Pulse width alternating change nanosecond laser output device and output method

Abstract

The invention relates to the technical field of laser, and provides a nanosecond laser output device and output method with alternately changing pulse widths, and the device comprises a laser gain module which is arranged in a resonant cavity and is used for radiating laser; the resonant cavity comprises a high-reflectivity mirror and an output mirror and is used for generating oscillation laser; the polaroid, the electro-optical Q switch and the acousto-optic Q switch are all arranged in the resonant cavity; the polaroid is used for controlling the polarization direction of the polarized light in the resonant cavity; the electro-optical Q switch generates ten-nanosecond laser pulse; the acousto-optic Q switch is used for generating hundred nanosecond laser pulses; the first controller is used for outputting a continuous signal or a periodic signal to control the laser gain module to be continuous pumping or quasi-continuous pumping; and the second controller and the third controller are respectively used for outputting periodic signals to control the electro-optical Q switch and the acousto-optic Q switch, and long pulses and short pulses appear alternately in a period. According to the invention, double nanosecond pulse laser alternating output of tens of nanoseconds and hundreds of nanoseconds of pulse laser can be realized.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a nanosecond laser output device with alternately changing pulse widths and an output method. Background Art

[0002] With the continuous development of laser technology, nanosecond pulsed lasers have been widely used in various fields due to their high peak power, short pulse width, and high energy density. Among them, decanon and 100-nanosecond pulsed lasers have outstanding performance in precision machining, industrial manufacturing, scientific research, and other fields due to their unique pulse width ranges and application advantages.

[0003] Among them, decanthosecond pulsed lasers, with their extremely high peak power and excellent spatiotemporal control capabilities, are widely used in high-precision processing and inspection. For example, in laser marking and micromachining, decanthosecond pulsed lasers can achieve high-precision surface treatment of materials such as metals and ceramics, effectively avoiding thermal damage to the substrate. Furthermore, decanthosecond lasers play a vital role in lidar, emitting pulsed light with high spatiotemporal resolution, enabling high-precision ranging and three-dimensional imaging.

[0004] Hundred-nanosecond pulse lasers, due to their longer pulse widths and higher single-pulse energy, are suitable for industrial processing with high power requirements and significant thermal effects. For example, in laser welding, cutting, and laser cleaning, they can effectively remove rust and oil stains from metal surfaces.

[0005] However, there is no pulse laser in the prior art that has the characteristics of both a ten nanosecond pulse laser and a hundred nanosecond pulse laser.

[0006] Therefore, how to output nanosecond pulses that have the characteristics of both hundreds of nanosecond pulses and tens of nanosecond pulses is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0007] The present invention provides a nanosecond laser output device and an output method with alternately changing pulse widths, which are used to realize continuous output of pulse intervals with different pulse widths.

[0008] The present invention provides a nanosecond laser output device with alternately changing pulse widths, comprising: A laser gain module is provided inside the resonant cavity; the laser gain module is used to radiate laser light; the resonant cavity includes a high-reflection mirror and an output mirror, which are used to generate oscillating laser light; A polarizer, an electro-optical Q-switch, and an acousto-optic Q-switch are all placed in the resonant cavity; the polarizer is used to control the polarization direction of polarized light in the resonant cavity; the electro-optical Q-switch is used to generate a laser pulse of tens of nanoseconds; and the acousto-optic Q-switch is used to generate a laser pulse of hundreds of nanoseconds; The first controller is used to output a continuous signal or a periodic signal to control the laser gain module to output continuous laser or quasi-continuous laser; The second controller and the third controller are used to output periodic signals to control the electro-optical Q switch and the acousto-optical Q switch respectively; and long pulses and short pulses appear alternately within a period.

[0009] According to a nanosecond laser output device with alternating pulse width provided by the present invention, the electro-optical Q switch adopts a boost-type Q-switching method and also includes a 1 / 4λ wave plate. When the voltage is low, the polarization direction of the laser traveling back and forth between the electro-optical Q switch and the 1 / 4λ wave plate is rotated by 90°, and when the voltage is high, the polarization direction remains unchanged.

