Optical fiber combining-coupled ultraviolet laser ablation system

Abstract

An optical fiber combining-coupled ultraviolet laser ablation system, comprising a laser (1), a light homogenizing assembly (2), and an optical fiber combining assembly (3). The laser (1) is used for emitting laser light. The light homogenizing assembly (2) is arranged on an emergent light path of the laser light. The optical fiber combining assembly (3) is arranged on an emergent light path of the light homogenizing assembly (2). The light homogenizing assembly (2) is used for performing beam flat-top shaping and beam superposition on the laser light to obtain a target light spot. The optical fiber combining assembly (3) is used for performing multi-beam transmission on the target light spot, so that laser ablation can be efficiently and stably achieved.

Description

A fiber beam-coupled ultraviolet laser ablation system Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an optical fiber beam combining and coupling ultraviolet laser ablation system. Background Art

[0002] Symptoms such as chronic occlusive lesions, thrombosis and their coexisting atherosclerotic plaques and calcified tissue lesions in blood vessels are generally treated through arterial intervention. The instrument catheter is delivered into the blood vessel, and the principle of laser ablation is used to eliminate plaques and proliferative tissue, thereby unblocking the occluded or narrowed blood vessels and achieving the effect of safe treatment without damaging the blood vessels.

[0003] Lasers acting on biological tissues produce a range of biological effects, including photochemical, thermal, and mechanical. Ultraviolet lasers with high peak power pulses and nanosecond pulse widths possess high photon energy, which can directly disrupt chemical bonds between biological tissue molecules and break down macromolecular compounds into small fragments, such as particles less than 20 μm. These fragments are ultimately absorbed by the reticuloendothelial system, thus preventing microvascular obstruction. When 355 nm ultraviolet lasers ablate thrombi and other pathological tissues, photochemical effects play a primary role, with minimal thermal effects.

[0004] The relatively small diameter of current UV laser ablation catheters limits the number and area of ​​ablation fibers that can be accommodated within them. This restricts the laser energy available at the fiber's entrance and easily damages the fiber's end face, resulting in suboptimal tissue ablation results. Therefore, improving fiber coupling efficiency and delivering stable laser energy without damaging the fiber's entrance end face is crucial.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to provide a fiber beam combining and coupling ultraviolet laser ablation system, which can realize laser ablation efficiently and stably.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A fiber beam combining coupled ultraviolet laser ablation system, the system comprising: a laser, a light homogenizing component and a fiber beam combining component;

[0009] The laser is used to emit laser light;

[0010] The light homogenizing component is arranged on the outgoing light path of the laser; the optical fiber combining component is arranged on the outgoing light path of the light homogenizing component;

[0011] The light homogenization component is used to perform beam flattening and beam superposition on the laser to obtain a target light spot;

[0012] The optical fiber beam combining assembly is used to perform multi-beam transmission on the target light spot.

[0013] Optionally, the light homogenizing component includes: a diffraction optical component.

[0014] Optionally, the diffractive optical component is a holographic diffuser.

[0015] Optionally, the light homogenization component includes:

[0016] a microlens group, arranged on the outgoing optical path of the laser, for performing flat-top shaping on the laser beam to obtain a shaped beam;

[0017] A focusing lens is provided on the outgoing optical path of the shaped light beam and is used for performing beam superposition on the shaped light beam to obtain the target light spot.

[0018] Optionally, the focusing lens is a plano-convex lens or a biconvex lens.

[0019] Optionally, the optical fiber combining assembly includes: a large core diameter quartz optical fiber, a bundled input optical fiber, a tapered bundled optical fiber, and a bundled output optical fiber;

[0020] The large-core quartz optical fiber is arranged on the output light path of the light homogenizing component; the large-core quartz optical fiber is connected to the tapered beam-combining optical fiber via the bundle input optical fiber; the output end of the tapered beam-combining optical fiber is connected to the bundle output optical fiber.

[0021] Optionally, the bundled input optical fiber includes multiple bundles of small-core quartz optical fibers.

[0022] Optionally, the core diameter of the large-core quartz optical fiber is greater than 600 μm.

[0023] Optionally, the core diameter of the small-core quartz optical fiber is less than 200 μm.

[0024] Optionally, the optical fiber combining assembly includes: a protective cover;

[0025] The protective sleeve is coated on the surface of the large-core quartz optical fiber.

