optical paths in sequence, and the electro-optic modulator splits part of the laser pulse and outputs it from the polarization beam splitter; the digital pulse delay generator is used to trigger the laser pulse, set the frequency of the laser pulse, and the frequency and delay of the electro-optic modulator of each light-splitting optical path. The present invention utilizes an electro-optic modulator and a polarization beam splitter to realize the beam splitting of the laser, while each light-splitting optical path is independent of each other, solving the problem that the traditional light-splitting optical path cannot process different graphics, and the light paths after the light splitting affect each other, resulting in low processing efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser spectrometry, and in particular relates to an independently controllable laser time-sharing and spectrometry system, a laser processing system and a method. Background Art

[0002] Laser splitting includes power splitting and time splitting. The frequency of the laser can be split in time using an electro-optic modulator, which is a time splitting technology. Chinese invention patent CN103042305A discloses a method for time splitting using an electro-optical device. This method can split the laser in frequency, but after splitting, the switches of the two lasers cannot be independently controlled. Different graphics cannot be processed using this splitting optical path. When the same graphics are processed using this splitting optical path, there will also be a problem of asynchronous delays of the two lasers, which will affect the processing quality and efficiency. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a laser time-sharing and light-sharing system, a laser processing system and a method which can be independently controlled without affecting each other.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: an independently controllable laser time-sharing and light-splitting system, characterized in that: it includes a laser light source, at least two light-splitting optical paths and a digital pulse delay generator; wherein each light-splitting optical path includes an electro-optical modulator and a polarization beam splitter, and the light-splitting optical paths are arranged in sequence; the laser light source emits a laser pulse of a certain frequency, which passes through the electro-optical modulator and the polarization beam splitter of the first to the last light-splitting optical paths in sequence, and part of the laser pulse is separated by the electro-optical modulator and output from the polarization beam splitter; the digital pulse delay generator is used to trigger the laser pulse, set the frequency of the laser pulse, and the frequency and delay of the electro-optical modulator of each light-splitting optical path.

[0005] According to the above scheme, the digital pulse delay generator is at a frequency of f Trigger the laser pulse and set the sum of the frequencies of the electro-optic modulators of each split optical path to be less than or equal to f , and a delay is provided between the signals of each split light path so that the laser pulse is not repeatedly divided into the split light paths.

[0006] According to the above scheme, it also includes a trigger controller for providing a trigger signal to each electro-optical modulator to trigger the switch of the electro-optical modulator. The electro-optical modulator performs light splitting under the combined action of the trigger signal and the frequency control of the digital pulse delay generator.

[0007] According to the above scheme, a phase delay device is also provided between the laser light source and the first split light path.

[0008] According to the above scheme, the time-sharing and light-splitting system further includes a beam cutoff device, which is arranged at the rear end of the last light-splitting optical path and is used to absorb the laser pulses that are not split.

[0009] A laser processing system, characterized in that: the system includes the independently controllable laser time-sharing and light-splitting system; the laser pulses output by each light-splitting optical path are respectively used as a processing optical path for laser processing, and each processing optical path is equipped with a corresponding controller for controlling the processing path and the switch of the electro-optical modulator; according to the laser processing timing corresponding to each processing optical path, the digital pulse delay generator sets the frequency for the laser light source and the electro-optical modulator of each light-splitting optical path, and the controller sends a trigger signal to the electro-optical modulator of the corresponding processing optical path.

[0010] According to the above system, the digital pulse delay generator sets the frequency of the laser light source to f , set the frequency of the electro-optic modulator of each split optical path to f / n, n is the total number of split light paths, and the signal start time of the next split light path differs from that of the previous split light path by 1 laser pulse cycle 1 / f .

[0011] According to the above system, the processing graphics corresponding to each processing optical path are the same; the period at which each controller sends a trigger signal to the electro-optical modulator of the corresponding processing optical path is also the same; when the corresponding processing optical path is being processed, the trigger signal sent by the controller is a high level; when the corresponding processing optical path is not being processed, the trigger signal sent by the controller is a low level.