[0010] According to a nanosecond laser output device with alternating pulse width provided by the present invention, the electro-optical Q switch adopts a de-voltage Q-switching method. When high voltage is applied, the polarization direction of the laser traveling back and forth from the electro-optical Q switch is rotated by 90°, and when low voltage is applied, the polarization direction remains unchanged.

[0011] According to a nanosecond laser output device with alternating pulse width provided by the present invention, the resonant cavity is a straight cavity type, the polarizer transmits polarized light in a first direction, and the polarized light in the first direction is horizontally polarized light.

[0012] According to a nanosecond laser output device with alternating pulse width provided by the present invention, the resonant cavity is in a ring form, the polarizer reflects polarized light in a second direction, and the second polarized light in the second direction is vertically polarized light; and an optical isolator is also included, and the optical isolator is placed in the resonant cavity to realize unidirectional operation of the oscillating laser.

[0013] According to a nanosecond laser output device with alternating pulse width provided by the present invention, the laser gain module adopts side pumping or end pumping; the laser gain module includes a laser gain medium and a pump light source, the laser gain medium is a laser crystal, glass or ceramic; the pump light source is a bar or a lamp.

[0014] According to the present invention, a nanosecond laser output device with alternating pulse width further includes a water cooling device, which is used to cool the laser gain module.

[0015] The present invention further provides a method for outputting a nanosecond laser with an alternating pulse width, using any of the above-mentioned nanosecond laser output devices with an alternating pulse width, comprising: Controlling the laser gain module to output continuous laser or quasi-continuous laser through the first controller; The second controller and the third controller respectively output periodic signals H to control the electro-optic Q switch and the acousto-optic Q switch, and long pulses and short pulses appear alternately within the period to achieve alternating output of nanosecond lasers with different pulse widths.

[0016] According to the present invention, a method for outputting nanosecond lasers with alternating pulse widths is provided, comprising: The first controller outputs a periodic signal to control the laser gain module to radiate oscillating laser as quasi-continuous pump laser, and the pulse light pulse time is t 81 ; The second controller outputs a periodic signal to control the electro-optical Q switch, and the pulse time of the second controller long pulse is the first long pulse time t 91 , the pulse time of the short pulse is the first short pulse time t 92 ; The third controller outputs a periodic signal to control the acousto-optic Q switch, and the pulse time of the long pulse is the second longest pulse time t 101 , the short pulse time is the second short pulse time t 102 ; Control the first long pulse time t 91 and the second longest pulse time t 101 The pulse width is consistent with the first long pulse time t 91 and the second longest pulse time t 101 The pulse time t 81 The time of the first short pulse is close to 92 and the second short pulse time t 102 The pulse time is much shorter than the pulse time t 81 ; Control the first long pulse time t 91 and the second short pulse time t 102 With a first delay time t 00 , ensuring that the second longest pulse time t 101 and the first short pulse time t 92 With a second delay time t 01 , In the case of continuous pumping, when the second short pulse time t 102 and the first long pulse time t 91 When the first short pulse time t 92 and the second longest pulse time t 101 When they appear simultaneously, the electro-optical Q-switched laser of ten nanoseconds is output; In the case of pulse pumping, when the second short pulse time t 102 , the first long pulse time t 91 and the pulse light pulse time t 81 When the first short pulse time t 92 , the second longest pulse time t101 and the pulse light pulse time t 81 When they appear at the same time, a tens-nanosecond electro-optical Q-switched laser is output.

[0017] According to the present invention, a method for outputting nanosecond lasers with alternating pulse widths further includes: adjusting the first delay time t 00 and the second delay time t 01 , which can change the interval time of laser pulses with different pulse widths.