[0026] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0027] The present invention provides a fiber-optic beam-combining coupled ultraviolet laser ablation system, which includes: a laser, a light-homogenizing component and a fiber-optic beam-combining component; the laser is used to emit laser light; the light-homogenizing component is arranged on the output light path of the laser; the fiber-optic beam-combining component is arranged on the output light path of the light-homogenizing component; the light-homogenizing component is used to perform beam flattening and beam superposition on the laser to obtain a target light spot; the fiber-optic beam-combining component is used to perform multi-beam transmission to the target light spot; since the light-homogenizing component performs beam flattening and beam superposition, the laser energy can be evenly distributed, and then the fiber-optic beam-combining component performs multi-beam transmission to the target light spot, which increases the receiving area, thereby avoiding damage to the incident light and achieving the purpose of evenly applying energy. Therefore, laser ablation can be achieved efficiently and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only 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.

[0029] FIG1 is a structural diagram of a fiber beam combining and coupling ultraviolet laser ablation system provided in an embodiment of the present invention;

[0030] FIG2 is a schematic diagram of an optical fiber combining assembly provided in an embodiment of the present invention;

[0031] FIG3 is a schematic diagram of the cross-sectional structure of a bundled input optical fiber provided in an embodiment of the present invention;

[0032] FIG4 is a schematic diagram of a bundled output optical fiber provided in an embodiment of the present invention;

[0033] FIG5 is a schematic diagram of an ablation system in actual application.

[0034] Explanation of symbols:

[0035] Laser 1, light homogenization assembly 2, fiber beam combining assembly 3, large-core quartz fiber 4, bundled input fiber 5, tapered bundle combining fiber 6, bundled output fiber 7, quartz capillary 8, small-core quartz fiber 9, connector 10, handle 11, output port 12, guide wire 13, microlens assembly 14, focusing lens 15. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 making creative efforts are within the scope of protection of the present invention.

[0037] The purpose of the present invention is to provide a fiber beam combining and coupling ultraviolet laser ablation system, which can realize laser ablation efficiently and stably.

[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] As shown in FIG1-FIG5 , an embodiment of the present invention provides a fiber beam combining coupled ultraviolet laser ablation system, which includes: a laser 1 , a light homogenizing component 2 and a fiber beam combining component 3 .

[0040] Laser 1 is used to emit laser; light homogenizing component 2 is arranged on the output light path of the laser; optical fiber combining component 3 is arranged on the output light path of light homogenizing component 2; light homogenizing component 2 is used to flat-top shape and superimpose the laser beam to obtain a target light spot; optical fiber combining component 3 is used to perform multi-beam transmission of the target light spot.

[0041] Specifically, the light homogenizing component 2 includes a diffraction optical component which is a holographic diffuser.

[0042] The light homogenization assembly 2 includes a microlens group 14 and a focusing lens 15. The microlens group 14 is arranged on the outgoing optical path of the laser beam, and the focusing lens 15 is arranged on the outgoing optical path of the shaped beam. The focusing lens 15 is a plano-convex lens or a biconvex lens.

[0043] The microlens group 14 is used to perform flat-top shaping on the laser beam to obtain a shaped beam; the focusing lens 15 is used to perform beam superposition on the shaped beam to obtain a target light spot.

[0044] The optical fiber combining assembly 3 includes: a large core diameter quartz optical fiber 4, a bundled input optical fiber 5, a tapered combined optical fiber 6 and a bundled output optical fiber 7.

[0045] The large-core quartz optical fiber 4 is arranged on the outgoing light path of the light homogenizing component 2 ; the core diameter of the large-core quartz optical fiber 4 is greater than 600 μm.

[0046] The large-core silica fiber 4 is connected to the tapered fiber 6 via the bundled input fiber 5. The output end of the tapered fiber 6 is connected to the bundled output fiber 7. The bundled input fiber 5 includes multiple small-core silica fibers 9. The core diameter of the small-core silica fibers 9 is less than 200 μm.

[0047] In one embodiment, the optical fiber combining assembly 3 further includes a protective sleeve, which covers the surface of the large-core quartz optical fiber 4 .

