CN118232156A - Pulse cluster composite pulse laser device and output method - Google Patents

Abstract

The present invention provides a pulse cluster composite pulse laser device and output method, which relates to the field of laser technology. The device includes a first cavity mirror, a λ/4 wave plate, an RTP Q switch, a polarizer, a first pump module, a first laser crystal, a polarization beam splitter, an output mirror, a second pump module, a second laser crystal, an acousto-optic Q switch, a second cavity mirror, a signal generator, a delay device, a laser detection device, and an information processing device. The present invention realizes the output of long-wave ms-level pulse laser, ns-level pulse laser or ms-ns pulse cluster and laser pulse clusters in different combinations thereof by cooperating with an acousto-optic Q switch and an electro-optic Q switch, and switches the laser peak power according to actual needs through a signal processing device, thereby realizing real-time cleaning and avoiding damage caused by excessive peak power. By adjusting the delay device, adjusting the ms-ns interval composite pulse cluster laser duty cycle and acting in sequence, rapid cleaning of the target material is realized.

Description

A pulse cluster composite pulse laser device and output method

Technical Field

The present invention generally relates to the field of laser technology, and in particular to a pulse cluster composite pulse laser device and method.

Background technique

Laser heat treatment of metal materials has the characteristics of green cleaning, high precision and low cost, and is widely used in many fields such as industrial processing, aerospace, optical information storage and scientific research. The use of single pulse laser or continuous laser to heat treat metal materials has the problem of low laser energy absorption rate and unsatisfactory processing effect. In order to improve the cleaning effect of the target object, by combining laser beams with different pulse sequences, their respective characteristics and interaction mechanisms can be utilized to achieve a more powerful laser damage capability.

Pulse sequence control is to achieve complex laser cleaning effects by precisely controlling the sequence and time interval of laser pulses. Changes in the pulse sequence can control the interaction between the laser and the target material, thereby achieving more accurate and diverse cleaning effects. However, existing lasers can only achieve single continuous, pulse compounding, or ms and ns pulse compounding. CN116544763A discloses a composite pulse laser and its working method, which only discloses a laser that realizes composite pulse laser output, but does not disclose the specific implementation method of the composite pulse cluster and the setting of the pulse sequence in the application scenario for different target materials, that is, the pulse laser disclosed in the prior art cannot achieve rapid switching of laser pulses and precise short time interval control, which is still a challenge for high-speed or real-time applications. To achieve "high-speed superposition" of the physical field, the sub-pulse time domain interval of the pulse cluster laser is required to be extremely short, which needs to reach at least the order of ns. To achieve real-time application, it is necessary to optimize the pulse peak power in real time according to the material. Therefore, the innovation of short-time domain ns interval ms-ns composite pulse cluster laser is the key to the development of laser cleaning.

Summary of the invention

In order to realize fast switching of laser pulses of a composite pulse laser device and accurate short time interval control, the present invention provides a pulse cluster composite pulse laser device and method.

A pulse cluster composite pulse laser device provided by the present invention is described below with reference to FIGS. 1 to 8 .

Fig. 1 is a schematic diagram of a pulse cluster composite pulse laser device according to an embodiment of the present invention. As shown in Fig. 1, a pulse cluster composite pulse laser device includes: a first cavity mirror 1, a λ/4 wave plate 2, an RTP Q switch 3, a polarizer 4, a first pump module 5, a first laser crystal 6, a polarization beam splitter prism 7, an output mirror 8, a second pump module 9, a second laser crystal 10, an acousto-optic Q switch 11, a second cavity mirror 13, a signal generator 12, a delay device 14, a laser detection device 15, and an information processing device 16, wherein:

The first cavity mirror 1 and the output mirror 8 form a ms pulse laser linear resonant cavity, and the output mirror 8, the polarization beam splitter prism 7, and the second cavity mirror 13 form an L-shaped ns pulse laser resonant cavity;

The λ/4 wave plate 2, the RTP Q switch 3, the polarizer 4, the first laser crystal 6, and the polarization beam splitter prism 7 are sequentially arranged between the first cavity mirror 1 and the output mirror 8;

The acousto-optic Q switch 11 and the second laser crystal 10 are sequentially arranged between the second cavity mirror 13 and the polarization beam splitter prism 7;

The first laser crystal 6 and the second laser crystal 10 are anisotropic laser crystals, and the first laser crystal 6 and the second laser crystal 10 are Nd:YVO ₄ crystals, Nd:YAP crystals or Nd:YLF crystals;

The first pump module 5 is located on the side of the first laser crystal 6, and the second pump module 9 is located on the side of the second laser crystal 10;

The signal generator 12 is electrically connected to the acousto-optic Q switch 11, and the signal generator 12 adjusts the amplitude of the RF signal of the acousto-optic Q switch 11 by controlling the feedback voltage;

The laser detection device 15 is located above the second cavity mirror 13;

The information processing device 16 is electrically connected to the signal generator 12, the delay device 14 and the laser detection device 15;

The delay device 14 is connected to the first pump module 5 and the second pump module 9;

The incident surface of the polarization beam splitter prism 7 faces the first cavity mirror 1, the horizontal polarization output surface faces the output mirror 8, and the vertical polarization output surface faces the opposite direction of the second cavity mirror 13;

The polarization direction of the polarizer 4 is horizontal;

The fast axis of the λ/4 wave plate 2 also forms an angle of 45° with the horizontal direction;

Specifically, the output wavelength of the first pump module 5 and the second pump module 9 is 880 nm, and the thermal boost pumping is directly pumped from the ground state energy level to the laser upper energy level;

Specifically, the output mirror 8, the first cavity mirror 1, and the second cavity mirror 13 are plane mirrors;

Specifically, the surface of the output mirror 8 facing the resonant cavity is coated with a 1064nm anti-reflection film, and the surface facing away from the resonant cavity is coated with a 1064nm high-transmittance film with a transmittance of 20%; the first cavity mirror 1 is coated with 880nm and 1064nm total reflection films; the second cavity mirror 13 is coated with an 880nm total reflection film and a 1064nm high-transmittance film with a transmittance of 10%;

Since the components of the parts to be cleaned at different depths on the surface of the material to be cleaned are different during the laser cleaning process, if only a single mode or a fixed sequence of pulse clusters is used for laser cleaning, the cleaning effect or efficiency will be poor. Therefore, the present invention monitors the cleaning state of the surface of the material to be cleaned in real time and dynamically adjusts the output pulse cluster sequence to improve the cleaning effect and cleaning efficiency.

