Laser waveguide assembly, laser generating device and laser ablation device

Abstract

The present invention relates to a laser waveguide component, a laser generating device and a laser ablation device, comprising a waveguide body and a reflective layer, wherein the waveguide body is a hollow structure, and the reflective layer covers the inner wall of the hollow structure; the waveguide body has a first end and a second end, the first end is used to receive laser pulses, and the second end is used to output laser pulses after being transmitted in the waveguide body; the inner diameter of the waveguide body is not less than the diameter of the input laser spot, and the cross-sectional area of ​​the waveguide body is funnel-shaped and gradually decreases from the first end to the second end. The first end with a larger cross-sectional area is conducive to collecting scattered light and avoiding energy waste, while the gradually decreasing second end is conducive to reducing the spot size, making the laser energy more concentrated and easier to couple with the rear-end optical transmission component; at the same time, the waveguide body with a hollow structure can provide a total reflection structure that excites multiple high-order modes, thereby achieving uniform light intensity in the cross-sectional area of ​​the light beam and reducing damage to the device.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a laser waveguide component, a laser generating device and a laser ablation device. Background Art

[0002] With the development and progress of laser science, lasers are being used in more and more fields, such as laser cutting, laser radar, laser ablation, etc., and laser utilization rate and laser intensity distribution are the ultimate direction of researchers' efforts. For example, laser ablation technology is a technology that guides laser pulses through optical fiber bundles to the diseased tissue in blood vessels for ablation. The technical problem with this technology is that high-energy laser pulses in the ultraviolet band will damage the optical fiber. The damage mechanism is that on the one hand, when the laser pulse is coupled from the laser to the optical fiber bundle, the energy density of the light exceeds the damage threshold of the quartz glass, causing damage to the optical fiber end face; on the other hand, when the laser pulse is transmitted in the optical fiber, the self-interference phenomenon caused by the coherent effect causes uneven distribution of light spot energy, which is easy to cause damage inside the optical fiber. On the other hand, stray light will appear during the transmission process of the laser, and the consumption of stray light leads to a decrease in laser utilization rate.

[0003] Therefore, how to improve the uniformity of the light spot energy distribution, reduce the damage of the light spot to the device, and how to improve the laser utilization rate have become technical problems that need to be solved urgently in this field. Summary of the Invention

[0004] Based on this, in response to the above problems, the present invention provides a laser waveguide component, a laser generating device and a laser ablation device, which have the characteristics of high optical efficiency, high spot uniformity and low damage to devices.

[0005] To achieve the above objectives, the present invention provides a laser waveguide assembly, comprising a waveguide body and a reflective layer, wherein the waveguide body is a hollow structure, and the reflective layer covers the inner wall of the hollow structure; the waveguide body has a first end and a second end, the first end is used to receive laser pulses, and the second end is used to output laser pulses after transmission in the waveguide body; the inner diameter of the waveguide body is not less than the diameter of the input laser spot, and the cross-sectional area of ​​the waveguide body gradually decreases from the first end to the second end. The laser waveguide assembly provided by the present invention has a funnel-shaped cross-sectional area that gradually decreases from the first end to the second end. Since laser light generates a certain amount of scattered light during transmission, the first end with a larger cross-sectional area is conducive to collecting the scattered light and avoiding energy waste, while the second end with a gradually decreasing cross-sectional area is conducive to reducing the spot size, making the laser energy more concentrated and easier to couple with the rear-end optical transmission component; at the same time, the hollow waveguide body can provide a total reflection structure that excites multiple high-order modes, achieving uniform light intensity in the beam cross section and reducing damage to the device.

[0006] In one embodiment, the waveguide body is filled with at least one of nitrogen, oxygen, helium, neon, argon, krypton, xenon, radon, water vapor, carbon dioxide and air.

[0007] In one embodiment, the reflectivity of the reflective layer is not less than 85%. After the laser pulse is input from the first end of the waveguide body, the light is continuously reflected in the hollow structure of the waveguide body under the action of the reflective layer, exciting two or more high-order modes.

[0008] In one embodiment, the coating includes any one of an aluminum coating, a silver coating, or a dielectric film.