[0018] The present invention provides a nanosecond laser output device and method with alternating pulse widths. This device and method employs a laser gain module, a polarizer, an electro-optical Q-switch, and an acousto-optic Q-switch within a single resonant cavity. The laser gain module is controlled by a first controller, the electro-optical Q-switch by a second controller, and the acousto-optic Q-switch by a third controller. The electro-optical Q-switch generates laser pulses in the tens of nanoseconds range, while the acousto-optic Q-switch generates laser pulses in the hundreds of nanoseconds range. Continuous laser output with varying pulse widths is achieved through rational control of electrical signals. This compact structure and simple design enable continuous dual-nanosecond pulse output of pulsed lasers in the tens of nanoseconds and hundreds of nanoseconds range, demonstrating its high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 Schematic diagram of a boosted straight-cavity pulsed laser device according to a first embodiment of the present invention; Figure 2 is a schematic diagram of nanosecond pulses with different pulse widths output according to the first embodiment of the present invention; Figure 3 is a schematic diagram of a decompressed ring cavity pulsed laser device according to a second embodiment of the present invention; Figure 4 FIG. 1 is a schematic diagram of nanosecond pulses with different pulse widths output according to the second embodiment of the present invention.

[0021] Reference numerals: 1. High-reflectivity mirror; 2. Laser gain module; 3. 1 / 4λ wave plate; 4. Polarizer; 5. Electro-optic Q-switch; 6. Acousto-optic Q-switch; 7. Output mirror; 8. First controller; 9. Second controller; 10. Third controller; 11. Optical isolator. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0023] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0024] The following combination Figures 1-4 The nanosecond laser output device with alternately changing pulse width of the present invention is described.

[0025] like Figure 1 and Figure 2 As shown, the nanosecond laser output device with alternating pulse width provided by an embodiment of the present invention includes a resonant cavity, a laser gain module 2, a polarizer 4, an electro-optical Q switch 5, an acousto-optic Q switch 6, a first controller 8, a second controller 9 and a third controller 10.

[0026] The resonant cavity includes a highly reflective mirror 1 and an output mirror 7. A laser gain module 2 is located within the resonant cavity; it radiates laser light, while the resonant cavity generates oscillating laser light. A polarizer 4, an electro-optical Q-switch 5, and an acousto-optic Q-switch 6 are all located within the resonant cavity. The polarizer 4 controls the polarization direction of the polarized light within the resonant cavity. The electro-optical Q-switch 5 generates laser pulses in the tens of nanoseconds, while the acousto-optic Q-switch 6 generates laser pulses in the hundreds of nanoseconds.

[0027] The laser gain module 2 includes a quasi-continuous operation semiconductor 808 nm laser pump source, a gain medium of Nd:YAG crystal, and outputs quasi-continuous 1064 nm laser by side pumping.

[0028] The gain medium is a Nd:YAG crystal rod with a doping concentration of 1% and a size of D3 mm × 80 mm. The crystal surface is coated with a high-transmittance film of 808 nm and 1064 nm (transmittance greater than 99%).

[0029] The first controller 8 is used to control the laser gain module 2 to be quasi-continuously pumped. The second controller 9 and the third controller 10 are used to output periodic signals to control the electro-optical Q switch 5 and the acousto-optic Q switch 6 respectively; and long pulses and short pulses appear alternately within the period.

[0030] In some feasible embodiments of the present invention, the electro-optical Q switch 5 adopts a boost-type Q-switching method and also includes a 1 / 4λ wave plate 3. When a 1 / 4λ voltage is applied, the polarization direction of the laser traveling back and forth between the electro-optical Q switch 5 and the 1 / 4λ wave plate 3 is rotated by 90° at low voltage, and the polarization direction remains unchanged at high voltage.

[0031] In other embodiments, the electro-optical Q switch 5 adopts a de-voltage Q-switching method. When the voltage is high, the polarization direction of the laser traveling to and from the electro-optical Q switch 5 is rotated by 90°, and when the voltage is low, the polarization direction remains unchanged.

[0032] In some feasible embodiments of the present invention, the resonant cavity is a straight cavity type, the polarizer 4 transmits polarized light in a first direction, and the polarized light in the first direction is horizontally polarized light.

[0033] In some feasible embodiments of the present invention, a water cooling device is further included, which is used to cool the laser gain module 2 to prevent the gain medium in the laser gain module 2 from being overheated, causing a decrease in the laser output power and beam quality.