[0012] According to the above system, the digital pulse delay generator sets the frequencies of the laser light source and the electro-optic modulators of each split light path to be f ; Each processing light path corresponds to a processing station, and only one processing station is processed at a time; when the corresponding processing light path is being processed, the trigger signal issued by the controller is a high level; when the corresponding processing light path is not being processed, the trigger signal issued by the controller is a low level.

[0013] According to the above system, the processing station also includes an electric processing platform for realizing two-dimensional or three-dimensional movement, driving the processing workpiece thereon to move according to a preset processing pattern, thereby completing the processing.

[0014] According to the above system, a galvanometer scanning system is also provided at the end of each processing optical path to scan and process the optical path according to a preset processing pattern of the workpiece. Specifically, the galvanometer scanning system includes a galvanometer and a field lens.

[0015] The laser processing method implemented by the laser processing system is characterized in that: the laser light from the same laser light source is distributed to several split light paths, the frequency of the laser light source and the electro-optical modulator of each split light path is set by a digital pulse delay generator, and at the same time, the marking control card sends a trigger signal to the electro-optical modulator of the corresponding processing light path to realize independent control of each split light path; the specific settings of the digital pulse delay generator and the marking control card are determined according to the laser processing timing corresponding to each processing light path.

[0016] The beneficial effects of the present invention are as follows: while utilizing an electro-optic modulator and a polarization beam splitter to realize laser beam splitting, each split optical path after splitting is controlled by a digital pulse delay generator on its own electro-optic modulator, and is independent of each other and does not interfere with each other; thereby solving the problem in traditional splitting schemes that the split optical paths cannot process different graphics, and the problem that the optical paths after splitting affect each other and reduce the processing efficiency. While making full use of the laser pulse, independent control of each branch optical path is achieved, thereby improving the processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the optical splitting system according to the first embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of a laser processing system according to Embodiment 1 of the present invention.

[0019] Figure 3 This is a timing logic diagram of the first embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of a laser processing system according to Embodiment 1 of the present invention.

[0021] Figure 5 This is a schematic diagram of the structure of another laser processing system according to the first embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the structure of a laser processing system according to the second embodiment of the present invention.

[0023] Figure 7 This is a timing logic diagram of the second embodiment of the present invention.

[0024] Figure 8 This is a timing logic diagram of the third embodiment of the present invention.

[0025] Fig. 9This is a timing logic diagram of the fourth embodiment of the present invention. In the figure: 1-laser light source, 2-half-wave plate, 3-1-first electro-optic modulator, 3-2-second electro-optic modulator, 3-3-third electro-optic modulator, 4-1-first polarization beam splitter, 4-2-second polarization beam splitter, 4-3-third polarization beam splitter, 5-beam cutoff, 6-1-first split light path laser, 6-2-second split light path laser, 6-3-third split light path laser, 7-digital pulse delay generator, 8-1-first marking control card, 8-2-second marking control card, 8-3-third marking control card, 9-1-first electric platform, 9-2-second electric platform, 10-1-first galvanometer scanning system, 10-2, second galvanometer scanning system. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with specific examples and drawings.

[0027] Embodiment 1:

[0028] This embodiment provides a laser time-sharing and light-sharing system that can be independently controlled, such as Figure 1 As shown, it includes a laser light source 1, a half-wave plate 2, two split light paths, a beam cutoff 5 and a digital pulse delay generator 7; wherein the first split light path includes a first electro-optic modulator 3-1 and a first polarization beam splitter 4-1, and the second split light path includes a second electro-optic modulator 3-2 and a second polarization beam splitter 4-2, and the two split light paths are arranged in sequence; the laser light source emits a laser pulse of a certain frequency which passes through the first electro-optic modulator 3-1, the first polarization beam splitter 4-1, the second electro-optic modulator 3-2 and the second polarization beam splitter 4-2 in sequence, and the first polarization beam splitter 4-1 outputs the first split light path laser 6-1, and the second polarization beam splitter 4-2 outputs the second split light path laser 6-2, and finally the laser pulse that is not split is absorbed by the beam cutoff 5; the digital pulse delay generator 7 is used to set the frequency of the laser light source 1, as well as the frequency and delay of the first electro-optic modulator 3-1 and the second electro-optic modulator 3-2. In this embodiment, the beam cutoff 5 is a light blocking tube. The half-wave plate 2 is used to adjust the polarization direction of the laser, and other phase delay devices with the same or similar functions may also be used.