Specifically, as shown in Figure 6, there is a schematic diagram of a pulse cluster composite pulse laser device with a dynamic detection function, the pulse cluster composite pulse laser device also includes a material detection device 17, the material detection device 17 is arranged at the material to be cleaned 18, and is used to feedback the cleaning status of the material to be cleaned 18; the material detection device 17 is electrically connected to the information processing device 16, and is used to feedback the real-time cleaning status to the information processing device 16. The information processing device 16 sends a control signal to the signal generator 12 and the delay device 14 according to the real-time cleaning status, so as to change the pulse cluster sequence output by the pulse cluster composite pulse laser device, and realize the pulse cluster output that matches the real-time cleaning status of the surface of the material to be cleaned 18.

The specific implementation process of a pulse cluster composite pulse laser device of the present invention is as follows:

As shown in FIG1 , a schematic diagram of a pulse cluster composite pulse laser device is shown. The pump light emitted by the first pump module 5 and the second pump module 9 pumps the first laser crystal 6 and the second laser crystal 10. The first laser crystal 6 and the second laser crystal 10 absorb the pump light emitted by the first pump module 5 and the second pump module 9 to form a population inversion, and stimulated radiation occurs to generate a 1064nm laser. The horizontal ms pulse laser passes through the polarizer 4 to form a horizontally polarized 1064nm laser. After electro-optical Q modulation, the horizontally polarized 1064nm ms pulse laser is finally output through the output mirror 8. The vertical ns laser passes through the polarization beam splitter 7 to form a vertically polarized 1064nm laser. The signal generator 12 connected to the acousto-optic Q switch 11 is controlled to make the acousto-optic Q switch 11 in a single step mode and a multi-step Q-switching mode, that is, a traditional acousto-optic Q-switching mode and a multi-step Q-switching mode, so as to realize ns laser and short-time domain ns interval sub-pulses. In Figures 2 to 5, a dot represents vertical polarization, a double-direction arrow represents horizontal polarization, and a single-direction arrow represents 45° polarization.

As shown in Figure 2, it is a schematic diagram of the laser polarization state conversion state during forward propagation when the RTP Q switch is not loaded with voltage. When the RTP Q switch 3 is not loaded with voltage, the 1064nm laser propagating horizontally to the left passes through the polarizer 4 and becomes a horizontally polarized 1064nm laser (the horizontally polarized 1064nm laser is represented by a double-headed arrow in Figure 2, and the horizontal polarization direction is the direction parallel to the paper surface in Figure 2), and is reflected by the first cavity mirror 1 after passing through the RTP Q switch 3 and the λ/4 wave plate 2.

As shown in Figure 3, it is a schematic diagram of the laser polarization state conversion state during reverse propagation when the RTP Q switch is not loaded with voltage. The 1064nm laser reflected by the first cavity mirror 1 (horizontally propagating to the right) passes through the λ/4 wave plate 2, and the polarization state of the 1064nm laser is converted to vertical polarization (the midpoint in Figure 2 represents the vertically polarized 1064nm laser, and the vertical polarization direction is the direction perpendicular to the paper in Figure 2). After passing through the RTP Q switch 3, the polarization state remains unchanged and cannot pass through the polarizer 4. At this time, the ms laser is in a "closed" state.

As shown in Figure 4, it is a schematic diagram of the laser polarization state conversion state during forward propagation when the RTP Q switch is loaded with a λ/4 voltage. When the RTP Q switch 3 is loaded with a λ/4 voltage, the horizontally polarized 1064nm laser passes through the RTP Q switch 3 and the λ/4 wave plate 2 in sequence, becomes vertically polarized, and is then reflected by the first cavity mirror 1.

As shown in Figure 5, it is a schematic diagram of the laser polarization state conversion state during reverse propagation when the RTP Q switch is loaded with a λ/4 voltage. After the vertically polarized 1064nm laser reflected by the first cavity mirror 1 passes through the λ/4 wave plate 2 and the RTP Q switch 3, the polarization state of the 1064nm laser changes to horizontal polarization, passes through the polarizer 4, the Nd:YVO ₄ crystal 6, the polarization beam splitter prism 7, and then is emitted out of the cavity through the output mirror 8. At this time, the ms laser is in the "open door" state.

As shown in FIG7 , it is a schematic diagram of the laser output state in the first composite form. FIG7 (a) shows that the acousto-optic Q switch 11 is always at a high voltage. When the electro-optic Q switch 11 is loaded with a λ/4 voltage, only ms pulse laser is output. In order to demonstrate the coexistence of ns and ms, the dotted line represents the time continuation. FIG7 (b) shows that the acousto-optic Q switch 11 is in a single-step signal. When the electro-optic Q switch 3 is not loaded with a voltage, only ns pulse laser is output. FIG7 (c) shows that the acousto-optic Q switch 11 is in a multi-step signal. When the electro-optic Q switch 3 is not loaded with a voltage, only ns pulse cluster laser is output. By adjusting the acousto-optic Q switch 11 to present different step losses, a single pulse can be output with different repetition rates. FIG7 (c) shows the pulse cluster effect presented when there are 5 uniform steps, and the required pulse cluster signal can also be presented as required. FIG7 (d) shows that the acousto-optic Q switch 11 is a multi-step signal. When the electro-optic Q switch 3 is loaded with a λ/4 voltage, ms-ns interval composite pulse cluster laser is output. The first pump module 5 and the second pump module 9 are controlled simultaneously by the delay device 14 to realize different pump delays, and finally realize the ms-ns interval composite pulse cluster laser duty cycle and sequential action.