[0048] In practical applications, the wavelength of the ultraviolet laser is selected to be in the range of 200nm-400nm. The light homogenizing assembly 2 is a coupling device that receives the ultraviolet laser energy, and the fiber beam combiner 3 is a conductor device for transmitting the laser energy. As the laser passes through the array composed of microlenses 14, the microlenses 14 perform beam flattening and split the input laser spot. The subsequent focusing lens 15 then superimposes the multiple small beams of the split spot, thereby obtaining a homogenized light field distribution. This reduces the laser energy intensity per unit area received by the fiber input end, thereby avoiding damage to the end face of the input end and forming a uniform target spot.

[0049] Through the fiber optic beam combining component 3, the fiber core numerical aperture range is 0.22-0.50. Through the laser ablation catheter, that is, fusion splicing, the laser energy is effectively transmitted from a single large-core optical fiber with a core diameter of more than 600μm to multiple small-core optical fibers, ultimately realizing a compact laser ablation system with uniform light spot distribution and integrated fiber coupling.

[0050] The fiber combining assembly 3 connects a large core diameter silica fiber 4 to a tapered combined fiber 6 via a bundled input fiber 5 by fusion splicing. The bundled input fiber 5 includes multiple bundles of small core diameter silica fibers 9. A silica capillary 8 is used to bundle the multiple bundles of small core diameter silica fibers 9.

[0051] The tapered fiber 6 is encased in a quartz capillary 8, effectively transmitting laser energy from a single large-core fiber to multiple small-core quartz fibers 9, each with a core diameter of less than 200 μm. The fiber bundle, composed of multiple small-core quartz fibers 9, includes an input end, a tapered end, and an output end. The tapered ends have different diameters, with the large end connected to the output end and the small end connected to the input end. Both the tapered and input ends are located within the front end of the quartz capillary 8, while the output end extends outward from the rear end of the capillary 8. The large-core quartz fiber 4 is positioned behind a focusing lens 15 in the optical path. A microlens group 14 homogenizes the laser energy emitted by the laser 1, and the large-core quartz fiber 4 receives the homogenized laser light.

[0052] The laser 1 has a pulse width of less than 15 nanoseconds or sub-nanoseconds, and a wavelength of 200nm-400nm. The light homogenization component 2 can be provided with one or two microlens arrays. The light homogenization component 2 can be a diffractive optical element. Furthermore, the light homogenization component 2 can be a holographic diffuser. The focusing lens 15 is a plano-convex lens or a biconvex lens.

[0053] Furthermore, a protective sleeve can be coated on the surface of the large-core quartz optical fiber 4 and the quartz capillary 8. The optical fiber combining assembly 3 can also be configured as an SMA optical fiber connector, with the large-core quartz optical fiber 4 connected to one end of the optical fiber connector and the tapered combined optical fiber 6 connected to the other end. Furthermore, the optical fiber combining assembly 3 can be configured as a single tapered optical fiber bundle.

[0054] Current research has found that the effective energy density of the UV laser ablation system needs to reach 40mJ / mm 2 -60mJ / mm 2 The high peak energy of a nanosecond pulse width ultraviolet laser with a wavelength of 355nm will directly damage the end face of the optical fiber incident end, making it difficult to achieve optical fiber coupling. Large-core quartz optical fiber 4 is usually used as a conductor, but due to the large bending radius of the optical fiber, it cannot be used as a laser ablation catheter for intravascular treatment. Multiple bundles of small-core quartz optical fibers 9 are used as the conductor of the catheter. Since small-core optical fibers are soft and have a smaller bending radius, they can be used for laser ablation in blood vessels.

[0055] The optical fiber combining assembly 3 is used as the final conductor, and the front end is a single large-core quartz optical fiber 4, which can better transmit the homogenized laser energy to the small-core quartz optical fiber 9 and avoid directly damaging the end faces of multiple optical fibers.

[0056] Furthermore, the ablation fiber can be a single, larger-core-diameter fiber or a bundle of multiple UV multimode fibers. The single, large-core-diameter quartz fiber 4 offers superior structural strength and is less susceptible to breakage during use. The UV multimode fiber used in the fiber-combining assembly 3 effectively ensures stable operating performance. Each has its own advantages, and the choice can be made based on practical needs.