[0009] In one embodiment, the inner cavity cross-section of the waveguide body is circular, square or regular hexagonal.

[0010] In one embodiment, the reflective layer is a reflective scattering layer.

[0011] In one embodiment, the laser generating device further includes a laser generator and an optical fiber, wherein the laser generator is used to generate laser pulses, and the optical fiber is connected to the first end of the waveguide body and is used to transmit the laser pulses generated by the laser generator to the waveguide body.

[0012] In one embodiment, the laser generating device further includes a laser generator, a scattering module and a focusing module, wherein the laser generator is used to generate laser pulses; the scattering module is used to diverge the laser, thereby reducing the spatial coherence of the laser pulses; and the focusing module is used to focus the diverged laser onto the first end of the waveguide body.

[0013] In one embodiment, the scattering module includes a scattering lens or a scattering lens array.

[0014] In one embodiment, the focal length of the focusing module is greater than 150 mm.

[0015] In one embodiment, a beam expander is further provided at the front end of the scattering module.

[0016] In one embodiment, the laser generator generates a laser with a wavelength of 300 nm to 400 nm.

[0017] In one embodiment, a laser generating device is provided, comprising the aforementioned laser waveguide assembly, a laser generator and a laser pulse stretcher, wherein the laser generator is used to generate laser pulses, and the laser pulse stretcher comprises N optical reflector groups, N-1 beam splitting elements, an S polarization polarization selective reflection module, a P polarization polarization selective reflection module and a beam combining device; the optical reflector group comprises a first reflector and a second reflector arranged opposite to each other, and after the laser pulse is input into the optical reflector group, it is reflected multiple times between the first reflector and the second reflector before being output, and the beam splitting element is provided. The laser pulse stretcher is located at the output end of the optical reflector group and is used to split the laser output from the optical reflector group into two laser beams. The first laser beam is incident on the S-polarization polarization selective reflection module, and the second laser beam is incident on the next optical reflector group. The S-polarization polarization selective reflection module is used to convert the received light beam into S-polarized light, and the P-polarization polarization selective reflection module is used to convert the received light beam into P-polarized light. The beam combining device is located at the rear end of the S-polarization polarization selective reflection module and the P-polarization polarization selective reflection module and is used to combine the S-polarized light and the P-polarized light and then output them through a converging lens. The laser pulse stretcher can ensure that the energy utilization rate of the laser is not lost while effectively widening the pulse width, reducing the peak power of the output pulse, and avoiding the adverse nonlinear effects and damage to optical components caused by excessive peak power, such as damage to the scattering module, focusing module, and waveguide components. At the same time, widening the width of the laser pulse can also avoid ionizing the air. The broadened laser pulse is then transmitted to the laser waveguide component through the scattering module, focusing module, etc. The final laser pulse has the advantages of high optical efficiency, high spot uniformity and low damage.

[0018] In one embodiment, the optical reflector assembly further includes an angle adjustment mirror, which is disposed at the head end and / or the tail end of the first reflector and / or the second reflector and is used to adjust the number of reflections of the laser pulse.

[0019] In one embodiment, the number N of the light reflecting mirror groups is an even number greater than or equal to 2, and the number of the beam splitting elements is N-1.

[0020] In one embodiment, the laser generator generates a laser with a wavelength of 300 nm to 400 nm.