[0034] In some feasible embodiments of the present invention, the laser gain module 2 adopts side pumping or end pumping; the laser gain module 2 includes a laser gain medium and a pump light source, the laser gain medium is a laser crystal, glass or ceramic; the pump light source is a bar or a lamp.

[0035] like Figure 2 As shown, the nanosecond laser output device with alternating pulse width provided by the present invention generates oscillating laser through the laser gain module 2; the first controller 8 outputs a periodic signal to control the laser gain module 2 to radiate quasi-continuous oscillation laser, radiates 1064nm laser through side pumping, oscillates to form laser in the resonant cavity, and the pulse light pulse time is t 81 = 200 μs, period H = 10 kHz. The polarizer 4 transmits horizontally polarized light, achieving 1064 nm fundamental frequency light operation of horizontally polarized light. The second controller 9 outputs a periodic signal to control the electro-optical Q switch 5, and the pulse time of the long pulse of the second controller 9 is the first long pulse time t 91 , the pulse time of the short pulse is the first short pulse time t 92 The third controller 10 controls the acousto-optic Q switch 6 to output a periodic signal, and the pulse time of the long pulse is the second long pulse time t 101 , the short pulse time is the second short pulse time t 102; Control the first long pulse time t 91 and the second longest pulse time t 101 The pulse width and pulse time t of the pulse light 81 The pulse width is consistent, the first short pulse time t 92 and the second short pulse time t 102 The pulse time is much shorter than the pulse light pulse time t 81 .

[0036] Control the first long pulse time t 91 and the second short pulse time t 102 With a first delay time t 00 , ensuring the second longest pulse time t 101 and the first short pulse time t 92 With a second delay time t 01 . Adjust the first delay time t 00 = second delay time t 01 =199 μs, first longest pulse time t 91 = second longest pulse time t 101 = pulse light pulse time t 81 =200 μs, first short pulse time t 92 = second short pulse time t 102 =1 μs, the second controller 9 and the third controller 10 output control signals to ensure the first long pulse time t 91 and the second longest pulse time t 101 Alternately, the first short pulse time t 92 and the second short pulse time t 102 Alternately; when the second short pulse time t 102 , first long pulse time t 91 and the pulse light pulse time is t 81 When the first short pulse time t 92 , the second longest pulse time t 101 and the pulse light pulse time is t 81 When these two lasers occur simultaneously, a tens-nanosecond electro-optical Q-switched laser is output. Thus, pulses with a 10 kHz pulse width of tens and hundreds of nanoseconds are output at intervals. Ultimately, a double-pulse nanosecond laser with different pulse widths is output through the output mirror 7.

[0037] Therefore, the above embodiment realizes the output of nanosecond pulses of two pulse widths through the electro-optical Q switch and the acousto-optic Q switch, adjusts the first controller 8 to realize the laser output of the laser gain module 2, and reasonably adjusts the delay time of the second controller 9 and the third controller 10 to output the Q-switched signal, thereby realizing the output of nanosecond pulses of the same pulse width and effective adjustment of the interval.

[0038] like Figure 3 and Figure 4 As shown, in other feasible embodiments of the present invention, the resonant cavity is a ring, and polarizer 4 reflects light polarized in the second direction, which is vertically polarized light. An optical isolator 11 is also included, positioned within the resonant cavity to achieve unidirectional operation of the oscillating laser. Electro-optical Q-switch 5 employs de-stressed Q-switching. At high voltage, the polarization direction of the laser traveling to and from the electro-optical Q-switch 5 rotates 90°, while at low voltage, the polarization direction remains unchanged.

[0039] In the above embodiment, the laser gain module 2 includes a continuously operating semiconductor 808 nm laser pump source, a gain medium of Nd:YAG crystal, and outputs quasi-continuous 1064 nm laser by side pumping.

[0040] The gain medium is a Nd:YAG crystal rod with a doping concentration of 5% and a size of D3 mm × 80 mm. The crystal surface is coated with a high-transmittance film of 808 nm and 1064 nm (transmittance greater than 99%).