[0057] The fiber beam combining and coupling ultraviolet laser ablation system provided by the present invention solves the problems encountered in fiber coupling and can be applied to ultraviolet light with a wavelength of 266 nm or other common wavelengths of light, such as 1064 nm.

[0058] Figure 2 is a schematic diagram of a fiber-combining assembly, comprising a single large-core silica fiber 4, a bundled input fiber 5, a tapered bundled fiber 6, and a bundled output fiber 7. The bundled input fiber 5 is composed of multiple bundles of small-core silica fibers 9, which are bundled together. The tapered bundled fiber 6 is located at the output side of the bundled input fiber 5. The tapered end face of the bundled input fiber 5 is fused to one end of the large-core silica fiber 4. The fused bundled output fiber 7 serves as the output of the fiber-combining assembly 3. To improve the coupling efficiency between the bundled output fiber 7 and the large-core silica fiber 4, it is preferred that the core diameter of the large-core silica fiber 4 be similar to the core diameter of the combined bundled input fiber 5.

[0059] The bundled input optical fiber 5 includes multiple input optical fibers. In some embodiments, the multiple input optical fibers are composed of multiple power transmission optical fibers. As shown in the cross-sectional structural diagram of Figure 3, the bundled input optical fiber 5 is composed of at least 7 power transmission optical fibers, and the core diameter range is below 200μm. The method of optical fiber bundling mainly uses a quartz capillary 8, including a circular capillary, wherein the circular capillary has an inner diameter of 0.80mm-1.00mm, an outer diameter of 1.05mm-1.25mm, and a length of 100mm-200mm. After removing the coating layer of multiple small-core quartz optical fibers 9, they are inserted into a preset low-refractive index fluorine-doped glass tube. In some embodiments, after removing the coating layer at one end of the 7 optical fibers, the bare optical fibers are neatly arranged in a regular hexagon and all inserted into the low-refractive index glass tube; the end face arrangement structure of the optical fibers after the 7 optical fibers are bundled is shown in Figure 3. After the optical fiber is bundled, a fusion taper is performed on the predetermined area on the input side of the bundled input optical fiber 5, and the length of the taper area is determined to be 10mm-30mm, for example, 20mm. The output end interface diameter is tapered to about 450μm-750μm, and in some embodiments, 600μm. After the optical fiber bundle is hot-melted at high temperature on the fusion splicer, the optical fiber bundle is tightly fixed and arranged together. After the fusion taper is completed, a large-core fiber cleaver is used to cut the tapered waist area, and the cut end face is shown in Figure 3. Then, the carbon dioxide laser fusion method is used to fuse the cut optical fiber bundle taper end face with one end of the large-core quartz optical fiber 4.

[0060] FIG4 is a schematic diagram of a laser catheter, i.e., a bundled output optical fiber 7, according to an embodiment of the present invention. The connecting end 10 of the laser catheter is provided with the aforementioned large-core quartz optical fiber 4. The laser catheter uses the large-core quartz optical fiber 4 as a connector, which can be conveniently connected to the laser light homogenization component 2. Moreover, because the optical fiber in the front-end laser catheter is not fixed with an adhesive, high-energy, short-pulse-width, and effective ablation treatment can be achieved, and the thermal impact of the laser on human tissue is reduced. The Y-shaped handle 11 of the laser catheter is provided with the aforementioned optical fiber beam combining component 3. The laser catheter uses the optical fiber beam combining component 3 as a conductor device to effectively conduct the light beam to the rear end of the laser catheter, which serves as the output port 12 of the laser catheter. As a possible embodiment, the interior of the laser catheter cavity includes an ablation optical fiber and a guide wire 13. The ablation optical fiber is used to transmit the above-mentioned target light beam. By controlling the guide wire 13, the rear end of the laser catheter can be guided to a designated position in the blood vessel. The diameter of the ablation optical fiber is smaller than that of the guide wire 13 , and the ablation optical fiber, the guide wire 13 and the catheter cavity are non-coaxially arranged, that is, the ablation optical fiber and the guide wire 13 are eccentrically arranged in the catheter cavity.

[0061] Figure 5 is a schematic diagram of an ablation system in actual application. This fiber-coupled system is more effective than existing technologies. The laser catheter, that is, the connection port of the bundled output optical fiber 7, has a single large-core quartz optical fiber 4 with high structural strength and is not easily broken or damaged during use. The ultraviolet multimode optical fiber used ensures the stability of its working performance.