[0021] In one embodiment, a laser generating device is also provided, including a laser generator and a laser pulse stretcher, wherein the laser generator is used to generate laser pulses, and the laser pulse stretcher includes N light reflector groups, N-1 beam splitting elements, an S polarization polarization selective reflection module, a P polarization polarization selective reflection module and a beam combining device; the light reflector group includes a first reflector and a second reflector arranged opposite to each other, and after the laser pulse is input into the light reflector group, it is reflected multiple times between the first reflector and the second reflector and then output, and the beam splitting element is arranged at the output end of the light reflector group, and is used to split the laser output by the light reflector group into two laser beams, one laser beam is incident on the S polarization polarization selective reflection module, and the other laser beam is incident on the next group of light reflector groups, and the S polarization polarization selective reflection module is used to generate laser pulses, and the laser pulse is incident on the next group of light reflector groups, and the S polarization polarization selective reflection module is used to generate laser pulses. The polarization reflection module is used to convert the received light beam into S-polarized light, and the P-polarization polarization selective reflection module is used to convert the received light beam into P-polarized light. The beam combining device is arranged at the rear ends of the S-polarization polarization selective reflection module and the P-polarization polarization selective reflection module, and is used to combine the S-polarized light and the P-polarized light, and then output them through a converging lens. The output end of the converging lens is connected to the laser waveguide component, and the waveguide component includes a waveguide body and a reflective layer. The waveguide body is a hollow structure, and the reflective layer covers the inner wall of the hollow structure; the waveguide body has a first end and a second end, the first end is used to receive laser pulses, and the second end is used to output laser pulses after transmission in the waveguide body; the inner diameter of the waveguide body is not less than the diameter of the input laser spot.

[0022] In one embodiment, a laser ablation device is provided, comprising the aforementioned laser waveguide assembly. The laser ablation device further comprises a laser catheter, which is connected to the laser waveguide assembly.

[0023] In one embodiment, a laser ablation device is provided, comprising the aforementioned laser generating device, wherein the laser ablation device further comprises a laser catheter connected to the laser waveguide assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of a laser generating device in one embodiment of the present invention;

[0025] Figure 2 This is a schematic structural diagram of a waveguide body having a circular inner cavity cross-section in one embodiment of the present invention;

[0026] Figure 3 Schematic diagram of the structure in which the inner cavity cross section of the waveguide body in one embodiment of the present invention is a regular hexagon;

[0027] Figure 4 is a structural schematic diagram of a light reflecting mirror assembly in one embodiment of the present invention;

[0028] Figure 5 Schematic diagram of the structure of a laser pulse stretcher in one embodiment of the present invention;

[0029] Figure 6 is a schematic structural diagram of a laser pulse stretcher in another embodiment of the present invention;

[0030] Figure 7 Schematic diagram of the structure of a laser ablation device in one embodiment of the present invention;

[0031] Figure 8 Schematic diagram of the structure of a laser ablation device in another embodiment of the present invention. DETAILED DESCRIPTION

[0032] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0035] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] like Figures 1 to 3As shown, this embodiment provides a laser waveguide assembly, comprising a waveguide body 101 and a reflective layer 102. The waveguide body 101 is a hollow structure, and the reflective layer 102 covers the inner wall of the hollow structure. The waveguide body 101 has a first end 1001 and a second end 1002. The first end 1001 is used to receive laser pulses, and the second end 1002 is used to output laser pulses after transmission within the waveguide body. The inner diameter of the waveguide body 101 is not less than the diameter of the input laser spot. The cross-sectional area of ​​the waveguide body 101 is a funnel shape that gradually decreases from the first end 1001 to the second end 1002. Since laser light generates a certain amount of scattered light during transmission, the larger cross-sectional area of ​​the first end helps to collect the scattered light and avoid energy waste. At the same time, the gradually decreasing cross-sectional area of ​​the second end helps to reduce the spot size, making the laser energy more concentrated and easier to couple. The hollow waveguide body can provide a total reflection structure that excites multiple high-order modes, achieving uniform light intensity across the beam cross section. The reflective layer is a reflective scattering layer, and the waveguide body 101 and the reflective layer 102 can be an integral structure. For example, a dielectric film, a reflective film structure, or a reflective scattering film structure material can be used to enclose a hollow structure, thereby forming a waveguide body 101 and the reflective layer 102 as an integral structure. Without limitation, the waveguide body 101 and the reflective layer 102 can also be a combination of two single structures.

[0040] In one embodiment, the hollow waveguide body 101 is filled with at least one of nitrogen, oxygen, helium, neon, argon, krypton, xenon, radon, water vapor, carbon dioxide, or air. The central region of the hollow waveguide body is air, which is used to transmit laser pulses and increases the spot area and uniformity of the spot energy distribution. This structure has the advantage that using a gas like air as a light-guiding medium prevents damage to the coupled end faces caused by the focused laser light and prevents damage to the waveguide's internal structure during transmission.

