Point ring laser output optical fiber

Abstract

The invention discloses a point ring laser output optical fiber, and relates to the technical field of laser, the point ring laser output optical fiber comprises a first optical fiber section and a second optical fiber section which are connected, the first optical fiber section comprises a refraction part, the refraction part is used for receiving parallel laser and refracting the parallel laser into the second optical fiber section, and the refraction part is used for receiving the parallel laser and refracting the parallel laser into the second optical fiber section. The second optical fiber section comprises a fiber core and at least one cladding structure wrapping the periphery of the fiber core, the cladding structure comprises a first cladding part and a second cladding part which are sequentially sleeved from inside to outside, and the refractive index of the first cladding part is smaller than that of the second cladding part. According to the technical scheme provided by the invention, at least one cladding structure is arranged at the periphery of the fiber core, and the cladding structure comprises two cladding parts with different refractive indexes, so that the refracted laser can be totally reflected in the cladding parts and is emitted from the cladding part with the high refractive index, and the refractive index of the laser can be greatly improved in a simple structure form. And the generation of the point annular light spot is realized.

Description

Technical Field

[0001] The invention relates to the technical field of optical fibers, and in particular to a point ring laser output optical fiber. Background Art

[0002] Dot ring laser is a special type of laser output, characterized by a light intensity distribution that presents a central bright area surrounded by one or more bright rings. This laser has unique optical properties and has important application value in many fields. For example, by introducing dot ring spot in the field of high-power laser processing, by preheating the material around the central working point, it can achieve technical advantages such as suppressing material splashing, preheating and slow cooling, and obtaining better processing efficiency and better processing quality.

[0003] At present, the technical approach to realize point ring laser in the market is mainly to obtain point ring laser by using an optical system including optical fiber, collimating lens, dot-shaped spot focusing lens, conical lens and ring-shaped spot focusing lens.

[0004] However, the optical elements used, such as the dot-shaped spot focusing lens, conical lens and annular spot focusing lens, are very complex to manufacture and expensive, and the single-lens focusing system of the center spot usually has large aberrations. Summary of the invention

[0005] The main purpose of the present invention is to provide a point ring laser output optical fiber, aiming to solve the current point ring laser processing process is complex and the manufacturing cost is high.

[0006] To achieve the above-mentioned purpose, the present invention proposes a point ring laser output optical fiber, comprising a first optical fiber segment and a second optical fiber segment connected to each other, wherein the first optical fiber segment comprises a refractive portion, wherein the refractive portion is used to receive parallel laser light and refract the parallel laser light into the second optical fiber segment, wherein the second optical fiber segment comprises a core and at least one cladding structure surrounding the core, wherein the cladding structure comprises a first cladding portion and a second cladding portion sequentially arranged from the inside to the outside, wherein the refractive index of the first cladding portion is less than the refractive index of the second cladding portion.

[0007] In one embodiment, a refractive index of the core is greater than a refractive index of the first cladding portion.

[0008] In one embodiment, the first optical fiber segment further includes a straight-through portion arranged corresponding to the fiber core, the straight-through portion is used for allowing parallel laser light to pass through and enter the fiber core, and the refractive portion surrounds the periphery of the straight-through portion.

[0009] In one embodiment, the refraction portion includes a first refraction block for receiving parallel laser and a second refraction block for outputting refracted laser, the first refraction block and the second refraction block are bonded to each other to form a bonding surface, and the outer edge of the bonding surface is set to converge inward in the direction of incidence of the parallel laser.

[0010] In one embodiment, a refractive index of the first refractive block is greater than a refractive index of the second refractive block.

[0011] In one embodiment, the first refraction block and the through portion are integrally provided.

[0012] In one embodiment, the first optical fiber segment is used to pass a Gaussian beam.

[0013] In one embodiment, the through portion and the fiber core are integrally provided.

[0014] In one embodiment, the first optical fiber segment and the second optical fiber segment are connected by fusion splicing.

[0015] In one embodiment, the material of the first cladding portion includes fluorine-doped quartz, and the material of the second cladding portion includes pure quartz.