As shown in FIG8 , it is a schematic diagram of the second composite form of laser output state. The delay device 14 can realize the minimum delay control of 300ps. According to actual needs, a specific delay can be set to realize a ms and ns interval pulse cluster composite pulse laser device with adjustable duty cycle and action order. FIG8(a) is a schematic diagram of a pulse cluster combination of ms-ns pulses obtained by first acting with the delay device 14, and then using a short ns pulse cluster; FIG8(b) is a pulse cluster combination of ns-ms-ns pulses obtained by first acting with the delay device 14, and then with the ms long pulse laser, and then using a short ns pulse cluster, to obtain a pulse cluster combination of ns-ms-ns pulses, and to obtain the effect of alternating action of ns pulse clusters and ms pulses; FIG8(c) is a continuous action of ms and ns pulse clusters, and "..." is used to represent the continuous action of ns pulse clusters; FIG8(d) is a combination of ms and ns pulse clusters set arbitrarily according to needs.

The power and pulse width are collected by the laser detection device 15, and the information processing device 16 compares the output peak power with the damage threshold of the material. When the peak power is too high, the feedback voltage of the signal generator 12 is increased, thereby reducing the RF signal amplitude of the acousto-optic Q switch 11 and reducing the output peak power; when the peak power is too low, the feedback voltage of the signal generator 12 is reduced until the peak power output reaches the set value.

According to another aspect of the present invention, there is also provided an output method using any of the above-mentioned pulse cluster composite pulse laser devices, the output method comprising:

Select pulse cluster sequence parameters according to the material to be cleaned 18, and determine the pulse cluster setting value, wherein the setting value includes the pulse cluster sequence parameters and the output laser peak power;

The first pump module 5 and the second pump module 9 emit pump light to side-pump the first laser crystal 6 and the second laser crystal 10;

The first laser crystal 6 and the second laser crystal 10 absorb the pump light to form a particle beam inversion, and stimulated radiation occurs to generate 1064nm laser;

The 1064nm laser light propagating in the vertical direction only retains the vertical polarization after passing through the polarization beam splitter prism 7, and the 1064nm laser light propagating in the horizontal direction only retains the horizontal polarization after passing through the polarization beam splitter prism 7, and both are emitted through the output mirror 8;

When there is no need to emit ms laser, the RTP Q switch 3 is controlled to be unloaded with voltage, and the 1064nm laser propagating in the horizontal direction becomes a horizontally polarized 1064nm laser after passing through the polarizer 4. After passing through the RTP Q switch 3 and the λ/4 wave plate 2, it is reflected by the first cavity mirror 1, and then after passing through the λ/4 wave plate 2, the polarization state of the 1064nm laser is changed from horizontal polarization to vertical polarization. After passing through the RTP Q switch 3, the polarization state is still vertically polarized and cannot pass through the polarizer 4;

When it is necessary to emit ms laser, the RTP Q switch 3 is controlled to load a λ/4 voltage, and the 1064nm laser propagating in the horizontal direction becomes a horizontally polarized 1064nm laser after passing through the polarizer 4. After passing through the RTP Q switch 3 and the λ/4 wave plate 2, the polarization state of the 1064nm laser is changed from horizontal polarization to vertical polarization. The vertically polarized 1064nm laser is reflected by the first cavity mirror 1, and then passes through the λ/4 wave plate 2 and the RTP Q switch 3. The polarization state of the 1064nm laser is changed from vertical polarization to horizontal polarization. After passing through the polarizer 4, the first laser crystal 6, and the polarization beam splitter prism 7, the 1064nm laser is emitted from the output mirror 8;

When ns laser emission is required, the signal generator 12 externally connected to the acousto-optic Q switch 11 is controlled to put the acousto-optic Q switch 11 in a single-step mode, i.e., a conventional acousto-optic Q-switching mode, to achieve ns laser output;

When it is necessary to obtain a pulse cluster with a ns interval, the signal generator 12 externally connected to the acousto-optic Q switch 11 is in a multi-step Q-switching state to achieve a short-time domain ns-interval sub-pulse output;

According to the set value, the ms-ns interval composite pulse cluster laser duty cycle is adjusted by controlling the delay device 14 and acting in sequence to achieve pulse cluster ms-ns time domain frequency composite point matching;

The output power and pulse width of the ns pulse cluster measured by the laser detection device 15 are transmitted to the information processing device 16 to calculate the peak power of the ns pulse cluster, and the information processing device 16 makes a determination according to the set value;

When the information processing device 16 determines that the peak power is too high, the information processing device 16 transmits a signal to the signal generator 12, and the signal generator 12 increases the feedback voltage, thereby causing the amplitude of the radio frequency signal driving the acousto-optic Q switch 11 to decrease, thereby reducing the peak power;

When the information processing device 16 determines that the peak power is too low, the information processing device 16 transmits a signal to the signal generator 12, and the signal generator 12 reduces the feedback voltage, thereby causing the amplitude of the radio frequency signal driving the acousto-optic Q switch 11 to increase, thereby increasing the peak power;

When the information processing device 16 determines that the output laser peak power reaches the set value, it implements peak power matching according to actual needs.

Specifically, it also includes:

The delay device 14 can achieve a minimum delay control of 300ps. The pulse cluster shape is determined according to the material to be cleaned 18, and the delay device 14 is adjusted to achieve the output of ms and ns interval pulse cluster composite pulses with adjustable duty cycle and action order;

The delay device 14 is adjusted to realize the first action of the ms long pulse laser, and after the ms long pulse output is turned off, the short ns pulse cluster is used to obtain the pulse cluster combination of ms-ns pulses;

The delay device 14 is adjusted to realize the first action of ns short pulse laser, the action of ms long pulse laser after the ns short pulse output is turned off, and the action of short ns pulse cluster is used after the ms long pulse output is turned off to obtain the pulse cluster combination of ns-ms-ns pulses;

The delay device 14 is adjusted to realize the first action of the ns short pulse laser, and while maintaining the output of the ns short pulse laser, the ms long pulse laser is output to obtain the continuous action of the ms and ns pulse clusters;

The delay device 14 is adjusted to realize the simultaneous output of the ms long pulse laser and the ns short pulse laser, and then the ms long pulse laser or the ns short pulse laser is turned off to realize the single output of the ms long pulse laser and the ns short pulse laser.

