Laser output optical device, laser and apparatus, method

Abstract

The invention discloses a laser output optical device, a laser, equipment and a method. The laser output optical device comprises an output optical fiber, an optical waveguide and an optical output head which are connected in sequence, the output optical fiber is used for outputting point ring light beams, a cladding layer, wrapping the second fiber core, of at least partial area, close to the output optical fiber, of the optical waveguide comprises a second conical structure, and the cross section of the second conical structure is annular. The outer diameter of the second conical structure is gradually increased in the light beam transmission direction, and the second conical structure is used for adjusting the light path of the point ring light beam so as to adjust the divergence angle of inner and outer ring light beams. And the optical output head is used for outputting the light beam adjusted by the optical waveguide. The pre-modulated light from the output optical fiber is accurately regulated and controlled, the divergence angle of the output light is adjusted, the light beam quality is improved, and meanwhile the device has the advantages of being simple in structure, low in cost and high in stability.

Description

Technical Field

[0001] This invention relates to the field of optical laser technology, and in particular to a laser output optical device, laser and equipment, and method. Background Technology

[0002] Fiber lasers have become the mainstream lasers, with advantages such as excellent beam quality, extremely high electro-optical conversion efficiency, excellent heat dissipation and reliability, compact structure, high stability, strong power scalability, and green environmental friendliness.

[0003] Therefore, fiber lasers are widely used in industrial processing (such as laser cutting, drilling, and welding), shipbuilding, new energy, and defense. However, controlling the output beam divergence angle of fiber lasers remains a key technical challenge in these applications. The instability of the output beam divergence angle directly affects processing accuracy and efficiency. For example, in sheet metal cutting, changes in the divergence angle can lead to uneven kerf width or inconsistent drilling depth.

[0004] Currently, the control of the divergence angle of high-power fiber laser output light mainly relies on two mainstream technical solutions: collimation focusing systems and variable-magnification beam expanding systems. Collimation focusing systems integrate optical lens groups inside the laser optical output head, and by adjusting the focal point position, they "equivalently" change the spot size over the working distance, thereby indirectly controlling the divergence angle. Variable-magnification beam expanding systems, on the other hand, directly reduce the divergence angle by increasing the output beam diameter, or increase the divergence angle through manipulation, to adapt to different application requirements. These systems are based on geometric optics principles and achieve beam shaping through complex optical path designs. Summary of the Invention

[0005] Based on this, it is necessary to propose an optical waveguide, laser output optical device, laser and equipment, and method to address the above problems.

[0006] A laser output optical device, comprising: connected in sequence: The output optical fiber includes at least one first fiber core and a cladding covering the first fiber core radially outward, for outputting a point ring beam; An optical waveguide includes at least one second fiber core and a cladding covering the second fiber core radially outward. The cladding covering the second fiber core in at least a portion of the region near the output optical fiber includes a second tapered structure. The cross-section of the second tapered structure is annular, and the outer diameter of the second tapered structure gradually increases along the beam transmission direction. This is used to adjust the optical path of the point-ring beam to adjust the divergence angle of the inner and outer ring beams. An optical output head is used to output the light beam adjusted by the optical waveguide.

[0007] Preferably, the cladding covering the first fiber core in at least a portion of the output optical fiber near the optical waveguide includes a first tapered structure, the first tapered structure being used to control the size of the divergence angle of the output beam from the output optical fiber.

[0008] Preferably, the cladding covering the first fiber core includes a first cladding, and the first cladding near at least a portion of the optical waveguide includes a first tapered structure; Alternatively, the cladding covering the first fiber core may include a first cladding and a second cladding, wherein the second cladding near at least a portion of the optical waveguide may include a first tapered structure; Alternatively, the cladding covering the first fiber core may include a first cladding, a second cladding, and an outer cladding, wherein the outer cladding near at least a portion of the optical waveguide may include a first tapered structure.

[0009] Preferably, the cladding covering the second fiber core includes a fifth cladding, and the fifth cladding near at least a portion of the output fiber includes a second tapered structure; Alternatively, the cladding covering the second fiber core may include a fifth cladding and a sixth cladding, wherein the sixth cladding near at least a portion of the output fiber may include a second tapered structure; Alternatively, the cladding covering the second fiber core may include a fifth cladding, a sixth cladding, and an outer cladding, wherein the outer cladding near at least a portion of the output fiber may include a second tapered structure.

[0010] Preferably, at least a portion of the cladding covering the second fiber core near the optical output head includes a third conical structure, which is used to control the divergence angle of the output beam from the optical waveguide.

[0011] Preferably, the cladding covering the second fiber core includes a fifth cladding, and the fifth cladding near at least a portion of the optical output head includes a third conical structure; Alternatively, the cladding covering the second fiber core may include a fifth cladding and a sixth cladding, wherein the sixth cladding near at least a portion of the optical output head includes a third conical structure; Alternatively, the cladding covering the first fiber core may include a fifth cladding, a sixth cladding, and an outer cladding, wherein the outer cladding near at least a portion of the optical output head includes a third conical structure.

[0012] Preferably, the diameter of the first fiber core is less than or equal to the diameter of the second fiber core.