[0041] In one embodiment, the reflectivity of the reflective layer 102 is not less than 85%, and the reflectivity is, for example but not limited to, 86%, 88%, 91%, 93%, 96%, 97%, etc.

[0042] In one embodiment, the coating includes any one of an aluminum coating, a silver coating, or a dielectric film.

[0043] Among them, after the laser is transmitted to the laser waveguide assembly in the above embodiment, the laser pulse can excite two or more high-order modes. Specifically, in one embodiment, after the laser pulse enters the waveguide body 101, it is reflected by the reflective layer 102 to change the light orientation in the hollow structure of the waveguide body 101. The laser is continuously reflected by the reflective layer 102 in the waveguide body 101, causing the laser pulse to propagate disorderly in the hollow structure. At this time, since the hollow structure can support more light field modes, more high-order modes are excited, and then more than two high-order modes are excited, thereby improving the uniformity of the laser spot energy distribution. That is, compared with the input laser spot, the laser energy distribution after passing through the waveguide assembly is more uniform, while destroying the coherence of the laser pulse and reducing the damage caused by the high-energy laser pulse to devices such as optical fibers.

[0044] In one embodiment, the inner cavity cross-section of the waveguide body 101 is circular, square, regular hexagonal or any other shape.

[0045] In one embodiment, a laser generating device is provided, comprising the aforementioned laser waveguide assembly, a laser generator 201, and an optical fiber (not shown). The laser generator 201 is configured to generate laser pulses, and the optical fiber is connected to the first end 1001 of the waveguide body 101 and is configured to transmit the laser pulses generated by the laser generator 201 into the interior of the waveguide body 101. In this embodiment, the laser light output by the laser generator 201 is directly transmitted to the laser waveguide assembly via the optical fiber, where it is homogenized, making the output light more uniform and less likely to damage the device.

[0046] like Figure 7 As shown, in one embodiment, the laser generating device further includes a laser generator 201, a scattering module 202 and a focusing module 203. The laser generator 201 is used to generate laser pulses. The laser generator adopts a third harmonic Nd:YAG laser with a laser pulse wavelength of 355nm; the scattering module 202 is used to receive the laser pulses emitted by the laser generator, increase the laser divergence angle by scattering, and make the laser diverge, thereby reducing the spatial coherence of the laser pulse; the focusing module 203 is used to receive the scattered laser and focus the diverged laser to the first end of the waveguide body. Exemplarily, the focusing module 203 is a focusing lens.

[0047] In one embodiment, the scattering module 202 includes a scattering lens or a scattering lens array. The scattering lens has a light-transmitting surface 2021 on one side for receiving laser light and a light-scattering surface 2023 on the other side for scattering laser pulses. The light-scattering surface 2023 has various sizes, typically ranging from 100 to 1500 mesh, to provide varying degrees of scattering of the laser pulses. For example, the laser scattering lens is made of UV fused silica.

[0048] In one embodiment, the focal length of the focusing module 203 is greater than 150 mm. The long focal length can effectively prevent the laser pulse from ionizing the air.

[0049] In one embodiment, a beam expander (not shown) is further provided at the front end of the scattering module 202 to extend the service life of the scattering module.

[0050] In one embodiment, a laser generating device includes the aforementioned laser waveguide assembly, which is a hollow optical fiber composed of a quartz glass sleeve and an aluminum coating, wherein the aluminum coating is located on the inner wall of the quartz glass sleeve. The central region of the hollow waveguide is air, which is used to transmit laser pulses and serves to increase the spot area and improve the uniformity of the spot energy distribution. The advantage of this structure is that air, as the light-guiding medium, prevents damage to the coupling end face caused by the focused laser light and prevents damage to the waveguide's internal structure during transmission.