Specifically, as shown in FIG6 , which is a schematic diagram of a pulse cluster composite pulse laser device with a dynamic detection function, the output method further includes:

The material detection device 17 disposed at the material to be cleaned 18 monitors the cleaning status of the material to be cleaned 18 in real time;

The material detection device 17 feeds back the real-time cleaning status to the information processing device 16;

The information processing device 16 sends a control signal to the signal generator 12 and the delay device 14 according to the real-time cleaning status to change the set value;

A pulse cluster output is achieved that matches the real-time cleaning status of the surface of the material 18 to be cleaned.

Specifically, it also includes:

The information processing device 16 is provided with an image recognition processing system, and the image recognition of the real-time state of the surface of the material to be cleaned 18 is completed according to the image recognition processing system;

According to the image recognition result, the morphological parameters of the area to be cleaned on the surface of the material to be cleaned 18 are determined;

A matching pulse cluster setting value is determined according to the morphology parameter.

The pulse cluster composite pulse laser device proposed in the present invention cleans the target material by long-wave ms-level pulse laser, ns-level pulse laser or ms-ns pulse cluster and different combinations thereof. 880nm thermal boost pumping is used to reduce the thermal effect of the crystal and improve the light-to-light conversion efficiency. The horizontal polarization of the 1064nm ms laser is retained by a polarization beam splitter prism, and the horizontally polarized 1064nm ms laser is turned on and off under the joint action of a polarizer, an RTP Q switch and a λ/4 wave plate. When the RTP Q switch is not loaded with voltage, the vertically polarized 1064nm laser cannot pass through the polarizer, that is, it presents a "closed" state. When the RTP Q switch is loaded with a λ/4 voltage, the 1064nm laser can oscillate in the resonant cavity, realizing the "open" state. The generation of the ns laser is controlled by a signal generator and an acousto-optic Q switch. When the signal generator is always loaded with a high voltage, it presents a "closed" state. When the signal generator presents a single-step voltage, ns laser output is achieved; when the signal generator presents multiple steps, short-time domain ns-interval sub-pulses are achieved, and the "open door" state is achieved. A shorter ns pulse cluster increases the pulse frequency of the ns-timed pulse cluster, generating a physical mechanism dominated by shock waves and stress. Through the signal processing device, the laser peak power is switched according to actual needs, so as to achieve real-time cleaning and avoid damage caused by excessive peak power. By adjusting the delay device, adjusting the laser duty cycle of the ms-ns-interval composite pulse cluster and acting in sequence, the target material can be quickly cleaned. In addition, since the components of the parts to be cleaned at different depths on the surface of the material to be cleaned are different during the laser cleaning process, if only a single mode or a fixed sequence of pulse clusters is used for laser cleaning, the cleaning effect will be poor or the efficiency will be low. Therefore, the present invention monitors the cleaning state of the surface of the material to be cleaned in real time, dynamically adjusts the output pulse cluster sequence, and provides cleaning effect and cleaning efficiency.

It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features, advantages and aspects of the embodiments of the present invention will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

FIG1 is a schematic diagram of a pulse cluster composite pulse laser device.

FIG2 is a schematic diagram of the laser polarization state conversion state during forward propagation when the RTP Q switch is not loaded with voltage.

FIG3 is a schematic diagram of the laser polarization state conversion state during reverse propagation when the RTP Q switch is not loaded with voltage.

FIG4 is a schematic diagram of the laser polarization state conversion state during forward propagation when the RTP Q switch is loaded with a λ/4 voltage.

FIG5 is a schematic diagram of the laser polarization state conversion state during reverse propagation when the RTP Q switch is loaded with a λ/4 voltage.

FIG. 6 is a schematic diagram of a pulse cluster composite pulse laser device with a dynamic detection function.

FIG. 7 is a schematic diagram of the laser output state of the first composite form.

FIG8 is a schematic diagram of the laser output state in the second composite form.

In FIG1 , the structural components indicated by the reference numerals are:

1 The first cavity mirror, 2 λ/4 wave plate, 3 RTP Q switch, 4 polarizer, 5 The first pump module, 6 The first laser crystal, 7 Polarization beam splitter, 8 Output mirror, 9 The second pump module, 10 The second laser crystal, 11 Acousto-optic Q switch, 12 Signal generator, 13 The second cavity mirror, 14 Delay device, 15 Laser detection device, 16 Information processing device, 17 Material detection device, 18 Material to be cleaned.

Detailed ways

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In addition, the term "and/or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.

A pulse cluster composite pulse laser device provided by an embodiment of the present invention is described below with reference to FIGS. 1 to 8 .

Fig. 1 is a schematic diagram of a pulse cluster composite pulse laser device according to an embodiment of the present invention. As shown in Fig. 1, a pulse cluster composite pulse laser device includes: a first cavity mirror 1, a λ/4 wave plate 2, an RTP Q switch 3, a polarizer 4, a first pump module 5, a first laser crystal 6, a polarization beam splitter prism 7, an output mirror 8, a second pump module 9, a second laser crystal 10, an acousto-optic Q switch 11, a second cavity mirror 13, a signal generator 12, a delay device 14, a laser detection device 15, and an information processing device 16, wherein:

The first cavity mirror 1 and the output mirror 8 form a ms pulse laser linear resonant cavity, and the output mirror 8, the polarization beam splitter prism 7, and the second cavity mirror 13 form an L-shaped ns pulse laser resonant cavity;

The λ/4 wave plate 2, the RTP Q switch 3, the polarizer 4, the first laser crystal 6, and the polarization beam splitter prism 7 are sequentially arranged between the first cavity mirror 1 and the output mirror 8;

The acousto-optic Q switch 11 and the second laser crystal 10 are sequentially arranged between the second cavity mirror 13 and the polarization beam splitter prism 7;

The first laser crystal 6 and the second laser crystal 10 are anisotropic laser crystals. Preferably, the first laser crystal 6 and the second laser crystal 10 are Nd:YVO ₄ crystals, Nd:YAP crystals or Nd:YLF crystals;

The first pump module 5 is located on the side of the first laser crystal 6, and the second pump module 9 is located on the side of the second laser crystal 10;