[0029] This embodiment also provides a laser processing system and a processing method. Figure 2As shown, the system includes the above-mentioned independently controllable laser time-sharing and light-splitting system; the first light-splitting optical path laser 6-1 and the second light-splitting optical path laser 6-2 are respectively used as a processing optical path for laser processing, and each processing optical path is equipped with a corresponding marking control card, namely the first marking control card 8-1 and the second marking control card 8-2. According to the laser processing timing corresponding to each processing optical path, the digital pulse delay generator 7 triggers the laser pulse of the laser light source 1, and sets the frequency of the first electro-optical modulator 3-1 and the second electro-optical modulator 3-2. At the same time, the first marking control card 8-1 sends a trigger signal to the switch of the first electro-optical modulator 3-1, and the second marking control card 8-2 sends a trigger signal to the switch of the second electro-optical modulator 3-2. The marking control card can also be replaced by other controllers for controlling the processing path and the switch of the electro-optical modulator.

[0030] In this embodiment, the digital pulse delay generator 7 is Stanford SRS DG535, which can output multi-channel pulse delay signals and has a time resolution of picoseconds; the marking control card adopts RTC5.

[0031] Connect the T0 end of the digital pulse delay generator 7 to the laser light source 1 to provide a trigger signal to the laser light source 1. Connect the T1 and T2 ends of the digital pulse delay generator 7 to the first electro-optical modulator 3-1 and the second electro-optical modulator 3-2 respectively to input pulse modulation signals to the first electro-optical modulator 3-1 and the second electro-optical modulator 3-2. Connect the signals of the first marking control card 8-1 and the second marking control card 8-2 to the first electro-optical modulator 3-1 and the second electro-optical modulator 3-2 respectively.

[0032] Digital pulse delay generator with frequency f To trigger the laser pulse, the frequency of the electro-optic modulator of each split optical path is set according to the principle that the sum of the frequencies of the electro-optic modulators of each split optical path is less than or equal to f , and a delay is provided between the signals of each split light path so that the laser pulse is not repeatedly divided into the split light paths.

[0033] In this embodiment, the reflection and transmission logic sequence of the laser pulse is as follows: Figure 3 As shown. Set the frequency of laser light source 1 to f , the frequencies of the first electro-optic modulator 3-1 and the second electro-optic modulator 3-2 are f / 2, and at the same time, there is a 1 / between the frequencies of the first electro-optical modulator 3-1 and the second electro-optical modulator 3-2. f Time difference.

[0034] When the first marking control card 8-1 outputs a high level, the first electro-optic modulator 3-1 changes the polarization state of the laser, the laser beam is reflected on the first polarization beam splitter 4-1, and the laser beam 6-1 of the first split light path is output; when the first marking control card 8-1 outputs a low level, the laser beam is transmitted through the first polarization beam splitter 4-1, and this part of the transmitted light is not affected by the second electro-optic modulator 3-2 and is directly collected by the beam cutoff 5. When the second marking control card 8-2 outputs a high level, the second electro-optic modulator 3-2 changes the polarization state of the laser, the laser beam is reflected on the second polarization beam splitter 4-2, and the laser beam 6-2 of the second split light path is output; when the second marking control card 8-2 outputs a low level, the laser beam is transmitted through the second polarization beam splitter 4-2 and is directly collected by the beam cutoff 5.

[0035] See also Figure 4 Furthermore, the processing station also includes an electric processing platform. The first electric processing platform 9-1 and the second electric platform 9-2 correspond to the corresponding processing stations respectively, so as to realize two-dimensional or three-dimensional movement, and drive the processing parts thereon to move according to the preset processing pattern, thereby completing the processing.