[0051] It can be seen that a slight amplification of the laser pulse energy will cause the peak power to rise rapidly. When the peak power reaches a certain level, it will cause gain saturation, resulting in inefficient amplification, adverse nonlinear effects, and damage to the life of the amplifier's optical components. Therefore, this embodiment proposes a laser generating device that can improve the efficiency of the optical system while stretching the output pulse to effectively avoid damage to system components caused by excessive peak power during the amplification process, and can also avoid excessive peak power leading to gain saturation and adverse nonlinear effects. Specifically, Figure 4-Figure 6As shown, in one embodiment, a laser generating device includes the aforementioned laser waveguide assembly, and also includes a laser generator and a laser pulse stretcher, wherein the laser generator is used to generate laser pulses, and the laser pulse stretcher includes N optical reflector groups 300, N-1 beam splitting elements 400, an S polarization polarization selective reflection module 500, a P polarization polarization selective reflection module 600 and a beam combining device 700; the optical reflector group 300 includes a first reflector 301 and a second reflector 302 arranged opposite to each other, and after the laser pulse 303 is input into the optical reflector group, it is reflected multiple times between the first reflector 301 and the second reflector 302 and then output, and the beam splitting element 400 is arranged at the output end of the optical reflector group 300, and is used to split the laser output from the optical reflector group 300 into two laser beams, one laser beam 40 1 is incident on the S-polarization polarization selective reflection module 500, and another laser beam 402 is incident on the next set of light reflectors 300. The S-polarization polarization selective reflection module 500 and the P-polarization polarization selective reflection module 600 are used to change the polarization state of the laser light. Specifically, the S-polarization polarization selective reflection module 500 is used to obtain polarized light from the received light beam and absorb or reflect the P-polarization light, ultimately transmitting only the S-polarization light forward. The P-polarization polarization selective reflection module 600 is used to obtain polarized light from the received light beam and absorb or reflect the S-polarization light, ultimately transmitting only the P-polarization light forward. The beam combining device 700 is disposed at the rear end of the S-polarization polarization selective reflection module 500 and the P-polarization polarization selective reflection module 600 and is used to combine the received S-polarized light and the P-polarized light, and then output them through a converging lens. Preferably, the beam splitting element 400 is a reflective transmissive mirror. The laser pulse stretcher can be arranged before the laser waveguide assembly. The combined laser beam can be directly output to the waveguide body or output to the scattering module and then transmitted to the waveguide body after processing. The combined laser can also be directly output to the optical fiber. The laser pulse stretcher can also be arranged after the laser waveguide assembly. The laser pulse is transmitted through the waveguide assembly and then enters the laser pulse stretcher for stretching. The laser pulse stretcher in this embodiment can ensure that the energy utilization rate of the laser is not lost while effectively stretching the pulse width, reducing the peak power of the output pulse, avoiding the adverse nonlinear effects and damage to optical components caused by excessive peak power, including damage to the scattering module, focusing module, and waveguide assembly. At the same time, widening the width of the laser pulse can also avoid ionizing the air. The stretched laser pulse is then transmitted to the laser waveguide assembly through the scattering module, focusing module, etc., and the final laser pulse has the advantages of high optical efficiency, high spot uniformity, and low damage.

[0052] In one embodiment, the laser generator is used to generate high-energy laser pulses in the ultraviolet band with a specific wavelength, and the typical wavelength of the laser pulses is 300nm to 400nm.

[0053] In one embodiment, the light reflector group 300 also includes an angle adjustment mirror 303, which is arranged at the head end and / or the end of the first reflector 301 and / or the second reflector 302, and is used to adjust the number of reflections of the laser pulse. The more reflections, the greater the pulse extension width, the smaller the peak power of the output pulse, and the smaller the adverse nonlinear effects and damage to the optical elements.

[0054] In one embodiment, the number N of the light reflector groups 300 is an even number greater than or equal to 2, and the number of the beam splitting elements 400 is N-1. Because the last laser pulse no longer requires beam splitting after entering the Nth light reflector group and exiting, the number of beam splitting elements is one less than the number of light reflector groups. Preferably, the number of light reflector groups 300 can be set to 2, 4, 6, 8, 10, etc.; the corresponding number of beam splitting elements 400 can be set to 1, 3, 5, 7, 9, etc.