[0016] The technical solution of the present invention is to set the first optical fiber segment, wherein the first optical fiber segment includes a refraction part for receiving parallel laser light and refracting the parallel laser light into the second optical fiber segment, so that the parallel laser light entering the first optical fiber segment is at least partially tilted to enter the second optical fiber segment, creating conditions for the total reflection of the subsequent laser light. By setting the second optical fiber segment, the second optical fiber segment includes a core and at least one cladding structure surrounding the outer periphery of the core, wherein the core is used to directly pass the laser light to form the center of the point annular light spot, and the cladding structure is composed of two cladding parts with different refractive indices, so that the laser light is finally reflected in the cladding part with a high refractive index, thereby forming the ring part of the point annular light spot, and one cladding structure corresponds to one ring part of the point annular light spot, thereby realizing the conversion of parallel laser light to point annular laser light through only one optical fiber. This solution reasonably sets the structure and materials inside the optical fiber, utilizes the total reflection principle and the refraction principle, and obtains the point annular light spot in a simple structure, reduces the manufacturing cost of the point annular light spot, and improves the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 the structures shown in these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the structure of an embodiment of a point ring laser output optical fiber provided by the present invention;

[0019] Figure 2 for Figure 1 Schematic diagram of the output spot of the midpoint ring laser output fiber.

[0020] Description of Figure Numbers:

[0021] 1000, point ring laser output optical fiber; 1, first optical fiber segment; 11, refraction part; 111, first refraction block; 112, second refraction block; 113, fitting surface; 12, straight-through part; 2, second optical fiber segment; 21, fiber core; 22, cladding structure; 221, first cladding part; 222, second cladding part.

[0022] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 work are within the scope of protection of the present invention.

[0024] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0025] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] Dot ring laser is a special type of laser output, characterized by a light intensity distribution that presents a central bright area surrounded by one or more bright rings. This laser has unique optical properties and has important application value in many fields. For example, by introducing dot ring spot in the field of high-power laser processing, by preheating the material around the central working point, it can achieve technical advantages such as suppressing material splashing, preheating and slow cooling, and obtaining better processing efficiency and better processing quality.

[0027] At present, the technical approach to realize the point ring light spot on the market is mainly to obtain the point ring light spot by using an optical system including an optical fiber, a collimating lens, a dot-shaped light spot focusing lens, a conical lens and a ring-shaped light spot focusing lens.

[0028] However, the optical elements used, such as the dot-shaped spot focusing lens, conical lens and annular spot focusing lens, are very complex to manufacture and expensive, and the single-lens focusing system of the center spot usually has large aberrations.

[0029] The main purpose of the present invention is to provide a point ring laser output optical fiber, aiming to solve the current point ring laser processing process is complex and the manufacturing cost is high.

[0030] See also Figure 1 The present invention proposes a point ring laser output optical fiber 1000, comprising a first optical fiber segment 1 and a second optical fiber segment 2 connected to each other, wherein the first optical fiber segment 1 comprises a refractive portion 11, wherein the refractive portion 11 is used to receive parallel laser light and refract the parallel laser light into the second optical fiber segment 2, wherein the second optical fiber segment 2 comprises a core 21 and at least one cladding structure 22 surrounding the core 21, wherein the cladding structure 22 comprises a first cladding portion 221 and a second cladding portion 222 sequentially arranged from the inside to the outside, wherein the refractive index of the first cladding portion 221 is less than the refractive index of the second cladding portion 222.

[0031] The technical solution of the present invention is to set the first optical fiber segment 1, wherein the first optical fiber segment 1 includes a refraction portion 11 for receiving parallel laser light and refracting the parallel laser light into the second optical fiber segment 2, so that the parallel laser light entering the first optical fiber segment 1 is at least partially obliquely injected into the second optical fiber segment 2, creating conditions for the subsequent total reflection of the laser light. By setting the second optical fiber segment 2, the second optical fiber segment 2 includes a core 21 and at least one cladding structure 22 surrounding the outer periphery of the core 21, wherein the core 21 is used to directly pass the laser light to form the center of the point annular light spot, and the cladding structure 22 is composed of two cladding parts with different refractive indices, so that the laser light is finally reflected in the cladding part with a high refractive index, thereby forming the ring part of the point annular light spot, and one cladding structure 22 corresponds to one ring part of the point annular light spot, thereby realizing the conversion of parallel laser light to point annular laser light through only one optical fiber. This solution reasonably sets the structure and materials inside the optical fiber, utilizes the total reflection principle and the refraction principle, and obtains the point annular light spot in a simple structure, reduces the manufacturing cost of the point annular light spot, and improves the production efficiency.