[0036] Alternatively, see Figure 5 A galvanometer scanning system is also provided at the end of each processing optical path. The first galvanometer scanning system 10-1 and the second galvanometer scanning system 10-2 correspond to the corresponding laser optical paths, respectively, to scan and process the optical paths according to the preset processing patterns of the workpiece. Specifically, the galvanometer scanning system includes a galvanometer and a field lens.

[0037] The pulse signals of the first electro-optical modulator 3-1 and the second electro-optical modulator 3-2 differ by a pulse period 1 / f, and can independently modulate the pulse sequence of the laser light source. The two optical paths after splitting can process the same graphics or different graphics. When processing the same graphics, when the processed graphics are relatively complex, such as when there are jumps or leaks, the two optical paths need to set different delays. The two lasers after splitting are controlled by their own independent light output signals, and there is no mutual interference in the graphics processing. When processing different graphics, the two lasers after splitting are independently controlled by their own electro-optical modulators, and there is no mutual interference during the processing.

[0038] As a specific application, it can be used in the field of solar cell laser processing technology to process the back side of the cell, such as grooving, scribing, and selective laser doping. Two cells are placed on corresponding processing stations, and the galvanometer scanning system is used to scan and process them according to the pattern of back side grooving, scribing, or selective laser doping. Since the optical paths can be controlled separately, different patterns can be processed, so different laser processes can also be performed on the two cells.

[0039] Embodiment 2:

[0040] The principle of this embodiment is the same as that of the first embodiment, except that: Figure 6 As shown, there are three splitting optical paths, namely: a third splitting optical path composed of a third electro-optical modulator 3-3 and a third polarization beam splitter 4-3, which is arranged after the second splitting optical path and before the beam cutoff 5, and outputs the third splitting optical path laser 6-3; the digital pulse delay generator 7 also sets the frequency for the third electro-optical modulator 3-3, and the third marking control card 8-3 provides a trigger signal for the third electro-optical modulator 3-3.

[0041] The reflection and transmission logic sequence of the laser pulse is as follows: Figure 7 As shown. Set the frequency of laser light source 1 to f , the frequencies of the first electro-optical modulator 3-1, the second electro-optical modulator 3-2 and the third electro-optical modulator 3-3 are f / 3, and at the same time, there is a 1 / between the frequencies of the first electro-optical modulator 3-1 and the second electro-optical modulator 3-2, and between the frequencies of the second electro-optical modulator 3-2 and the third electro-optical modulator 3-3. f time difference.

[0042] When the first marking control card 8-1 outputs a high level, the first electro-optical modulator 3-1 changes the polarization state of the laser, the laser beam is reflected on the first polarization beam splitter 4-1, and the first splitting light path laser 6-1 is output; when the first marking control card 8-1 outputs a low level, the laser beam is transmitted on the first polarization beam splitter 4-1, and this part of the transmitted light is not affected by the second electro-optical modulator 3-2 and the third electro-optical modulator 3-3, and is directly collected by the beam cutoff 5.

[0043] When the second marking control card 8-2 outputs a high level, the second electro-optical modulator 3-2 changes the polarization state of the laser, the laser beam is reflected on the second polarization beam splitter 4-2, and the second splitting light path laser 6-2 is output; when the second marking control card 8-2 outputs a low level, the laser beam is transmitted on the second polarization beam splitter 4-2, and this part of the transmitted light is not affected by the third electro-optical modulator 3-3 and is directly collected by the beam cutoff 5.

[0044] When the third marking control card 8-3 outputs a high level, the third electro-optical modulator 3-3 changes the laser polarization state, the laser beam is reflected on the third polarization beam splitter 4-3, and the third splitting optical path laser 6-3 is output; when the third marking control card 8-3 outputs a low level, the laser beam is transmitted on the third polarization beam splitter 4-3 and is directly collected by the beam cutoff 5.