[0055] The specific working principle is as follows: the laser generator is used to generate laser pulses. After the laser pulses are input into the first group of light reflectors 300, they are reflected multiple times between the first reflector 301 and the second reflector 302 and then output. After the delay of multiple reflections and output, the laser is split into two laser beams by the first beam splitting element 400. One laser beam 401 is incident on the S-polarization polarization selective reflection module 500, and the other laser beam 402 is incident on the next group of light reflectors 300. The laser entering the second group of light reflectors 300 is output after multiple reflections and then split into two laser beams by the second beam splitting element 400. One laser beam 401 is incident on the S-polarization polarization selective reflection module 500, and the other laser beam 402 is incident on the next group of light reflectors 300, and so on. The first N / 2 laser beams are converted into S-polarized light through the S-polarization polarization selective reflection module 500, and the later N / 2 laser beams are converted into P-polarized light through the P-polarization polarization selective reflection module 600. For example, the light reflection mirror group 300 is 8 groups, and the laser pulse is divided into 8 laser beams and passes through the S-polarization polarization selective reflection module 500 and the P-polarization polarization selective reflection module 600 in turn. The first four laser beams are converted into S-polarized light through the S-polarization polarization selective reflection module 500, and the last four laser beams are converted into P-polarized light through the P-polarization polarization selective reflection module 600. The beam combining device 700 is arranged at the rear end of the S-polarization polarization selective reflection module 500 and the P-polarization polarization selective reflection module 600, and is used to combine the S-polarized light and the P-polarized light, and then output them through the converging lens 800. Alternatively, the light reflecting mirror group 300 is 8 groups, and the laser pulse is divided into 8 laser beams, which pass through the S-polarization polarization selective reflection module 500 and the P-polarization polarization selective reflection module 600 in sequence. The 1st, 3rd, 5th, and 7th laser beams are converted into S-polarized light through the S-polarization polarization selective reflection module 500, and the 2nd, 4th, 6th, and 8th laser beams are converted into P-polarized light through the P-polarization polarization selective reflection module 600. The beam combining device 700 is arranged at the rear end of the S-polarization polarization selective reflection module 500 and the P-polarization polarization selective reflection module 600, and is used to combine the S-polarized light and the P-polarized light, and then output them through the converging lens 800. The reflector used in this embodiment requires small reflection loss, high surface optical quality, and a high damage threshold to avoid energy loss and beam quality degradation.

[0056] In one embodiment, a laser generating device is also provided, including a laser generator and a laser pulse stretcher, wherein the laser generator is used to generate laser pulses, and the laser pulse stretcher includes N light reflecting mirror groups 300, N-1 beam splitting elements 400, an S polarization polarization selective reflection module 500, a P polarization polarization selective reflection module 600 and a beam combining device 700; the light reflecting mirror group 300 includes a first reflecting mirror 301 and a second reflecting mirror 302 arranged opposite to each other, and after the laser pulse is input into the light reflecting mirror group 300, it is reflected multiple times between the first reflecting mirror 301 and the second reflecting mirror 302 and then output, and the beam splitting element 400 is arranged at the output end of the light reflecting mirror group 300, and is used to split the laser output by the light reflecting mirror group 300 into two laser beams, one laser beam 401 is incident on the S polarization polarization selective reflection module, and the other laser beam 402 is incident on the next group of light reflecting mirror groups 300, and the S polarization polarization selective reflection Module 500 is used to convert the received light beam into S-polarized light, and the P-polarization polarization selective reflection module 600 is used to convert the received light beam into P-polarized light. The beam combining device 700 is arranged at the rear end of the S-polarization polarization selective reflection module 500 and the P-polarization polarization selective reflection module 600, and is used to combine the S-polarized light and the P-polarized light, and then output them through the converging lens 800. The output end of the converging lens 800 is connected to the laser waveguide component, and the waveguide component includes a waveguide body 101 and a reflective layer 102. The waveguide body 101 is a hollow structure, and the reflective layer 102 covers the inner wall of the hollow structure; the waveguide body 101 has a first end 1001 and a second end 1002, the first end 1001 is used to receive laser pulses, and the second end 1002 is used to output laser pulses after transmission in the waveguide body 101; the inner diameter of the waveguide body 101 is not less than the diameter of the input laser spot. The difference of this embodiment is that the structure of the waveguide body 101 is not limited, and the cross-sectional area of ​​the waveguide body 101 can be equal, decrease from large to small, or increase from small to large from the first end to the second end.