The signal generator 12 is electrically connected to the acousto-optic Q switch 11, and the signal generator 12 adjusts the amplitude of the RF signal of the acousto-optic Q switch 11 by controlling the feedback voltage;

The laser detection device 15 is located above the second cavity mirror 13;

The information processing device 16 is electrically connected to the signal generator 12, the delay device 14 and the laser detection device 15;

The delay device 14 is connected to the first pump module 5 and the second pump module 9;

The incident surface of the polarization beam splitter prism 7 faces the first cavity mirror 1, the horizontal polarization output surface faces the output mirror 8, and the vertical polarization output surface faces the opposite direction of the second cavity mirror 13;

The polarization direction of the polarizer 4 is horizontal;

The fast axis of the λ/4 wave plate 2 also forms an angle of 45° with the horizontal direction;

Preferably, the output wavelength of the first pump module 5 and the second pump module 9 is 880 nm, and the thermal boost pumping is directly pumped from the ground state energy level to the laser upper energy level;

Preferably, the output mirror 8, the first cavity mirror 1, and the second cavity mirror 13 are plane mirrors;

Preferably, the surface of the output mirror 8 facing the resonant cavity is coated with a 1064nm anti-reflection film, and the surface facing away from the resonant cavity is coated with a 1064nm high-transmittance film with a transmittance of 20%; the first cavity mirror 1 is coated with 880nm and 1064nm total reflection films; the second cavity mirror 13 is coated with an 880nm total reflection film and a 1064nm high-transmittance film with a transmittance of 10%;

Preferably, as shown in Figure 6, there is a schematic diagram of a pulse cluster composite pulse laser device with a dynamic detection function, wherein the pulse cluster composite pulse laser device also includes a material detection device 17, and the material detection device 17 is arranged at the material to be cleaned 18, and is used to provide feedback on the cleaning status of the material to be cleaned 18; the material detection device 17 is electrically connected to the information processing device 16, and is used to provide feedback on the real-time cleaning status to the information processing device 16, and the information processing device 16 sends a control signal to the signal generator 12 and the delay device 14 according to the real-time cleaning status, so as to change the pulse cluster sequence output by the pulse cluster composite pulse laser device, and realize a pulse cluster output that matches the real-time cleaning status of the surface of the material to be cleaned 18.

The specific implementation process of a pulse cluster composite pulse laser device of the present invention is as follows:

As shown in FIG1 , a schematic diagram of a pulse cluster composite pulse laser device is shown. The pump light emitted by the first pump module 5 and the second pump module 9 pumps the first laser crystal 6 and the second laser crystal 10. The first laser crystal 6 and the second laser crystal 10 absorb the pump light emitted by the first pump module 5 and the second pump module 9 to form a population inversion, and stimulated radiation occurs to generate a 1064nm laser. The horizontal ms pulse laser passes through the polarizer 4 to form a horizontally polarized 1064nm laser. After electro-optical Q modulation, the horizontally polarized 1064nm ms pulse laser is finally output through the output mirror 8. The vertical ns laser passes through the polarization beam splitter 7 to form a vertically polarized 1064nm laser. The signal generator 12 connected to the acousto-optic Q switch 11 is controlled to make the acousto-optic Q switch 11 in a single step mode and a multi-step Q-switching mode, that is, a traditional acousto-optic Q-switching mode and a multi-step Q-switching mode, so as to realize ns laser and short-time domain ns interval sub-pulses. In Figures 2 to 5, a dot represents vertical polarization, a double-direction arrow represents horizontal polarization, and a single-direction arrow represents 45° polarization.

As shown in Figure 2, it is a schematic diagram of the laser polarization state conversion state during forward propagation when the RTP Q switch is not loaded with voltage. When the RTP Q switch 3 is not loaded with voltage, the 1064nm laser propagating in the horizontal direction becomes a horizontally polarized 1064nm laser after passing through the polarizer 4 (the horizontally polarized 1064nm laser is represented by a double-headed arrow in Figure 2, and the horizontal polarization direction is the direction parallel to the paper surface in Figure 2), and is reflected by the first cavity mirror 1 after passing through the RTP Q switch 3 and the λ/4 wave plate 2.

As shown in Figure 3, it is a schematic diagram of the laser polarization state conversion state during reverse propagation when the RTP Q switch is not loaded with voltage. The 1064nm laser reflected by the first cavity mirror 1 (horizontally propagating to the right) passes through the λ/4 wave plate 2, and the polarization state of the 1064nm laser is converted to vertical polarization (the midpoint in Figure 2 represents the vertically polarized 1064nm laser, and the vertical polarization direction is the direction perpendicular to the paper in Figure 2). After passing through the RTP Q switch 3, the polarization state remains unchanged and cannot pass through the polarizer 4. At this time, the ms laser is in a "closed" state.

As shown in Figure 4, it is a schematic diagram of the laser polarization state conversion state during forward propagation when the RTP Q switch is loaded with a λ/4 voltage. When the RTP Q switch 3 is loaded with a λ/4 voltage, the horizontally polarized 1064nm laser passes through the RTP Q switch 3 and the λ/4 wave plate 2 in sequence, becomes vertically polarized, and is then reflected by the first cavity mirror 1.

As shown in Figure 5, it is a schematic diagram of the laser polarization state conversion state during reverse propagation when the RTP Q switch is loaded with a λ/4 voltage. After the vertically polarized 1064nm laser reflected by the first cavity mirror 1 passes through the λ/4 wave plate 2 and the RTP Q switch 3, the polarization state of the 1064nm laser changes to horizontal polarization, passes through the polarizer 4, the Nd:YVO ₄ crystal 6, the polarization beam splitter prism 7, and then is emitted out of the cavity through the output mirror 8. At this time, the ms laser is in the "open door" state.