[0013] A method for fabricating a laser output optical device, characterized in that the method comprises: An output optical fiber is provided, including at least one first fiber core and a first multi-cladding assembly that radially and outwardly covers the first fiber core, for outputting a point-ring beam; An optical waveguide is provided, and one end of the optical waveguide is tapered to obtain a second tapered structure; An optical output head is provided for outputting a beam of light adjusted by the optical waveguide; The output end of the output optical fiber is connected to the second tapered end of the optical waveguide, and the other end of the optical waveguide is connected to the optical output head.

[0014] A laser, comprising the aforementioned laser output optics.

[0015] A laser processing device, comprising the laser described above.

[0016] The embodiments of this application have the following beneficial effects: This application utilizes an optical waveguide to precisely control the pre-modulated light from the output optical fiber, achieving a smooth transition of the optical mode field, significantly reducing coupling loss, improving optical transmission efficiency, and enabling adjustment of the output light divergence angle and improvement of beam quality. Furthermore, this application features a simple structure requiring no additional optical components, enhanced stability, simplified manufacturing process, and standardization, making it suitable for mass production and significantly reducing unit manufacturing costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] in: Figure 1 This is a schematic diagram of the output optical fiber in one embodiment; Figure 2 This is a schematic diagram of the output optical fiber in another embodiment; Figure 3 This is a schematic diagram of the optical waveguide structure in one embodiment; Figure 4 This is a cross-sectional view of the optical waveguide in another embodiment; Figure 5 This is a cross-sectional view of an optical waveguide in one embodiment; Figure 6 This is a schematic diagram of the structure of a laser output optical device in one embodiment; Figure 7 This is a schematic diagram of the structure of the laser output optics in another embodiment; Figure 8 This is a schematic diagram of the original, unmodulated laser spot on the output fiber in one embodiment; Figure 9 This is a schematic diagram of a dotted ring light spot output by an output fiber with a special refractive index design in one embodiment. Detailed Implementation The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] This application provides a laser output optical device, such as... Figure 6 and Figure 7 As shown, it includes an output optical fiber 1, an optical waveguide 2, and an optical output head 3 connected in sequence; The output optical fiber 1 includes at least one first fiber core 101 and a cladding 102 that covers the first fiber core radially outward, for outputting a dot ring beam. The optical waveguide 2 includes at least one second fiber core 201 and a cladding 202 that radially surrounds the second fiber core. At least a portion of the cladding 202 near the output fiber 1 includes a second tapered structure V2. The cross-section of the second tapered structure V2 is annular, and the outer diameter of the second tapered structure V2 gradually increases along the beam propagation direction, used to adjust the optical path of the point-ring beam to adjust the divergence angle of the inner and outer ring beams. An optical output head 3 is used to output the beam adjusted by the optical waveguide. The annular shape can be circular, elliptical, triangular, rectangular, or racetrack-shaped, etc., and can be designed according to the actual fiber structure during implementation.

[0020] This application modulates the output point ring light of the output fiber through an optical waveguide, thereby expanding or shrinking the divergence angle of the outer ring beam. Finally, the optical output head 3 completes the final beam shaping and output, realizing dual adjustment of the output beam. This allows the device to maintain high beam quality while greatly simplifying traditional complex optical systems and avoiding problems such as high cost, complex structure, and aberration risks associated with using multiple lens groups or variable magnification beam expanders.

[0021] In some embodiments, the cladding 102 covering at least a portion of the first fiber core of the output fiber 1 near the optical waveguide 2 includes a first tapered structure V1. The cross-section of the first tapered structure V1 is annular, and the outer diameter of the first tapered structure V1 gradually decreases along the beam transmission direction.

[0022] It is understood that at least a portion of the cladding 102 covering the first fiber core includes a first conical structure. This conical structure can pre-compress the outer ring light in the transmitted light, effectively reducing its divergence angle, so that the optical signal is initially shaped before entering the subsequent optical modulation element, reducing the complexity of the subsequent modulation stage. At the same time, the conical structure promotes the smooth transition of the optical mode field, reduces mode mismatch when fused with the subsequent optical modulation element, thereby controlling the coupling loss at a low level and improving the optical transmission efficiency.

[0023] In this embodiment, the tapered structure of the output fiber 1 first pre-compresses and initially shapes the laser beam, effectively reducing the divergence angle of the outer ring light; the tapered end of the optical waveguide 2 then performs precise secondary control on the pre-modulated light, further adjusting the divergence angle through its tapered structure; finally, the optical output head 3 completes the final shaping and output of the beam, realizing triple adjustment of the output beam. This allows the device to maintain high beam quality while significantly simplifying traditional complex optical systems, avoiding the problems of high cost, complex structure, and aberration risks associated with using multiple lens groups or variable magnification beam expanders.

[0024] In some embodiments, the cladding 102 covering the first fiber core comprises a cladding layer sequentially covering the fiber in a radially outward direction. The output optical fiber 1 includes a first fiber core 101 and a first cladding 1021.

[0025] Understandably, the first core 101 of the output fiber 1 adopts a special refractive index design, which can realize the output of the point ring beam through the core alone.