[0057] like Figure 7-Figure 8As shown, in one embodiment, a laser ablation device is also provided, comprising the aforementioned laser waveguide assembly, the laser ablation device further comprising a laser catheter 30, the laser catheter 30 being connected to the laser waveguide assembly. The laser catheter 30 in this embodiment guides laser pulses to vascular lesion tissue for ablation. The laser pulses have high uniformity, can effectively ablate the lesion and reduce damage to the device. Preferably, a first convex lens 40 and a second convex lens 50 are further provided between the waveguide assembly and the laser catheter 30. Specifically, the first convex lens 40 and the second convex lens 50 are disposed behind the second end of the waveguide body 101. The first convex lens 40 and the second convex lens 50 are used to isolate the second end of the laser catheter to prevent powder sputtered by the laser hitting the metal fixture of the optical fiber catheter from flying into the waveguide assembly, thereby avoiding contamination of the waveguide assembly, resulting in reduced transmission efficiency and device damage. The first convex lens 40 and the second convex lens 50 are used to transmit the laser output from the waveguide assembly to the laser catheter 30.

[0058] In one embodiment, a laser ablation device is provided, comprising the aforementioned laser generating device, the laser ablation device further comprising a laser catheter 30, the laser catheter 30 being connected to the laser waveguide assembly. The laser catheter in this embodiment guides laser pulses to vascular lesions for ablation. The laser pulses have high energy and strong uniformity, effectively ablating the lesions. Furthermore, the laser pulses have good uniformity and, after pulse width expansion, ensure optical efficiency while avoiding damage to the device. Preferably, a first convex lens 40 and a second convex lens 50 are further provided between the waveguide assembly and the laser catheter 30. The first convex lens 40 and the second convex lens 50 have equal focal lengths. The first convex lens 40 and the second convex lens 50 are used to isolate the second end of the laser catheter to prevent powder sputtered by the laser hitting the metal fixture of the optical fiber catheter from flying into the waveguide assembly, thereby preventing contamination of the waveguide assembly, resulting in reduced transmission efficiency and device damage. Furthermore, the first convex lens 40 and the second convex lens 50 are used to transmit the laser output from the waveguide assembly to the laser catheter 30.

[0059] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all changes that fall within the meaning and range of equivalents of the claims be included in the present invention, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0060] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A laser generating device, comprising a laser waveguide assembly, the laser waveguide assembly comprising a waveguide body and a reflective layer, the waveguide body being a hollow structure, the reflective layer covering the inner wall of the hollow structure; the waveguide body having a first end and a second end, the first end being configured to receive laser pulses, and the second end being configured to output laser pulses after transmission within the waveguide body; the inner diameter of the waveguide body being no less than the diameter of an input laser spot, and the cross-sectional area of ​​the waveguide body gradually decreasing from the first end to the second end, characterized in that: It also includes a laser generator and a laser pulse stretcher, wherein the laser generator is used to generate laser pulses, and the laser pulse stretcher includes N light reflector groups, N-1 beam splitting elements, an S polarization polarization selective reflection module, a P polarization polarization selective reflection module and a beam combining device, where N is an even number greater than or equal to 2; the light reflector group includes a first reflector and a second reflector arranged opposite to each other, and after the laser pulse is input into the light reflector group, it is reflected multiple times between the first reflector and the second reflector before being output, and the beam splitting element is arranged at the output end of the light reflector group , used to split the laser output by the light reflector group into two laser beams, one laser beam is incident on the S-polarization polarization selective reflection module, and the other laser beam is incident on the next group of light reflector groups, the S-polarization polarization selective reflection module is used to convert the received light beam into S-polarized light, and the P-polarization polarization selective reflection module is used to convert the received light beam into P-polarized light, and the beam combining device is arranged at the rear end of the S-polarization polarization selective reflection module and the P-polarization polarization selective reflection module, and is used to combine the S-polarized light and the P-polarized light, and then output them through a converging lens.

2. A laser generating device according to claim 1, characterized in that: The optical reflector assembly further comprises an angle adjustment mirror, which is arranged at the head end and / or the tail end of the first reflector and / or the second reflector and is used to adjust the number of reflections of the laser pulse.