[0062] The benefits of the present invention are:

[0063] 1. The coupled UV laser ablation system through the fiber beam combiner is equipped with a light homogenizing component and a fiber beam combiner. When the laser passes through the microlens group, the microlens group performs beam flattening shaping on the laser. Subsequently, the split light spots are superimposed by the focusing lens to form a uniform energy distribution, thereby reducing the laser energy intensity received per unit area at the incident end of the large-core quartz optical fiber. By distributing the laser energy evenly and increasing the area for receiving the laser, damage to the end face of the incident end is avoided, thereby achieving the purpose of balanced energy application.

[0064] 2. The fiber-optic beam combiner effectively transmits homogenized laser energy from a single large-core quartz fiber to multiple small-core quartz fibers through fusion splicing, avoiding direct damage to the end face of the small-core quartz fiber incident end. It also simplifies the entire fiber coupling and laser energy transmission system, making it easy to achieve effective laser ablation of tissue.

[0065] 3. In the coupled ultraviolet laser ablation system after homogenization, the coupling efficiency of laser energy is improved, the requirement for the laser's excitation energy intensity can be reduced, and a smaller and lighter laser can be accommodated, making it more practical.

[0066] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0067] This document uses specific examples to illustrate the principles and implementations of the present invention. The above examples are only intended to help understand the system and core concepts of the present invention. At the same time, those skilled in the art will appreciate that variations in the specific implementations and scope of application are possible based on the concepts of the present invention. In summary, this specification should not be construed as limiting the present invention.

Claims

1. A fiber beam-coupled ultraviolet laser ablation system, characterized in that: The system comprises: a laser, a light homogenizing component and a fiber beam combining component; The laser is used to emit laser light; The light homogenizing component is arranged on the outgoing light path of the laser; the optical fiber beam combining component is arranged on the outgoing light path of the light homogenizing component; The light homogenization component is used to perform beam flattening and beam superposition on the laser to obtain a target light spot; The optical fiber beam combining assembly is used to perform multi-beam transmission on the target light spot.

2. The fiber beam combining coupled ultraviolet laser ablation system according to claim 1, characterized in that: The light homogenizing component includes: a diffraction optical component.

3. The fiber beam combining coupled ultraviolet laser ablation system according to claim 2, characterized in that: The diffractive optical component is a holographic diffuser.

4. The fiber beam combining and coupling ultraviolet laser ablation system according to claim 1, characterized in that: The light homogenization component comprises: A microlens group, arranged on the outgoing light path of the laser, for performing flat-top shaping on the laser beam to obtain a shaped beam; A focusing lens is arranged on the outgoing light path of the shaped light beam and is used for beam superposition of the shaped light beam to obtain the target light spot.

5. The fiber beam combining coupled ultraviolet laser ablation system according to claim 4, characterized in that: The focusing lens is a plano-convex lens or a bi-convex lens.

6. The fiber beam combining coupled ultraviolet laser ablation system according to claim 1, characterized in that: The optical fiber bundle combining assembly comprises: a large core diameter quartz optical fiber, a bundle input optical fiber, a tapered bundle combining optical fiber and a bundle output optical fiber; The large core diameter quartz optical fiber is arranged on the output optical path of the light homogenizing component; the large core diameter quartz optical fiber is connected to the tapered beam combining optical fiber via the bundle input optical fiber; the output end of the tapered beam combining optical fiber is connected to the bundle output optical fiber.

7. The optical fiber beam combining and coupling ultraviolet laser ablation system according to claim 6, characterized in that: The bundled input optical fiber includes a plurality of bundles of small-core quartz optical fibers.

8. The optical fiber beam combining and coupling ultraviolet laser ablation system according to claim 6, characterized in that: The core diameter of the large-core quartz optical fiber is greater than 600 μm.

9. The fiber beam combining and coupling ultraviolet laser ablation system according to claim 7, characterized in that: The core diameter of the small-core quartz optical fiber is less than 200 μm.

10. The fiber beam combining and coupling ultraviolet laser ablation system according to claim 6, characterized in that: The optical fiber bundle combining assembly comprises: a protective cover; The protective sleeve is coated on the surface of the large core diameter quartz optical fiber.

Images