[0026] In some embodiments, the cladding 102 covering the first fiber core includes at least two cladding layers that are sequentially covered radially outward.

[0027] For example, the cladding 102 covering the first fiber core includes a first cladding 1021 and a second cladding 1022 that are sequentially covered radially outward.

[0028] The first cladding 1021 directly covers the outside of the first fiber core 101, with an inner diameter of 34μm and an outer diameter of 48μm. Its main function is to form a transmission waveguide for the fundamental mode light (such as wavelength λ1) together with the first fiber core 101, ensuring low-loss transmission of the inner ring light.

[0029] The second cladding 1022 is located outside the first cladding 1021, with an inner diameter of 48 μm and an outer diameter of 102 μm. The second cladding 1022 is used to transmit the outer ring beam.

[0030] Furthermore, the cladding 102 covering the first fiber core includes a first cladding 1021, a second cladding 1022, and a third cladding 1023 that are sequentially covered radially outward.

[0031] The first cladding 1021 directly covers the outside of the first fiber core 101, with an inner diameter of 34μm and an outer diameter of 48μm. Its main function is to form a transmission waveguide for the fundamental mode light (such as wavelength λ1) together with the first fiber core 101, ensuring low-loss transmission of the inner ring light.

[0032] The second cladding 1022 is located outside the first cladding 1021, with an inner diameter of 48 μm and an outer diameter of 102 μm. The second cladding 1022 is used to transmit the outer ring beam.

[0033] The third cladding layer 1023, as a key functional layer, has an inner diameter of 102 μm and an outer diameter of 120 μm. Its structure can be selectively modulated during the tapered processing. When one end of the third cladding layer 1023 has a tapered structure, it has a pre-compression effect on the inner and outer ring light, initially reducing the divergence angle.

[0034] Furthermore, the cladding 102 covering the first fiber core includes a first cladding 1021, a second cladding 1022, a third cladding 1023, and a fourth cladding 1024 that are sequentially covered radially outward.

[0035] The fourth cladding 1024 is located on the outermost layer, with an inner diameter of 120 μm and an outer diameter of 360 μm. When one end of the fourth cladding 1024 has a conical structure, it has a pre-compression effect on the inner and outer ring light, initially reducing the divergence angle. It achieves pre-shaping of the light field through geometric deformation, laying the foundation for subsequent modulation by optical modulation elements.

[0036] Furthermore, the fourth cladding layer 1024 is also covered with a first coating layer 1025, which acts as a physical barrier.

[0037] The first coating layer 1025 is typically made of polymer materials (such as acrylate or polyimide) and is directly coated on the outside of the fourth cladding layer 1024, effectively preventing microcracks and breaks in the optical fiber during bending, stretching, or installation. Simultaneously, the first coating layer 1025 isolates the optical fiber from external moisture, chemical corrosion, and dust, preventing these factors from damaging the inner cladding and the first fiber core 101, thus ensuring the long-term reliability of the optical fiber in harsh industrial environments.

[0038] For example, the first coating layer 1025 has a thickness of 650µm, providing sufficient protective barrier for the optical fiber.

[0039] In some embodiments, the cladding 102 covering at least a portion of the first fiber core of the output fiber 1 near the optical waveguide 2 includes a first tapered structure V1. The cross-section of the first tapered structure V1 is annular, and the outer diameter of the first tapered structure gradually decreases along the optical path direction.

[0040] For example, the output optical fiber 1 includes a first core 101 and a first cladding 1021. At least a portion of the first cladding 1021 near the optical waveguide 2 includes a first tapered structure V1.

[0041] Understandably, the first core 101 of the output fiber employs a special refractive index design, enabling the output of a point-ring beam solely through the core. The tapered structure at one end of the first cladding 1021 provides pre-compression of the outer ring light, initially reducing the divergence angle and effectively improving the quality of the point-ring output light.

[0042] For example, the output optical fiber 1 includes a first core 101, a first cladding 1021, and a second cladding 1022. At least a portion of the second cladding 1022 near the optical waveguide 2 includes a first tapered structure V1.

[0043] For example, the output optical fiber 1 includes a first core 101, a first cladding 1021, a second cladding 1022, and a third cladding 1023. At least a portion of the third cladding 1023 near the optical waveguide 2 includes a first tapered structure V1.

[0044] For example, the output optical fiber 1 includes a first core 101, a first cladding 1021, a second cladding 1022, a third cladding 1023, and a fourth cladding 1024. At least a portion of the fourth cladding 1024 near the optical waveguide 2 includes a first tapered structure V1.

[0045] The conical structure is made by laser processing, mechanical grinding, lapping, chemical etching, polishing or drawing processes.

[0046] With this design, the tapered structure of the outermost cladding of the output fiber can pre-compress the outer ring light divergence angle and reduce the splicing loss with subsequent optical modulation elements through mode matching, effectively improving the quality of the point ring output light.

[0047] In some embodiments, when two or more first fiber cores 101 are provided, the wavelengths of each first fiber core 101 may be the same or different.

[0048] When there are two or more first fiber cores 101, they can be distributed in different geometric arrangements in the cross-section of the optical fiber. The introduction of multiple first fiber cores 101 significantly improves the transmission capacity and functional integration of the optical fiber.