[0032] It should be noted that the function of the refraction portion 11 is to refract at least part of the parallel laser light so that it forms an angle with respect to the axis of the optical fiber, thereby ensuring that the light in the cladding structure 22 is totally reflected in the second cladding portion 222 during the subsequent propagation process. It should also be noted that the second optical fiber segment 2 has a sufficiently long length so that when the light refracted by the refraction portion 11 enters the second optical fiber segment 2, it can ensure that the light has a sufficient travel distance to enter the second cladding portion 222, and the incident angle is greater than or equal to the critical angle, thereby satisfying the condition of total reflection.

[0033] The technical solution provided by the present invention does not limit the number of the cladding structure 22. In a preferred embodiment of the present invention, please refer to Figure 1 The cladding structure 22 is set as one. Such a setting can better control the light intensity at the light ring in the point ring light spot and improve the laser output quality of the optical fiber.

[0034] It is worth mentioning that, in one embodiment, the material of the first cladding portion 221 is set to fluorine-doped quartz, and the material of the second cladding portion 222 is set to pure quartz. Among them, fluorine-doped quartz can reduce the refractive index of quartz glass, thereby ensuring that the refractive index of the second cladding portion 222 is greater than the refractive index of the first cladding portion 221, so as to ensure that the optical signal is mainly propagated in the material with a high refractive index, while reducing the loss, and fluorine-doped quartz also has good chemical inertness, is not easily affected by the surrounding environment, and has high thermal stability, and can maintain the optical properties unchanged in a high temperature environment.

[0035] Furthermore, in order to ensure the brightness of the dot annular light spot in the center, the refractive index of the core 21 is greater than the refractive index of the first cladding portion 221. In this way, the core 21 transmits not only the parallel laser light directly injected from the first optical fiber segment 1, but also the partially refracted laser light, so that the laser light in the optical fiber is completely distributed in the core 21 and the second cladding portion 222, further improving the laser output quality of the optical fiber.

[0036] In order to construct the central part of the point ring light spot, in one embodiment, the first optical fiber segment 1 also includes a straight-through portion 12 arranged corresponding to the fiber core 21, and the straight-through portion 12 is used for parallel laser light to pass through and be injected into the fiber core 21, and the refractive portion 11 surrounds the periphery of the straight-through portion 12. In this way, the parallel laser light can be directly injected into the fiber core 21 through the straight-through portion 12, so as to better control the light intensity of the central part of the point ring light spot. It is worth mentioning that the shape of the straight-through portion 12 and the fiber core 21 are both set to be cylindrical, and the diameter is the same. In the first optical fiber segment 1, the parts except the straight-through portion 12 are all set to be the refractive portion 11, so as to ensure that all laser light except that injected into the fiber core 21 can pass through the refractive portion 11.

[0037] Furthermore, the refraction part 11 includes a first refraction block 111 for receiving parallel laser light and a second refraction block 112 for outputting refracted laser light, and the first refraction block 111 and the second refraction block 112 are bonded to each other to form a bonding surface 113, and the outer edge of the bonding surface 113 is arranged to converge inwards in the direction of the parallel laser light incident. With such arrangement, after the parallel laser light part passing through the first refraction block 111 is reflected by the bonding surface 113, since the outer edge of the bonding surface 113 is arranged to converge inwards in the direction of the parallel laser light incident, the reflection direction of the reflected light is always toward the direction close to the axis, thereby preventing the reflected light from being directly incident on the outermost layer of the optical fiber, and reducing the loss during the laser propagation process.

[0038] Furthermore, the refractive index of the first refraction block 111 is greater than the refractive index of the second refraction block 112. With such a configuration, after the parallel laser light portion passing through the first refraction block 111 is refracted by the bonding surface 113, since the refractive index of the first refraction block 111 is greater than the refractive index of the second refraction block 112, the refraction direction of the refracted light is always toward the direction close to the axis, thereby preventing the refracted light from being directly projected toward the outermost layer of the optical fiber, thereby reducing the loss during laser propagation.

[0039] In an embodiment provided by the present invention, the first refraction block 111 is set in a conical shape, and the first refraction block 111 is set in an integral manner with the straight-through portion 12, and the whole is set in a truncated cone shape. Among them, the inclined surface of the truncated cone is the fitting surface 113, which is used to refract the parallel laser, and the two surfaces of the truncated cone in the laser injection direction are respectively used to receive the parallel laser and output the parallel laser to the fiber core 21, and the side with a smaller area corresponds to the cross section of the fiber core 21. Such a setting is more reasonable in structure, more stable, and the overall structure of the optical fiber is more compact.