[0045] The pulse signals of two adjacent electro-optic modulators differ by a pulse period 1 / f, and the laser pulse sequence can be modulated independently. When the processed graphics are more complex, such as jumps or leaks, the three lasers are controlled by their own independent light output signals, and there is no mutual interference in the graphics processing.

[0046] For more n-way splitting, n electro-optical modulators and n polarization beam splitters can be set according to Example 1 and Example 2. The frequency of each pulse signal is 1 / n of the laser pulse frequency. The signal start time differs from the initial time by 1, 2, ..., (n-1) laser pulse cycles, respectively, to achieve independent control of n-way time-sharing splitting.

[0047] Embodiment three:

[0048] The structure of this embodiment is the same as that of the first embodiment, and the principle is similar to that of the first embodiment, and the features are: Figure 8 As shown, when the first marking control card 8-1 outputs a high level and the second marking control card 8-2 outputs a low level, the first electro-optical modulator 3-1 changes the polarization state of the laser, thereby causing a reflection on the first polarization beam splitter 4-1. At this time, the laser 6-1 of the first light splitting path is output, while the laser 6-2 of the second light splitting path is not output. When the first marking control card 8-1 outputs a low level and the second marking control card 8-2 outputs a high level, the first electro-optical modulator 3-1 does not change the polarization state of the laser. After the laser passes through the first polarization beam splitter 4-1, it is modulated by the second electro-optical modulator 3-2 to change the polarization state, thereby causing a reflection on the second polarization beam splitter 4-2. At this time, the laser 6-2 of the second light splitting path is output, while the laser 6-1 of the first light splitting path is not output.

[0049] By adopting the timing design of this embodiment, the optical path can be quickly switched between the first split light path laser 6-1 and the second split light path laser 6-2, realizing time-sharing and light-sharing control. When the first split light path laser 6-1 is in working state, the processing workpiece corresponding to the second split light path laser 6-2 can be transmitted to the place; when the second split light path laser 6-2 is in working state, the processing workpiece corresponding to the first split light path laser 6-1 can be transmitted to the place, thereby saving the time of workpiece transmission and improving the processing efficiency of the equipment.

[0050] Embodiment 4:

[0051] The structure of this embodiment is the same as that of the third embodiment, and the principle is similar to that of the third embodiment, except that: Fig. 9 As shown, the digital pulse delay generator 7 sets the frequencies of the laser light source 1, the first electro-optic modulator 3-1 and the second electro-optic modulator 3-2 to be f. When the first marking control card 8-1 outputs a high level and the second marking control card 8-2 outputs a low level, the first electro-optical modulator 3-1 changes the polarization state of the laser, thereby causing a reflection on the first polarization beam splitter 4-1. At this time, the laser 6-1 of the first splitting light path is output, while the laser 6-2 of the second splitting light path is not output. When the first marking control card 8-1 outputs a low level and the second marking control card 8-2 outputs a high level, the first electro-optical modulator 3-1 does not change the polarization state of the laser. After the laser passes through the first polarization beam splitter 4-1, it is modulated by the second electro-optical modulator 3-2 to change the polarization state, thereby causing a reflection on the second polarization beam splitter 4-2. At this time, the laser 6-2 of the second splitting light path is output, while the laser 6-1 of the first splitting light path is not output.

[0052] By adopting the timing design of this embodiment, the optical path can be quickly switched between the first split optical path laser 6-1 and the second split optical path laser 6-2 without changing the laser pulse frequency, thereby realizing time-sharing and light-sharing control. When the first split optical path laser 6-1 is in working state, the processing workpiece corresponding to the second split optical path laser 6-2 can be transmitted to the position; when the second split optical path laser 6-2 is in working state, the processing workpiece corresponding to the first split optical path laser 6-1 can be transmitted to the position, thereby saving the time of workpiece transmission and improving the processing efficiency of the equipment.

[0053] It can be seen from the above four embodiments that various timing logic controls can be realized through the combined control of the digital pulse delay generator 7 and the marking control card, and the split light paths after splitting are independent of each other and do not interfere with each other.