As shown in FIG7 , it is a schematic diagram of the laser output state in the first composite form. FIG7 (a) shows that the acousto-optic Q switch 11 is always at a high voltage. When the electro-optic Q switch 11 is loaded with a λ/4 voltage, only ms pulse laser is output. In order to demonstrate the coexistence of ns and ms, the dotted line represents the time continuation. FIG7 (b) shows that the acousto-optic Q switch 11 is in a single-step signal. When the electro-optic Q switch 3 is not loaded with a voltage, only ns pulse laser is output. FIG7 (c) shows that the acousto-optic Q switch 11 is in a multi-step signal. When the electro-optic Q switch 3 is not loaded with a voltage, only ns pulse cluster laser is output. By adjusting the acousto-optic Q switch 11 to present different step losses, a single pulse can be output with different repetition rates. FIG7 (c) shows the pulse cluster effect presented when there are 5 uniform steps, and the required pulse cluster signal can also be presented as required. FIG7 (d) shows that the acousto-optic Q switch 11 is a multi-step signal. When the electro-optic Q switch 3 is loaded with a λ/4 voltage, ms-ns interval composite pulse cluster laser is output. The first pump module 5 and the second pump module 9 are controlled simultaneously by the delay device 14 to realize different pump delays, and finally realize the ms-ns interval composite pulse cluster laser duty cycle and sequential action.

As shown in FIG8 , it is a schematic diagram of the second composite form of laser output state. The delay device 14 can realize the minimum delay control of 300ps. According to actual needs, a specific delay can be set to realize a ms and ns interval pulse cluster composite pulse laser device with adjustable duty cycle and action order. FIG8(a) is a schematic diagram of a pulse cluster combination of ms-ns pulses obtained by first acting with the delay device 14, and then using a short ns pulse cluster; FIG8(b) is a pulse cluster combination of ns-ms-ns pulses obtained by first acting with the delay device 14, and then acting with the ms long pulse laser, and then using a short ns pulse cluster, and obtaining a pulse cluster combination of ns-ms-ns pulses, and obtaining the effect of alternating action of ns pulse clusters and ms pulses; FIG8(c) is a continuous action of ms and ns pulse clusters, and "..." is used to represent the continuous action of ns pulse clusters; FIG8(d) is a combination of ms and ns pulse clusters set arbitrarily according to needs.

The power and pulse width are collected by the laser detection device 15, and the information processing device 16 compares the output peak power with the damage threshold of the material. When the peak power is too high, the feedback voltage of the signal generator 12 is increased, thereby reducing the RF signal amplitude of the acousto-optic Q switch 11 and reducing the output peak power; when the peak power is too low, the feedback voltage of the signal generator 12 is reduced until the peak power output reaches the set value.

According to another aspect of the present invention, there is also provided an output method using any of the above-mentioned pulse cluster composite pulse laser devices, the output method comprising:

Select pulse cluster sequence parameters according to the material to be cleaned 18, and determine the pulse cluster setting value, wherein the setting value includes the pulse cluster sequence parameters and the output laser peak power;

The first pump module 5 and the second pump module 9 emit pump light to side-pump the first laser crystal 6 and the second laser crystal 10;

The first laser crystal 6 and the second laser crystal 10 absorb the pump light to form a particle beam inversion, and stimulated radiation occurs to generate 1064nm laser;

The 1064nm laser light propagating in the vertical direction only retains the vertical polarization after passing through the polarization beam splitter prism 7, and the 1064nm laser light propagating in the horizontal direction only retains the horizontal polarization after passing through the polarization beam splitter prism 7, and both are emitted through the output mirror 8;

When there is no need to emit ms laser, the RTP Q switch 3 is controlled to be unloaded with voltage, and the 1064nm laser propagating in the horizontal direction becomes a horizontally polarized 1064nm laser after passing through the polarizer 4. After passing through the RTP Q switch 3 and the λ/4 wave plate 2, it is reflected by the first cavity mirror 1, and then after passing through the λ/4 wave plate 2, the polarization state of the 1064nm laser is changed from horizontal polarization to vertical polarization. After passing through the RTP Q switch 3, the polarization state is still vertically polarized and cannot pass through the polarizer 4;

When it is necessary to emit ms laser, the RTP Q switch 3 is controlled to load a λ/4 voltage, and the 1064nm laser propagating in the horizontal direction becomes a horizontally polarized 1064nm laser after passing through the polarizer 4. After passing through the RTP Q switch 3 and the λ/4 wave plate 2, the polarization state of the 1064nm laser is changed from horizontal polarization to vertical polarization. The vertically polarized 1064nm laser is reflected by the first cavity mirror 1, and then passes through the λ/4 wave plate 2 and the RTP Q switch 3. The polarization state of the 1064nm laser is changed from vertical polarization to horizontal polarization. After passing through the polarizer 4, the first laser crystal 6, and the polarization beam splitter prism 7, the 1064nm laser is emitted from the output mirror 8;

When ns laser emission is required, the signal generator 12 externally connected to the acousto-optic Q switch 11 is controlled to put the acousto-optic Q switch 11 in a single-step mode, i.e., a conventional acousto-optic Q-switching mode, to achieve ns laser output;

When it is necessary to obtain a pulse cluster with a ns interval, the signal generator 12 externally connected to the acousto-optic Q switch 11 is in a multi-step Q-switching state to achieve a short-time domain ns-interval sub-pulse output;

According to the set value, the ms-ns interval composite pulse cluster laser duty cycle is adjusted by controlling the delay device 14 and acting in sequence to achieve the pulse cluster ms-ns time domain frequency composite point matching;

The output power and pulse width of the ns pulse cluster measured by the laser detection device 15 are transmitted to the information processing device 16 to calculate the peak power of the ns pulse cluster, and the information processing device 16 makes a determination according to the set value;

When the information processing device 16 determines that the peak power is too high, the information processing device 16 transmits a signal to the signal generator 12, and the signal generator 12 increases the feedback voltage, thereby causing the amplitude of the radio frequency signal driving the acousto-optic Q switch 11 to decrease, thereby reducing the peak power;

When the information processing device 16 determines that the peak power is too low, the information processing device 16 transmits a signal to the signal generator 12, and the signal generator 12 reduces the feedback voltage, thereby causing the RF amplitude driving the acousto-optic Q switch 11 to increase, thereby increasing the peak power;

When the information processing device 16 determines that the output laser peak power reaches the set value, it implements peak power matching according to actual needs.