[0049] Geometric arrangement methods specifically include: Symmetrical arrangement: Multiple first fiber cores 101 (such as 2 or 4) are symmetrically distributed at the center of the fiber cross-section, with equal spacing between each fiber core. This arrangement is beneficial for maintaining optical field symmetry and mode stability.

[0050] Circular arrangement: The first fiber core 101 is arranged at equal intervals along the circumference, and an additional fiber core may or may not be set in the center, which is particularly suitable for vortex optical transmission and mode control.

[0051] In some embodiments, such as Figure 3 As shown, the optical waveguide 2 includes at least one second fiber core 201 and a cladding 202 that covers the second fiber core radially outward; at least a portion of the cladding 202 covering the second fiber core near the output optical fiber 1 includes a second tapered structure V2, the cross-section of the second tapered structure V2 is annular, and the outer diameter of the second tapered structure V2 gradually increases along the beam transmission direction.

[0052] This application uses a tapered structure to precisely control the pre-modulated light from the output fiber 1, thereby compressing the divergence angle of the output light and improving the beam quality.

[0053] In some embodiments, the cladding 202 covering the second fiber core comprises a cladding layer that is sequentially clad outward in a radial direction. The optical waveguide 2 includes a second fiber core 201 and a fifth cladding 2021. At least a portion of the fifth cladding 2021 near the output fiber 1 includes a second tapered structure V2.

[0054] Understandably, the second fiber core 201 of the optical waveguide 2 employs a special refractive index design, enabling the output of a point-ring beam solely through the fiber core. At least a portion of the fifth cladding 2021 is tapered, resulting in a tapered structure that allows adjustment of the outer ring beam divergence angle and thus the output point-ring beam.

[0055] In some embodiments, the cladding 202 covering the second fiber core includes a fifth cladding 2021 and a sixth cladding 2022. The sixth cladding 2022 includes a second tapered structure V2 in at least a portion of its region near the output fiber 1. The second fiber core 201 of the optical waveguide 2 is used to transmit the inner ring beam, and the sixth cladding 2022 is used to transmit the outer ring beam.

[0056] In some embodiments, the cladding 202 covering the second fiber core includes at least two cladding layers that are sequentially covered radially outward.

[0057] The cladding 202 covering the second fiber core includes a fifth cladding 2021, a sixth cladding 2022, and a seventh cladding 202 that are sequentially covered radially outward.

[0058] The fifth cladding 2021 directly covers the outside of the second fiber core 201, with an inner diameter of 34μm and an outer diameter of 50μm, and together with the second fiber core 201 forms the fundamental mode optical transmission channel; The sixth cladding layer 2022 is located outside the fifth cladding layer 2021, with an inner diameter of 50 μm and an outer diameter of 120 μm, and is used to transmit outer ring light; The seventh cladding layer 2023 has an inner diameter of 120 μm and an outer diameter of 150 μm, and participates in the modulation of the outer ring light in the conical structure; Furthermore, the cladding 202 covering the second fiber core includes a fifth cladding 2021, a sixth cladding 2022, a seventh cladding 2023, and an eighth cladding 2024 that are sequentially covered radially outward.

[0059] The fifth cladding 2021 directly covers the outside of the second fiber core 201, with an inner diameter of 34μm and an outer diameter of 50μm, and together with the second fiber core 201 forms the fundamental mode optical transmission channel; The sixth cladding layer 2022 is located outside the fifth cladding layer 2021, with an inner diameter of 50 μm and an outer diameter of 120 μm, and is used to transmit outer ring light; The seventh cladding layer 2023 has an inner diameter of 120 μm and an outer diameter of 150 μm, and participates in the modulation of the outer ring light in the conical structure; The eighth cladding layer, located on the outermost layer, has an inner diameter of 150 μm and an outer diameter of 420 μm, and is the main load-bearing layer of the conical structure.

[0060] In some embodiments, the tapered structure may be implemented in the following ways: Method 1: The outer diameter of at least a portion of the seventh cladding 2023 is gradually distributed along the beam propagation direction (e.g., the outer diameter gradually decreases or increases), focusing on modulating the intermediate mode light. The light field is limited or guided by changing the geometry of the intermediate layer, which is suitable for scenarios that require fine control of the intermediate mode light field.

[0061] Method 2: The outer diameter of at least a portion of the eighth cladding is gradually distributed along the beam propagation direction. As the main carrier layer for the outer diameter change, its geometric deformation directly affects the outer ring light (higher-order mode). Changing the boundary conditions of the outer cladding is the key to achieving divergence angle compression.

[0062] Method 3: The outer diameters of at least a portion of the seventh cladding layer 2023 and the eighth cladding layer are distributed in a coordinated, gradual manner along the beam propagation direction. The seventh cladding layer 2023 and the eighth cladding layer undergo synchronous geometric deformation (e.g., simultaneously expanding outward or contracting inward), which enables efficient control of both intermediate and higher-order modes, achieving optimal beam shaping.