[0040] It should be noted that the present solution does not limit the specific structure of the first optical fiber segment 1. In another embodiment, the first optical fiber segment 1 is configured as a lens with positive optical focal length. With this configuration, part of the laser light in the central area can be directly emitted into the fiber core 21, and the remaining part of the laser light is refracted and focused by the lens, thereby realizing the refraction and direct passage of parallel laser light in a simple structural form.

[0041] In order to further increase the compactness of the point ring laser output optical fiber 1000, the straight-through portion 12 is integrated with the fiber core 21. This can better facilitate the parallel laser in the middle area to directly enter the fiber core 21, and the connection between the first fiber segment 1 and the second fiber segment 2 can be tighter. It is worth mentioning that in a specific embodiment, the first refraction block 111, the straight-through portion 12 and the fiber core 21 are all integrated and made of high refractive index materials. Such an arrangement not only realizes the basic functional requirements of the optical fiber, but also makes the structure more stable and convenient for assembly.

[0042] Furthermore, the first optical fiber segment 1 is used to pass a Gaussian beam, wherein the light intensity of the Gaussian beam follows a two-dimensional Gaussian function, the light intensity of the Gaussian beam reaches a maximum value at the central axis, and decays as the distance from the central axis increases. The Gaussian beam has good stability and predictability, and is convenient for designing an optical path according to the light intensity distribution of the desired light spot. In this embodiment, the light intensity of different areas of the point annular light spot is adjusted by changing the taper of the first refraction block 111.

[0043] In one embodiment of the present invention, the first optical fiber segment 1 and the second optical fiber segment 2 are connected by fusion splicing. Fiber fusion splicing refers to the process of melting and fusing the end faces of two optical fiber segments by high temperature heating to form a continuous and almost lossless optical channel. It is worth mentioning that the first optical fiber segment 1 and the second optical fiber segment 2 in the optical fiber are actually integrated, and the two optical fiber segments are connected by fusion splicing, which can improve the stability of the entire optical fiber structure and reduce the loss during laser propagation.

[0044] It should be noted that Figure 2Schematic diagram of the output light spot of the point ring laser output fiber 1000 in this embodiment. The gray area is the main light emitting area, and it can be seen that the light intensity distribution of the point ring light spot is relatively standard, with high imaging quality, meeting the basic requirements.

[0045] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A point ring laser output optical fiber, characterized in that: The optical fiber comprises a first optical fiber segment and a second optical fiber segment connected to each other, wherein the first optical fiber segment comprises a refractive portion, wherein the refractive portion is used to receive parallel laser light and refract the parallel laser light into the second optical fiber segment, wherein the second optical fiber segment comprises a core and at least one cladding structure surrounding the core, wherein the cladding structure comprises a first cladding portion and a second cladding portion sequentially arranged from the inside to the outside, wherein the refractive index of the first cladding portion is less than the refractive index of the second cladding portion.

2. The point ring laser output optical fiber according to claim 1, characterized in that: The refractive index of the core is greater than the refractive index of the first cladding portion.

3. The point ring laser output optical fiber according to claim 1, characterized in that: The first optical fiber segment further includes a straight-through portion arranged corresponding to the fiber core, the straight-through portion is used for allowing parallel laser light to pass through and enter the fiber core, and the refractive portion surrounds the periphery of the straight-through portion.

4. The point ring laser output optical fiber according to claim 3, characterized in that: The refraction part includes a first refraction block for receiving parallel laser light and a second refraction block for outputting refracted laser light. The first refraction block and the second refraction block are bonded to each other to form a bonding surface. The outer edge of the bonding surface is convergent inwardly in the incident direction of the parallel laser light.

5. The point ring laser output optical fiber according to claim 4, characterized in that: A refractive index of the first refractive block is greater than a refractive index of the second refractive block.

6. The point ring laser output optical fiber according to claim 4, characterized in that: The first refraction block is integrally provided with the straight-through portion.

7. The point ring laser output optical fiber according to claim 4, characterized in that: The first optical fiber segment is used for passing a Gaussian beam.

8. The point ring laser output optical fiber according to claim 3, characterized in that: The through portion and the fiber core are integrally arranged.

9. The point ring laser output optical fiber according to claim 1, characterized in that: The first optical fiber segment is connected to the second optical fiber segment by fusion splicing.

10. The point ring laser output optical fiber according to claim 1, characterized in that: The material of the first cladding portion includes fluorine-doped quartz, and the material of the second cladding portion includes pure quartz.

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