3. The laser generating device according to claim 1, wherein: It also includes an optical fiber, one end of which is connected to the laser generator, and the other end is connected to the first end of the waveguide body, for transmitting the laser pulse generated by the laser generator to the waveguide body.

4. A laser generating device according to claim 1, characterized in that: It also includes scattering module and focusing module, The scattering module is used to diverge the laser light, thereby reducing the spatial coherence of the laser pulse; The focusing module is used to focus the divergent laser light to the first end of the waveguide body.

5. A laser generating device according to claim 4, characterized in that: The scattering module includes a scattering lens or a scattering lens array.

6. The laser generating device according to claim 4, characterized in that: A beam expander is also provided at the front end of the scattering module.

7. The laser generating device according to claim 4, characterized in that: The focal length of the focusing module is greater than 150 mm.

8. A laser generating device, characterized in that: The invention comprises a laser generator and a laser pulse stretcher, wherein the laser generator is used to generate laser pulses, and the laser pulse stretcher comprises N light reflector groups, N-1 beam splitting elements, an S polarization polarization selective reflection module, a P polarization polarization selective reflection module and a beam combining device, wherein N is an even number greater than or equal to 2; the light reflector group comprises a first reflector and a second reflector arranged opposite to each other, and after the laser pulse is input into the light reflector group, it is reflected multiple times between the first reflector and the second reflector before being output, and the beam splitting element is arranged at the output end of the light reflector group, and is used to split the laser outputted by the light reflector group into two laser beams, one laser beam is incident on the S polarization polarization selective reflection module, and the other laser beam is incident on the next light reflector group, and the S polarization polarization selective reflection module is provided. Used to convert the received light beam into S-polarized light, the P-polarization polarization selective reflection module is used to convert the received light beam into P-polarized light, the beam combining device is arranged at the rear ends of the S-polarization polarization selective reflection module and the P-polarization polarization selective reflection module, and is used to combine the S-polarized light and the P-polarized light, and then output them through a converging lens. The output end of the converging lens is connected to the laser waveguide component, and the waveguide component includes a waveguide body and a reflective layer. The waveguide body is a hollow structure, and the reflective layer covers the inner wall of the hollow structure; the waveguide body has a first end and a second end, the first end is used to receive laser pulses, and the second end is used to output laser pulses after transmission in the waveguide body; the inner diameter of the waveguide body is not less than the diameter of the input laser spot.

9. The laser generating device according to claim 8, characterized in that: The optical reflector assembly further comprises an angle adjustment mirror, which is arranged at the head end and / or the tail end of the first reflector and / or the second reflector and is used to adjust the number of reflections of the laser pulse.

10. A laser generating device according to claim 1 or 8, characterized in that: The waveguide body is filled with at least one of nitrogen, oxygen, helium, neon, argon, krypton, xenon, radon, water vapor, carbon dioxide and air.

11. A laser generating device according to claim 1 or 8, characterized in that: The reflectivity of the reflective layer is not less than 85%. After the laser pulse is input from the first end of the waveguide body, the light is continuously reflected in the hollow structure of the waveguide body under the action of the reflective layer, exciting two or more high-order modes.

12. The laser generating device according to claim 11, characterized in that: The reflective layer is any one of an aluminum coating, a silver coating or a dielectric film.

13. A laser generating device according to claim 1 or 8, characterized in that: The reflective layer is a reflective scattering layer.

14. A laser generating device according to claim 1 or 8, characterized in that: The inner cavity cross section of the waveguide body is circular, square or regular hexagonal.

15. A laser generating device according to claim 1 or 8, wherein the laser wavelength generated by the laser generator is 300nm to 400nm.

16. A laser ablation device, characterized in that: A laser generating device comprising the laser generating device according to any one of claims 1 to 15.

17. The laser ablation device according to claim 16, characterized in that: The laser ablation device further comprises a laser catheter connected to the laser waveguide assembly.

18. The laser ablation device according to claim 16, characterized in that: A first convex lens and a second convex lens are further arranged between the laser waveguide assembly and the laser catheter.

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