[0063] In some embodiments, the purpose of the tapered end is to adjust the beam divergence angle, specifically to compress or expand the divergence angle. The processing methods include the following embodiments: like Figure 3As shown, at least a portion of the input end of the optical waveguide 2 (i.e., the end closest to the output fiber 1) is tapered. In this embodiment, the tapered end (i.e., the second tapered structure) has a structure where the outer diameter gradually increases along the beam transmission direction (i.e., an outward expansion structure). Specifically, the cladding diameter of the input end face of the optical waveguide 2 is designed to match the output end diameter of the output fiber 1, and then gradually increases along the axial outer diameter to the normal outer diameter of the optical waveguide. The structure of small-end inlet and large-end outlet increases the effective numerical aperture and reception angle of the optical waveguide 2, enabling it to receive the outer ring light (higher-order modes) from the output fiber 1 more fully, significantly reducing the coupling loss at the fusion splice; at the same time, the divergence angle of the outer ring light is compressed using the principle of refraction.

[0064] like Figure 4 As shown, at least a portion of the output end of the optical waveguide 2 (i.e., the end closest to the optical output head 3) is tapered. In this embodiment, the tapered end (i.e., the third tapered structure) has a structure in which the outer diameter gradually decreases along the beam transmission direction (i.e., an inwardly contracting structure). By reducing the outer diameter of the cladding at the end of the optical waveguide 2, the transmitted beam is physically confined and shaped twice, which can further compress the divergence angle of the output light and effectively cut off residual higher-order modes, ensuring that the beam entering the optical output head 3 has higher fundamental mode purity.

[0065] Understandably, at least a portion of the input and output regions of the optical waveguide 2 are tapered. The input region adopts a structure with a gradually increasing outer diameter to ensure efficient coupling of the stored light and initial divergence angle compression. The output region adopts a structure with a gradually decreasing outer diameter to achieve final beam purification and shaping. The phased geometric size changes, from small to large and then back to small, allow the optical mode field to undergo a complete evolution process of smooth expansion, stable transmission, and precise convergence, enabling more precise divergence angle control and optimal beam quality.

[0066] The overall cladding of the optical waveguide 2 (such as the seventh cladding 2023 and the eighth cladding) can also be tapered. When the tapering reduces the confinement effect of the cladding on the beam, it can be used to expand the beam divergence angle to meet the needs of specific application scenarios.

[0067] Furthermore, the eighth cladding layer is also covered with a second coating layer 2024, which acts as a physical barrier.

[0068] The second coating layer 2024 is typically made of polymer materials (such as acrylate or polyimide) and is directly coated on the outside of the eighth cladding layer. This effectively prevents microcracks and breaks in the optical fiber during bending, stretching, or installation. Simultaneously, the second coating layer 2024 isolates the fiber from external moisture, chemical corrosion, and dust, preventing these factors from damaging the inner cladding and the second fiber core 201, thus ensuring the long-term reliability of the optical fiber in harsh industrial environments.

[0069] For example, the second coating layer 2024 has a thickness of 650µm, providing sufficient protective barrier for the optical fiber.

[0070] In some embodiments, the two outermost cladding layers have a tapered structure at the end closest to the output fiber to modulate the beam and adjust the divergence angle; while the other end can be selected for additional processing according to actual needs, mainly affecting the quality and mode control of the output beam.

[0071] For example, one end of the seventh cladding layer 2023 and the eighth cladding layer has a tapered structure.

[0072] The seventh cladding 2023 and the eighth cladding have an outwardly expanding conical structure, while the outer diameters of the second core 201, the fifth cladding 2021 and the sixth cladding 2022 remain unchanged.

[0073] The tapered structure of the outermost two cladding layers (i.e., the seventh cladding layer 2023 and the eighth cladding layer) of optical waveguide 2 achieves key optical functions through a synergistic physical mechanism. This tapered structure first induces an optical field spreading effect: when the outer ring light (higher-order modes) propagates to the tapered interface, its propagation path is deflected outwards due to refraction, effectively compressing the divergence angle of the output light. Simultaneously, the tapered structure optimizes mode matching, promotes a smooth transition of the optical field between the optical waveguide and the output fiber 1, reduces interface reflection loss, and improves transmission efficiency.

[0074] In addition, the tapered shape has a cutoff effect on higher-order modes, suppressing unnecessary mode transmission and further improving beam quality. This allows the optical waveguide to precisely control the laser output characteristics, providing stable and efficient optical performance for the device.

[0075] The conical structure is made by laser processing, mechanical grinding, lapping, chemical etching, polishing or drawing processes.

[0076] Geometric arrangement methods specifically include: Symmetrical arrangement: Multiple second fiber cores 201 (such as 2 or 4) are symmetrically distributed at the center of the fiber cross-section, with equal spacing between each fiber core. This arrangement is beneficial for maintaining optical field symmetry and mode stability.

[0077] Ring-shaped arrangement: The second fiber core 201 is arranged at equal intervals along the circumference, and an additional fiber core may or may not be set in the center, which is particularly suitable for vortex optical transmission and mode control.