In one embodiment, it includes:

The delay device 14 can achieve a minimum delay control of 300ps. The pulse cluster shape is determined according to the material to be cleaned 18, and the delay device 14 is adjusted to achieve the output of ms and ns interval pulse cluster composite pulses with adjustable duty cycle and action order;

The delay device 14 is adjusted to realize the first action of the ms long pulse laser, and after the ms long pulse output is turned off, the short ns pulse cluster is used to obtain a pulse cluster combination of ms-ns pulses;

The delay device 14 is adjusted to realize the first action of ns short pulse laser, the action of ms long pulse laser after the ns short pulse output is turned off, and the action of short ns pulse cluster is used after the ms long pulse output is turned off to obtain the pulse cluster combination of ns-ms-ns pulses;

The delay device 14 is adjusted to realize the first action of the ns short pulse laser, and while maintaining the output of the ns short pulse laser, the ms long pulse laser is output to obtain the continuous action of the ms and ns pulse clusters;

The delay device 14 is adjusted to realize the simultaneous output of the ms long pulse laser and the ns short pulse laser, and then the ms long pulse laser or the ns short pulse laser is turned off to realize the single output of the ms long pulse laser and the ns short pulse laser.

In one embodiment, as shown in FIG6 , which is a schematic diagram of a pulse cluster composite pulse laser device with a dynamic detection function, the output method further includes:

The material detection device 17 disposed at the material to be cleaned 18 monitors the cleaning status of the material to be cleaned 18 in real time;

The material detection device 17 feeds back the real-time cleaning status to the information processing device 16;

The information processing device 16 sends a control signal to the signal generator 12 and the delay device 14 according to the real-time cleaning status to change the set value;

A pulse cluster output is achieved that matches the real-time cleaning status of the surface of the material 18 to be cleaned.

In one embodiment, it also includes:

The information processing device 16 is provided with an image recognition processing system, and the image recognition of the real-time state of the surface of the material to be cleaned 18 is completed according to the image recognition processing system;

According to the image recognition result, the morphological parameters of the area to be cleaned on the surface of the material to be cleaned 18 are determined;

A matching pulse cluster setting value is determined according to the morphology parameter.

Among them, the meaning and explanation of the technical features in the method of outputting laser using the pulse cluster composite pulse laser device are the same as the meaning and explanation of the technical features in the above laser, and will not be repeated here.

In the description of this specification, the terms "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific state.