[0041] The output mirror 7 is coated with a 1064 nm anti-reflection film, and the high-reflection mirror 1 is coated with a 1064 nm high-reflection film.

[0042] The first controller 8 outputs a signal to control the laser gain module 2 to radiate 1064 nm laser light by side pumping, and oscillates in the resonant cavity to form laser light with a pulse time of t 81 =200μs, and the period is H=10 kHz.

[0043] The second controller 9 outputs a signal to control the electro-optical Q switch 5, and the third controller 10 controls the acousto-optic Q switch 6. A 1 / 4λ voltage is used, which is a de-voltage Q-switching method. When high voltage is applied, the polarization direction of the laser traveling back and forth to the electro-optical Q switch 5 is rotated 90°. When low voltage is applied, the polarization direction remains unchanged, and laser pulses are output. The output laser is a 1064 nm tens of nanosecond pulse laser; the output laser from the acousto-optic Q switch 6 is a 1064 nm hundreds of nanosecond pulse laser.

[0044] Specifically, in this embodiment, the first controller 8 outputs a continuous signal to control the laser gain module 2 to radiate 1064 nm laser light through side pumping, and oscillates to form continuous laser light in the ring resonator. The polarizer 4 reflects vertical linear polarized light, achieving stable vertical linear polarized light 1064 nm fundamental frequency light operation. The electro-optical Q switch 5 and the acousto-optic Q switch 6 are placed in the resonant cavity, and the second controller 9 and the third controller 10 output control signals to control the output of Q-switched laser pulses. The second controller 9 and the third controller 10 output periodic signals, and long pulses and short pulses appear alternately with a period of H. Long pulses and short pulses are output alternately within the period, and the pulse time of the long pulse of the second controller 9 is the first long pulse time t91 , the pulse time of the short pulse is the first short pulse time t 92 , the pulse time of the third controller 10 long pulse is the second long pulse time t 101 , the pulse time of the short pulse is the second short pulse time t 102 The second controller 9 and the third controller 10 output control signals to ensure the first long pulse time t 91 and the second short pulse time t 102 With a certain delay time t 00 , ensuring the second longest pulse time t 101 and the first short pulse time t 92 With a certain delay time t 01 .

[0045] Adjust the relative delay time t 00 =190 us, t 01 =199 μs, first longest pulse time t 91 = second longest pulse time t 101 =200 μs, period H=10 kHz, first short pulse time t 92 = second short pulse time t 102 =1 μs, the second controller 9 and the third controller 10 output control signals to ensure the first long pulse time t 91 and the second longest pulse time t 101 Alternately, the second short pulse time t 102 and the first short pulse time t 92 Alternately; when the second short pulse time t 102 and the first long pulse time t 91 When the first short pulse time t 92 and the second longest pulse time t 101 When they appear at the same time, the electro-optical Q-switched laser of ten nanoseconds level is output, thereby outputting pulses of 2.08 kHz with pulse widths of ten nanoseconds level and one hundred nanoseconds level at intervals; finally, the double-pulse nanosecond laser with different pulse widths is output through the output mirror 7, as shown Figure 4 shown.

[0046] It should be noted that, during the first long pulse time t 91 , the second longest pulse time t 101 , first short pulse time t 92 , the second short pulse time t 102 During this time, the electro-optical Q switch 5 and the acousto-optical Q switch 6 need to remain in the open state.

[0047] In this embodiment, the ring resonator includes a highly reflective mirror 1, a polarizer 4, an optical isolator 11, and an output mirror 7. It achieves nanosecond pulse output with two different pulse widths through an electro-optical Q-switch 5 and an acousto-optic Q-switch 9. Laser output from the laser gain module 2 is achieved by adjusting the first controller 8. Simultaneously, the delay time of the Q-switched signals output by the second controller 9 and the third controller 10 is appropriately adjusted to achieve stable output of nanosecond pulses of the same pulse width and effective adjustment of the interval. Consequently, the device offers the advantages of a compact structure, high conversion efficiency of Q-switched dual-pulse lasers, and efficient and stable polarization-mode operation.