[0078] In some embodiments, the optical waveguide 2 cooperates with the output optical fiber 1, which includes a first fiber core 101 and a first cladding 1021 radially outwardly covering the fiber. The first fiber core 101 employs a special refractive index distribution design (e.g., a parabolic refractive index distribution or a multi-step refractive index distribution), enabling the laser to form a unique point ring light with a distinctive energy distribution during propagation within the fiber core, thus eliminating the need for a multi-layer cladding structure to separately transmit the inner and outer ring light. One end of the first cladding 1021 surrounding the output optical fiber 1 has a tapered structure.

[0079] Optical waveguide 2 can also adopt the same simplified structural design, namely, including a second fiber core 201 and a fifth cladding 2021 that clad the fiber radially outward. To achieve optimal beam coupling and shaping, the fifth cladding 2021 of optical waveguide 2 has a tapered structure at both ends (i.e., the input end and the output end). The beam is controlled by the gradual change in the outer diameter. At the input end of optical waveguide 2 (the end closer to the output fiber 1), the outer diameter of the cladding gradually increases along the beam propagation direction (i.e., it exhibits an outward expansion structure), increasing the receiving aperture of the optical waveguide and enabling efficient coupling of the point ring light from the output fiber 1, reducing interface reflection loss. At the output end of optical waveguide 2 (the end closer to the optical output head), the outer diameter of the cladding gradually decreases along the beam propagation direction (i.e., it exhibits an inward contraction structure). By reducing the cladding aperture at the output end, the divergence angle of the output beam is further compressed, and stray higher-order modes are filtered out, ensuring that the final output point ring light has extremely high beam quality. While maintaining the point-loop optical output characteristics, it significantly simplifies the cladding structure of optical fibers and waveguides, and reduces the complexity of drawing and splicing processes.

[0080] In some embodiments, the device further includes a housing 4, and the output optical fiber 1, optical waveguide 2, and optical output head 3 are disposed inside the housing 4.

[0081] In some embodiments, the diameter of the first fiber core 101 is less than or equal to the diameter of the second fiber core 201.

[0082] When the diameter of the first fiber core 101 is designed to be less than or equal to the diameter of the second fiber core 201, the fundamental mode light (inner ring light, such as wavelength λ1) enters the larger diameter second fiber core 201 from the smaller diameter first fiber core 101, and its optical mode field expands smoothly and gradually, rather than undergoing a drastic mode abrupt change. By reducing the abrupt change in electric field distribution, reflection and energy leakage at the splice interface are effectively reduced, thereby keeping coupling loss at a low level. At the same time, the slightly larger second fiber core 201, in conjunction with the larger cladding diameter in the optical waveguide 2, increases the receiving aperture, allowing the outer ring light (higher-order modes) from the output fiber 1 to couple more fully into the modulation region of the optical waveguide 2, creating favorable conditions for subsequent divergence angle compression and mode purification using a tapered structure. The difference in diameter between the first fiber core 101 and the second fiber core 201 does not introduce significant transmission loss; on the contrary, by promoting a natural transition of the optical field and efficient reception, it provides key design freedom for achieving better overall beam quality.

[0083] In some embodiments, the diameter of each cladding layer 202 covering the second fiber core of the optical waveguide 2 is greater than or equal to the diameter of the corresponding cladding layer 102 covering the first fiber core, which significantly increases the effective receiving angle of the optical waveguide 2, enabling the outer ring light (higher-order mode) from the output fiber 1 to be more fully coupled into the cladding structure of the optical waveguide 2, and greatly reducing the transmission loss caused by interface reflection and mode field mismatch.

[0084] At the same time, the moderate increase in diameter creates ideal conditions for the smooth transition of the optical mode field. When light enters the optical waveguide 2 with a slightly larger diameter from the output optical fiber 1 with a smaller diameter, the optical field can naturally expand rather than change drastically, effectively avoiding the scattering loss and mode disturbance caused by the abrupt change in size in traditional structures.

[0085] This dimensional relationship works in conjunction with the tapered structure of optical waveguide 2 to achieve precise control of the outer ring light divergence angle. When the outer ring light enters the expanded cladding of optical waveguide 2, it undergoes a refraction effect at the tapered interface, causing its propagation path to be deflected outward, thereby effectively compressing the divergence angle of the output light.

[0086] It also enhances optical suppression capabilities. After entering the expanded cladding structure of optical waveguide 2, the transmitted light undergoes multiple reflections and mode field mismatches, significantly amplifying its divergence angle. Ultimately, it exceeds the fiber's receiving capacity and is squeezed out of the transmission path, thereby improving system stability. This not only achieves low-loss transmission of less than 0.5 dB but also significantly reduces manufacturing costs by simplifying the optical structure, providing an efficient and reliable beam control solution for high-power fiber lasers.

[0087] In some embodiments, the bevel angle V1 of the tapered end of the output fiber 1 and the bevel angle V2 of the tapered end of the optical waveguide 2 are key geometric parameters controlling the beam shaping effect. The larger bevel angle V1 of the fiber tapered end provides relatively rapid pre-compression and energy concentration for the beam (especially the outer ring higher-order modes); subsequently, the beam enters the tapered end with a smaller bevel angle V2, which provides a smoother, more gradual outward expansion path. The bevel angle V2 < bevel angle V1 ensures that the optical mode field can undergo a smooth transition from faster convergence to slower expansion, greatly optimizing the mode evolution process and effectively avoiding optical field disturbances and scattering losses caused by abrupt geometric changes. Thus, while efficiently compressing the beam divergence angle, the coupling loss at the splice point is minimized.