In the description of this specification, the description of the terms "one embodiment", "some embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A pulse cluster composite pulse laser device, characterized in that it comprises: a first cavity mirror (1), a λ/4 wave plate (2), an RTP Q switch (3), a polarizer (4), a first pump module (5), a first laser crystal (6), a polarization beam splitter prism (7), an output mirror (8), a second pump module (9), a second laser crystal (10), an acousto-optic Q switch (11), a second cavity mirror (13), a signal generator (12), a time delay device (14), a laser detection device (15), and an information processing device (16), wherein: The first cavity mirror (1) and the output mirror (8) form a ms pulse laser linear resonant cavity, and the output mirror (8), the polarization beam splitter prism (7) and the second cavity mirror (13) form an L-shaped ns pulse laser resonant cavity; The λ/4 wave plate (2), the RTP Q switch (3), the polarizing plate (4), the first laser crystal (6), and the polarization beam splitter prism (7) are sequentially arranged between the first cavity mirror (1) and the output mirror (8); The acousto-optic Q switch (11) and the second laser crystal (10) are sequentially arranged between the second cavity mirror (13) and the polarization beam splitting prism (7); The first laser crystal (6) and the second laser crystal (10) are anisotropic laser crystals; The first pump module (5) is located on a side of the first laser crystal (6), and the second pump module (9) is located on a side of the second laser crystal (10); The signal generator (12) is electrically connected to the acousto-optic Q switch (11), and the signal generator (12) adjusts the amplitude of the radio frequency signal of the acousto-optic Q switch (11) by controlling a feedback voltage; The laser detection device (15) is located above the second cavity mirror (13); The information processing device (16) is electrically connected to the signal generator (12), the delay device (14) and the laser detection device (15); The delay device (14) is connected to the first pump module (5) and the second pump module (9); The incident surface of the polarization beam splitter prism (7) faces the first cavity mirror (1), the horizontal polarization output surface faces the output mirror (8), and the vertical polarization output surface faces the opposite direction of the second cavity mirror (13); The polarization direction of the polarizer (4) is horizontal; The fast axis of the λ/4 wave plate (2) also forms an angle of 45° with the horizontal direction. 2. The pulse cluster composite pulse laser device according to claim 1, characterized in that the first laser crystal (6) and the second laser crystal (10) are Nd: _YVO4 crystal, Nd:YAP crystal or Nd:YLF crystal. 3. The pulse cluster composite pulse laser device according to claim 2, characterized in that the output wavelength of the first pump module (5) and the second pump module (9) is 880nm, and the thermal boost pumping is directly pumped from the ground state energy level to the laser upper energy level. 4. The pulse cluster composite pulse laser device according to claim 3, characterized in that the output mirror (8), the first cavity mirror (1), and the second cavity mirror (13) are plane mirrors. 5. The pulse cluster composite pulse laser device according to claim 4 is characterized in that the surface of the output mirror (8) facing the resonant cavity is coated with a 1064nm anti-reflection film, and the surface facing away from the resonant cavity is coated with a 1064nm high-transmittance film with a transmittance of 20%; the first cavity mirror (1) is coated with 880nm and 1064nm total reflection films; the second cavity mirror (13) is coated with an 880nm total reflection film and a 1064nm high-transmittance film with a transmittance of 10%. 6. The pulse cluster composite pulse laser device according to claim 1 is characterized in that the pulse cluster composite pulse laser device also includes a material detection device (17), the material detection device (17) is arranged at the material to be cleaned (18), and is used to feedback the cleaning status of the material to be cleaned (18); the material detection device (17) is electrically connected to the information processing device (16), and is used to feed back the real-time cleaning status to the information processing device (16), and the information processing device (16) sends a control signal to the signal generator (12) and the delay device (14) according to the real-time cleaning status, so as to change the pulse cluster sequence output by the pulse cluster composite pulse laser device, so as to realize the pulse cluster output matching the real-time cleaning status of the surface of the material to be cleaned (18). 7. An output method of a pulse cluster composite pulse laser device, using the pulse cluster composite pulse laser device according to any one of claims 1 to 6, characterized in that it comprises: Selecting pulse cluster sequence parameters according to the material to be cleaned (18), and determining pulse cluster setting values, wherein the setting values include pulse cluster sequence parameters and output laser peak power; The first pump module (5) and the second pump module (9) emit pump light to side-pump the first laser crystal (6) and the second laser crystal (10); The first laser crystal (6) and the second laser crystal (10) absorb the pump light to form a particle beam inversion, resulting in stimulated radiation and generating 1064 nm laser; The 1064nm laser light propagating in the vertical direction only retains the vertical polarization after passing through the polarization beam splitter prism (7), and the 1064nm laser light propagating in the horizontal direction only retains the horizontal polarization after passing through the polarization beam splitter prism (7), and both are emitted through the output mirror (8); When there is no need to emit ms laser light, the RTP Q switch (3) is controlled so that no voltage is applied, and the 1064 nm laser light propagating in the horizontal direction becomes a horizontally polarized 1064 nm laser light after passing through the polarizer (4). After passing through the RTP Q switch (3) and the λ/4 wave plate (2), the 1064 nm laser light is reflected by the first cavity mirror (1). After passing through the λ/4 wave plate (2), the polarization state of the 1064 nm laser light is converted from horizontal polarization to vertical polarization. After passing through the RTP Q switch (3), the polarization state of the 1064 nm laser light is still vertically polarized and cannot pass through the polarizer (4); When it is necessary to emit ms laser light, the RTP Q switch (3) is controlled to load a λ/4 voltage, and the 1064nm laser light propagating in the horizontal direction becomes a horizontally polarized 1064nm laser light after passing through the polarizer (4). After passing through the RTP Q switch (3) and the λ/4 wave plate (2), the polarization state of the 1064nm laser light changes from horizontal polarization to vertical polarization. The vertically polarized 1064nm laser light is reflected by the first cavity mirror (1), and then passes through the λ/4 wave plate (2) and the RTP Q switch (3). The polarization state of the 1064nm laser light changes from vertical polarization to horizontal polarization. After passing through the polarizer (4), the first laser crystal (6), and the polarization beam splitter (7), the 1064nm laser light is emitted from the output mirror (8); When ns laser emission is required, the signal generator (12) externally connected to the acousto-optic Q switch (11) is controlled to place the acousto-optic Q switch (11) in a single-step mode, i.e., a conventional acousto-optic Q-switching mode, to achieve ns laser output; When it is necessary to obtain a pulse cluster with a ns interval, the signal generator (12) externally connected to the acousto-optic Q switch (11) is in a multi-step Q-switching state to achieve the output of sub-pulses with a ns interval in a short time domain; According to the set value, by controlling the delay device (14), the ms-ns interval composite pulse cluster laser duty cycle is adjusted and the sequential action is performed to achieve pulse cluster ms-ns time domain frequency composite point position matching; The output power and pulse width of the ns pulse cluster measured by the laser detection device (15) are transmitted to the information processing device (16) to calculate the peak power of the ns pulse cluster, and the information processing device (16) makes a determination according to the set value; When the information processing device (16) determines that the peak power is too high, the information processing device (16) transmits a signal to the signal generator (12), and the signal generator (12) increases the feedback voltage, thereby causing the amplitude of the radio frequency signal driving the acousto-optic Q switch (11) to decrease, thereby reducing the peak power; When the information processing device (16) determines that the peak power is too low, the information processing device (16) transmits a signal to the signal generator (12), and the signal generator (12) reduces the feedback voltage, thereby causing the amplitude of the radio frequency signal driving the acousto-optic Q switch (11) to increase, thereby increasing the peak power; When the information processing device (16) determines that the output laser peak power reaches the set value, peak power matching is achieved according to actual needs. 8. The output method according to claim 7, characterized in that it comprises: The delay device (14) can achieve a minimum delay control of 300 ps. The pulse cluster shape is determined according to the material to be cleaned (18), and the delay device (14) is adjusted to achieve ms and ns interval pulse cluster composite pulse output with adjustable duty cycle and action order; The delay device (14) is adjusted to achieve the first action of the ms long pulse laser, and after the ms long pulse output is turned off, the short ns pulse cluster is used to obtain a pulse cluster combination of ms-ns pulses; The delay device (14) is adjusted to achieve the first action of the ns short pulse laser, the action of the ms long pulse laser after the ns short pulse output is turned off, and the action of the short ns pulse cluster is used after the ms long pulse output is turned off to obtain a pulse cluster combination of ns-ms-ns pulses; The delay device (14) is adjusted to achieve the first action of the ns short pulse laser, and while maintaining the output of the ns short pulse laser, the ms long pulse laser is output to obtain the continuous action of the ms and ns pulse clusters; The delay device (14) is adjusted to achieve simultaneous output of ms long pulse laser and ns short pulse laser, and then the ms long pulse laser or the ns short pulse laser is turned off to achieve single output of ms long pulse laser and ns short pulse laser. 9. The output method according to claim 7, further comprising: A material detection device (17) disposed at the material to be cleaned (18) is used to monitor the cleaning status of the material to be cleaned (18) in real time; The material detection device (17) feeds back the real-time cleaning status to the information processing device (16); The information processing device (16) sends a control signal to the signal generator (12) and the delay device (14) according to the real-time cleaning status to change the set value; A pulse cluster output is achieved that matches the real-time cleaning state of the surface of the material to be cleaned (18). 10. The output method according to claim 9, further comprising: The information processing device (16) is provided with an image recognition processing system, and image recognition of the real-time state of the surface of the material to be cleaned (18) is completed according to the image recognition processing system; Determining the morphological parameters of the area to be cleaned on the surface of the material to be cleaned (18) according to the image recognition result; A matching pulse cluster setting value is determined according to the morphology parameter.