[0048] A second aspect of the present invention further provides a method for outputting a nanosecond laser with an alternating pulse width, using the aforementioned nanosecond laser output device with an alternating pulse width, comprising: Controlling the laser gain module 2 to output continuous laser or quasi-continuous laser through the first controller; The second controller and the third controller respectively output periodic signals H to control the electro-optic Q switch and the acousto-optic Q switch, and long pulses and short pulses appear alternately within the period to achieve alternating output of nanosecond lasers with different pulse widths.

[0049] Furthermore, the first controller 8 outputs a periodic signal to control the laser gain module 2 to radiate oscillating laser light, and the pulse time of the pulse light is t 81 The second controller 9 controls the electro-optical Q switch to output a periodic signal, and the second controller 9 has a long pulse time of the first long pulse time t 91 , the pulse time of the short pulse is the first short pulse time t 92 The third controller 10 controls the acousto-optic Q switch to output a periodic signal, and the pulse time of the long pulse is the second long pulse time t 101 , the short pulse time is the second short pulse time t 102 .

[0050] Control the first long pulse time t 91 and the second longest pulse time t 101 The pulse width is consistent with the first long pulse time t 91 and the second longest pulse time t 101 The pulse time t 81 The time of the first short pulse is close to 92 and the second short pulse time t 102 The pulse time is much shorter than the pulse time t 81 ; First short pulse time t 92 and the second short pulse time t 102 The pulse time is much shorter than the pulse light pulse time t 81 ; Control the first long pulse time t 91 and the second short pulse time t102 With a first delay time t 00 , ensuring the second longest pulse time t 101 and the first short pulse time t 92 With a second delay time t 01 .

[0051] In the case of continuous pumping, when the second short pulse time t 102 and the first long pulse time t 91 When the first short pulse time t 92 and the second longest pulse time t 101 When they appear simultaneously, the electro-optical Q-switched laser of ten nanoseconds is output; In the case of pulse pumping, when the second short pulse time t 102 , the first long pulse time t 91 and the pulse light pulse time t 81 When the first short pulse time t 92 , the second longest pulse time t 101 and the pulse light pulse time t 81 When they appear at the same time, a tens-nanosecond electro-optical Q-switched laser is output.

[0052] In some feasible embodiments of the present invention, the present invention further includes: Adjust the first delay time t 00 and the second delay time t 01 , which can change the interval time of laser pulses with different pulse widths.

[0053] The nanosecond laser output method with alternately changing pulse widths provided by the present invention can realize alternate output of pulse intervals with different pulse widths.

[0054] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or modes and features of different embodiments or modes described in this specification without contradiction.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A nanosecond laser output device with alternating pulse width, characterized in that: include: A laser gain module (2) is arranged inside the resonant cavity; the laser gain module (2) is used to radiate laser light; the resonant cavity comprises a high-reflection mirror (1) and an output mirror (7) for generating oscillating laser light; A polarizer (4), an electro-optical Q switch (5), and an acousto-optical Q switch (6) are all placed in the resonant cavity; the polarizer (4) is used to control the polarization direction of polarized light in the resonant cavity; the electro-optical Q switch (5) is used to generate a laser pulse of the order of ten nanoseconds; and the acousto-optical Q switch (6) is used to generate a laser pulse of the order of one hundred nanoseconds; A first controller (8) is used to output a continuous signal or a periodic signal to control the laser gain module (2) to output continuous laser light or quasi-continuous laser light; The second controller (9) and the third controller (10) are used to output periodic signals to control the electro-optical Q switch (5) and the acousto-optical Q switch (6), respectively; and long pulses and short pulses appear alternately within the period.

2. The nanosecond laser output device with alternately changing pulse width according to claim 1, characterized in that: The electro-optical Q switch (5) adopts a boost-type Q-switching method and also includes a 1 / 4λ wave plate (3). When the voltage is low, the polarization direction of the laser traveling back and forth between the electro-optical Q switch (5) and the 1 / 4λ wave plate (3) is rotated by 90°, and when the voltage is high, the polarization direction remains unchanged.