[0088] Furthermore, in the actual production process, minor process errors that may exist in the same batch of products can be compensated by finely adjusting the angle parameters of the tapered end of the output fiber 1 (V1), the tapered end of the optical waveguide 2 (V2), and the fusion end of the optical waveguide 2 and the optical output head 3 (V3). This can effectively offset the minor fluctuations caused by factors such as material properties and processing temperature, ensuring that all laser output optical devices produced in the same batch have a high degree of consistency in key performance indicators such as beam shaping effect, divergence angle control, and transmission loss, thereby significantly improving the overall accuracy and reliability of the products.

[0089] In some embodiments, the optical output head 3 is any one of a planar quartz optical output head, an arc-shaped quartz optical output head, or a spherical quartz optical output head.

[0090] As the final output end of the laser output optical device, the optical output head 3 can be any of the following: a planar quartz output head, an arc-shaped quartz output head, or a spherical quartz output head. This can achieve precise beam shaping, output efficiency optimization, and improved system reliability.

[0091] Specifically, the planar quartz output head provides a flat output interface, which is mainly used for beam collimation and protection of the internal optical path, reducing end-face reflection loss; The curved quartz output head uses its curved surface design to focus or diverge the beam, and can flexibly adjust the spot size and energy distribution to meet the spot requirements of different application scenarios. The spherical quartz output head uses a more complex curved surface structure to correct aberrations and achieve high-order beam shaping, ensuring high quality and high stability of the output light.

[0092] These quartz output heads are all made of quartz material with high light transmittance and excellent heat resistance, which can withstand the thermal effects and chemical corrosion of high-power lasers, thereby significantly reducing transmission loss (which can be controlled below 0.5dB) and improving device lifespan.

[0093] In addition, the unprocessed ends of the optical output head 3 and the optical waveguide 2 are integrated through end cap fusion technology, which ensures seamless connection of the optical path, further compresses the divergence angle and suppresses back reflection, ultimately enabling the laser output optical device to exhibit advantages of compact structure and reliable performance in fields such as industrial processing and medical equipment.

[0094] In some embodiments, the unprocessed end where the optical waveguide 2 is fused to the optical output head 3 can also be configured as a tapered end.

[0095] In laser output optics, the unprocessed end where the optical waveguide 2 and optical output head 3 are fused together is also set as a tapered end, with its bevel angle denoted as V3. The tapered end serves as a conversion and beam optimization output, acting as the last controllable interface before the optical signal leaves the optical waveguide 2 and enters the optical output head 3. It can further enhance the mode purity and suppress backlighting of the light field modulated by the tapered end. The tapered structure helps to cut off residual higher-order modes, causing them to dissipate in the tapered region due to failure to meet transmission conditions, thereby improving the purity of the fundamental mode light injected into the optical output head 3. At the same time, it can change the propagation angle of the transmitted light (such as the light reflected back from the end face of the optical output head 3), causing it to deviate from the original fiber core, effectively suppressing the impact of backlighting on the stability of the laser.

[0096] By adjusting the angle of the inclined cone V3, the spot size and divergence characteristics from the optical waveguide core to the optical output head 3 can be finely adjusted to achieve the most ideal mode field matching, ensuring that the laser energy is utilized and shaped by the optical output head in the most efficient way, and ultimately obtaining better output beam quality (BPP) and higher power extraction efficiency.

[0097] The inclined cone angle V3, together with the aforementioned inclined angles V1 and V2, constitutes a complete beam shaping sequence, realizing precise control of the entire process from pre-compression and main control to final optimized output.

[0098] In some embodiments, the tapered end of the output optical fiber 1 and the tapered end of the optical waveguide 2 are obtained by laser processing, mechanical grinding, polishing, chemical etching, polishing or fusion drawing processes.

[0099] Figure 8 This demonstrates the raw, unmodulated laser spot, whose morphology typically exhibits characteristics of energy dispersion, irregular contours, and large divergence angles; while Figure 9 This clearly demonstrates the final state of the same laser source light after pre-compression at the tapered end of the output fiber and main control at the tapered end of the waveguide, as described in this application. The comparison clearly shows that... Figure 9The light spot exhibits an ideal shape with highly concentrated energy, clear outline, and near-circular shape, indicating that the tapered structure of output fiber 1 effectively pre-compresses the outer ring light in the transmitted light, while the tapered structure of optical waveguide 2 further smooths the transition and precisely controls the optical mode field. The two work together to significantly compress the divergence angle of the output light and effectively suppress higher-order modes, thereby obtaining a high-quality output beam.