[0054] The above embodiments are only used to illustrate the design ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design ideas disclosed by the present invention are within the protection scope of the present invention.

Claims

1. A laser processing system, characterized in that: It comprises an independently controllable laser time-division and light-splitting system; the independently controllable laser time-division and light-splitting system comprises a laser light source, at least two light-splitting optical paths and a digital pulse delay generator; wherein each light-splitting optical path comprises an electro-optic modulator and a polarization beam splitter, and the light-splitting optical paths are arranged in sequence; the laser light source emits a laser pulse of a certain frequency, which passes through the electro-optic modulator and the polarization beam splitter of the first to the last light-splitting optical paths in sequence, and the electro-optic modulator splits part of the laser pulse and outputs it from the polarization beam splitter; the digital pulse delay generator is used to trigger the laser pulse, set the frequency of the laser pulse, and the frequency and delay of the electro-optic modulator of each light-splitting optical path; The laser pulse output by each split optical path is used as a processing optical path for laser processing. Each processing optical path is equipped with a corresponding controller for controlling the processing path and the switch of the electro-optical modulator. According to the laser processing timing corresponding to each processing optical path, the digital pulse delay generator sets the frequency for the laser light source and the electro-optical modulator of each split optical path, and the controller sends a trigger signal to the electro-optical modulator of the corresponding processing optical path. The digital pulse delay generator is based on a frequency f Trigger the laser pulse and set the sum of the frequencies of the electro-optic modulators of each split optical path to be less than or equal to f , and a delay is provided between the signals of each split light path, so that the laser pulse is not repeatedly divided into the split light paths; The controller is used to provide a trigger signal for each electro-optic modulator, and the electro-optic modulator performs light splitting under the combined action of the trigger signal and the frequency control of the digital pulse delay generator; It also includes a beam cutoff, which is arranged at the rear end of the last split light path and is used for absorbing the laser pulses that are not split.

2. The laser processing system according to claim 1, characterized in that: A phase delay device is also arranged between the laser light source and the first split light path.

3. The laser processing system according to claim 1, characterized in that: The digital pulse delay generator sets the frequency of the laser source to f , set the frequency of the electro-optic modulator of each split optical path to f / n, n is the total number of split light paths, and the signal start time of the next split light path differs from that of the previous split light path by 1 laser pulse cycle 1 / f .

4. The laser processing system according to claim 3, characterized in that: The processing patterns corresponding to each processing light path are the same; the period at which each controller sends a trigger signal to the electro-optical modulator of the corresponding processing light path is also the same; when the corresponding processing light path is being processed, the trigger signal sent by the controller is a high level; when the corresponding processing light path is not being processed, the trigger signal sent by the controller is a low level.

5. The laser processing system according to claim 1, characterized in that: The digital pulse delay generator sets the frequencies of the laser light source and the electro-optic modulators of each split light path to be f ; Each processing light path corresponds to a processing station, and only one processing station is processed at a time; when the corresponding processing light path is being processed, the trigger signal issued by the controller is a high level; when the corresponding processing light path is not being processed, the trigger signal issued by the controller is a low level.

6. The laser processing system according to claim 1, characterized in that: Each processing light path corresponds to a processing station, and each processing station includes an electric processing platform to achieve two-dimensional or three-dimensional movement, driving the workpiece thereon to move according to a preset processing pattern to complete the processing.

7. The laser processing system according to claim 1, characterized in that: A galvanometer scanning system is also provided at the end of each processing light path to scan and process the light path according to the preset processing pattern of the workpiece.

8. A laser processing method implemented by the laser processing system according to claim 1, characterized in that: The laser light from the same laser light source is distributed to several split light paths. The frequency of the laser light source and the electro-optical modulator of each split light path is set by a digital pulse delay generator. At the same time, the controller sends a trigger signal to the electro-optical modulator of the corresponding processing light path to achieve independent control of each split light path. The specific settings of the digital pulse delay generator and the controller are determined according to the laser processing timing corresponding to each processing light path.

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