3. The nanosecond laser output device with alternately changing pulse width according to claim 1, characterized in that: The electro-optical Q switch (5) adopts a de-stressed Q-switching method. When the voltage is high, the polarization direction of the laser traveling back and forth from the electro-optical Q switch (5) is rotated by 90 degrees, and when the voltage is low, the polarization direction remains unchanged.

4. The nanosecond laser output device with alternately changing pulse width according to claim 1, characterized in that: The resonant cavity is a straight cavity type, and the polarizer (4) transmits polarized light in a first direction, and the polarized light in the first direction is horizontally polarized light.

5. The nanosecond laser output device with alternately changing pulse width according to claim 1, characterized in that: The resonant cavity is in a ring form, the polarizer (4) reflects polarized light in a second direction, and the polarized light in the second direction is vertically polarized light; and an optical isolator (11) is also included, and the optical isolator (11) is placed in the resonant cavity to achieve unidirectional operation of the oscillating laser.

6. The nanosecond laser output device with alternately changing pulse width according to any one of claims 1 to 5, characterized in that: The laser gain module (2) adopts side pumping or end pumping; the laser gain module (2) comprises a laser gain medium and a pump light source, the laser gain medium is a laser crystal, glass or ceramic; the pump light source is a bar or a lamp.

7. The nanosecond laser output device with alternately changing pulse width according to any one of claims 1 to 5, characterized in that: It also includes a water cooling device, which is used to cool the laser gain module (2).

8. A nanosecond laser output method with alternating pulse width, characterized in that: A nanosecond laser output device with alternately changing pulse width according to any one of claims 1 to 7, characterized in that it comprises: Controlling the laser gain module (2) to output continuous laser or quasi-continuous laser through a first controller; The second controller (9) and the third controller (10) respectively output periodic signals H to control the electro-optical Q switch (5) and the acousto-optical Q switch (6), and long pulses and short pulses appear alternately within the period to achieve alternate output of nanosecond lasers with different pulse widths.

9. The method for outputting nanosecond lasers with alternating pulse widths according to claim 8, wherein: include: The first controller (8) outputs a periodic signal to control the laser gain module (2) to radiate oscillating laser light, and the pulse time of the pulse light is t 81 ; The second controller (9) outputs a periodic signal to control the electro-optical Q switch (5), and the pulse time of the long pulse of the second controller (9) is the first long pulse time t 91 , the pulse time of the short pulse is the first short pulse time t 92 ; The third controller (10) outputs a periodic signal to control the acousto-optic Q switch (6), and the pulse time of the long pulse is the second long pulse time t 101 , the short pulse time is the second short pulse time t 102 ; Control the first long pulse time t 91 and the second longest pulse time t 101 The pulse width is consistent with the first long pulse time t 91 and the second longest pulse time t 101 The pulse light pulse time t 81 The time of the first short pulse is close to 92 and the second short pulse time t 102 The pulse time is much shorter than the pulse light pulse time t 81 ; Control the first long pulse time t 91 and the second short pulse time t 102 With a first delay time t 00 , ensuring that the second longest pulse time t 101 and the first short pulse time t 92 With a second delay time t 01 , In the case of continuous pumping, when the second short pulse time t 102 and the first long pulse time t 91 When the first short pulse time t 92 and the second longest pulse time t 101 When they appear simultaneously, the electro-optical Q-switched laser of ten nanoseconds is output; In the case of pulse pumping, when the second short pulse time t 102 , the first long pulse time t 91 and the pulse light pulse time t 81 When the first short pulse time t 92 , the second longest pulse time t 101 and the pulse light pulse time t 81 When they appear at the same time, a tens-nanosecond electro-optical Q-switched laser is output.

10. The nanosecond laser output method with alternating pulse width according to claim 8, characterized in that: Also includes: Adjust the first delay time t 00 and the second delay time t 01 , which can change the interval time of laser pulses with different pulse widths.

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