[0100] This application also provides a method for fabricating a laser output optical device, the method comprising: Step 101: Provide an output optical fiber, including at least one first fiber core and a cladding covering the first fiber core radially outward, for outputting a dot-ring beam; Step 102: Provide an optical waveguide, including at least one second fiber core and a cladding covering the second fiber core. Taper the cladding covering the second fiber core at one end of the optical waveguide to obtain a second tapered structure. The cross-section of the second tapered structure is annular, and the outer diameter of the second tapered structure gradually increases along the beam transmission direction. This is used to adjust the optical path of the point ring beam to adjust the divergence angle of the inner and outer ring beams. Step 103: An optical output head will be provided for outputting the beam adjusted by the optical waveguide; Step 104: Connect the output end of the output optical fiber to the second tapered end of the optical waveguide, and connect the other end of the optical waveguide to the optical output head.

[0101] The optical output head 3 can be selected as a flat, curved, or spherical quartz output head. In this example, a spherical quartz output head (size Φ8×20mm) is preferred.

[0102] Step 105: Install the fused components into the housing 4 to complete the assembly of the laser output optical device.

[0103] Specifically, the fused optical components are installed inside housing 4 to complete the final assembly. Housing 4 is made of aluminum alloy, and its inner surface is anodized to enhance heat dissipation and corrosion resistance. During assembly, a thermally conductive silicone pad is first laid inside the housing, and the optical components are precisely fixed in the predetermined positions to ensure optical path collimation.

[0104] This application also provides a laser, including the laser output optical device described above.

[0105] This application also provides a laser processing device, including the laser described above.

[0106] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0107] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A laser output optical device, characterized in that, Including those connected sequentially: The output optical fiber includes at least one first fiber core and a cladding covering the first fiber core, for outputting a point ring beam; An optical waveguide includes at least one second fiber core and a cladding covering the second fiber core. The cladding covering the second fiber core in at least a portion of the area near the output optical fiber includes a second tapered structure. The cross-section of the second tapered structure is annular, and the outer diameter of the second tapered structure gradually increases along the beam transmission direction. This structure is used to adjust the optical path of the point-ring beam to adjust the divergence angle of the inner and outer ring beams. An optical output head is used to output the light beam adjusted by the optical waveguide.

2. The laser output optical device according to claim 1, characterized in that, The cladding covering the first fiber core in at least a portion of the output fiber near the optical waveguide includes a first tapered structure, which is used to control the size of the divergence angle of the output beam from the output fiber.

3. The laser output optical device according to claim 2, characterized in that, The cladding covering the first fiber core includes a first cladding, and the first cladding near at least a portion of the optical waveguide includes a first tapered structure; Alternatively, the cladding covering the first fiber core may include a first cladding and a second cladding, wherein the second cladding near at least a portion of the optical waveguide may include a first tapered structure; Alternatively, the cladding covering the first fiber core may include a first cladding, a second cladding, and an outer cladding, wherein the outer cladding near at least a portion of the optical waveguide may include a first tapered structure.

4. The laser output optical device according to claim 1, characterized in that, The cladding covering the second fiber core includes a fifth cladding, and the fifth cladding near at least a portion of the output fiber includes a second tapered structure; Alternatively, the cladding covering the second fiber core may include a fifth cladding and a sixth cladding, wherein the sixth cladding near at least a portion of the output fiber may include a second tapered structure; Alternatively, the cladding covering the second fiber core may include a fifth cladding, a sixth cladding, and an outer cladding, wherein the outer cladding near at least a portion of the output fiber may include a second tapered structure.

5. The laser output optical device according to claim 1, characterized in that, At least a portion of the cladding covering the second fiber core near the optical output head includes a third conical structure, which is used to control the size of the divergence angle of the output beam from the optical waveguide.

6. The laser output optical device according to claim 5, characterized in that, The cladding covering the second fiber core includes a fifth cladding, and the fifth cladding near at least a portion of the optical output head includes a third conical structure; Alternatively, the cladding covering the second fiber core may include a fifth cladding and a sixth cladding, wherein the sixth cladding near at least a portion of the optical output head includes a third conical structure; Alternatively, the cladding covering the second fiber core may include a fifth cladding, a sixth cladding, and an outer cladding, wherein the outer cladding near at least a portion of the optical output head includes a third conical structure.

7. The laser output optical device according to claim 1, characterized in that, The diameter of the first fiber core is less than or equal to the diameter of the second fiber core.

8. A method for fabricating a laser output optical device, characterized in that, The method includes: An output optical fiber is provided, including at least one first fiber core and a cladding covering the first fiber core, for outputting a dot-ring beam; An optical waveguide is provided, including at least one second fiber core and a cladding covering the second fiber core. The cladding covering the second fiber core at one end of the optical waveguide is tapered to obtain a second tapered structure. The cross-section of the second tapered structure is annular, and the outer diameter of the second tapered structure gradually increases along the beam transmission direction. This is used to adjust the optical path of the point ring beam to adjust the divergence angle of the inner and outer ring beams. An optical output head is provided for outputting a beam of light adjusted by the optical waveguide; The output end of the output optical fiber is connected to the second tapered end of the optical waveguide, and the other end of the optical waveguide is connected to the optical output head.

9. A laser, characterized in that, include: The laser output optical device as described in any one of claims 1-7.

10. A laser processing device, characterized in that, include: The laser as described in claim 9.

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