A white light supercontinuum fiber combiner, a light emitting unit and a preparation method thereof

Abstract

This invention relates to the field of lighting technology, and in particular to a white light supercontinuum fiber combiner, a light-emitting unit, and a method for fabricating the same, including N 2 One first input optical fiber, (N-1) 2 The first input fibers consist of a second input fiber and a square output fiber. Multiple first input fibers are arranged in a square array. One or more second input fibers are respectively disposed in the gaps formed between the multiple first input fibers. The square output fiber is fused to the tapered fused ends of the first and second input fibers. N is a natural number greater than or equal to 2. This invention's white light supercontinuum fiber combiner can transmit spectral energy with high quality, offering superior color reproduction compared to traditional white light illumination. It also meets the application requirements for high illumination brightness, effectively solving the problem of insufficient brightness in existing lighting devices.

Description

Technical Field

[0001] This invention relates to the field of lighting technology, and in particular to a white light supercontinuum fiber combiner, a light-emitting unit, and a method for fabricating the same. Background Technology

[0002] In the field of lighting technology, with the advancement of technology and people's increasing demands for lighting quality, traditional lighting methods can no longer meet the modern applications' requirements for high brightness, high color fidelity, and wide spectral coverage. This is especially true in fields such as stage lighting, film and television production, medical diagnosis, scientific research and analysis, and high-end displays, where even more stringent standards are being placed on the performance of light sources. White supercontinuum lasers, as an emerging light source technology, possess both the coherence of lasers and the wide spectral characteristics of sunlight, making them a potential solution to these problems.

[0003] White supercontinuum lasers boast an extremely wide spectral coverage, encompassing the entire visible light spectrum, thus enabling the reproduction of natural and realistic colors. Furthermore, advanced beam combining technology can further enhance the brightness of the light source, meeting the demands of high-brightness illumination. As a core component of optical fiber transmission systems, the performance of the fiber combiner directly affects the quality of the final output light. A carefully designed fiber combiner can effectively filter out non-visible light bands, reducing stray light interference, and significantly improve beam brightness and color purity, giving white supercontinuum lasers greater advantages in practical applications.

[0004] However, current mainstream laser lighting solutions still face many challenges. Traditional 3x1RGB fiber combiner technology, while capable of mixing red, yellow, and green lasers to produce white light, suffers from limited color fidelity due to spectral discontinuities, making it difficult to achieve high fidelity. This limitation is particularly pronounced in scenarios requiring precise color matching.

[0005] On the other hand, while using blue semiconductors to pump fluorescent materials to generate white light achieves white light output to some extent, efficiency losses and technical bottlenecks during the fluorescence conversion process often lead to the absence or insufficiency of some key spectral components (such as the saturated blue region and infrared components). This not only affects the color saturation of the light source but also limits its performance in specific applications, such as precise irradiation and diagnosis of skin tissue in medical lighting.

[0006] Therefore, developing a novel lighting system that can fully utilize the advantages of white supercontinuum lasers while overcoming the shortcomings of existing technologies has become an urgent problem to be solved in the field of lighting technology. This invention aims to achieve efficient, high-brightness, and high-color-fidelity output of white supercontinuum lasers through innovative fiber combining technology and spectral optimization strategies, providing a more ideal light source solution for various high-end lighting applications. Summary of the Invention

[0007] The purpose of this invention is to provide a white light supercontinuum fiber combiner, a light-emitting unit, and a method for fabricating the same. The white light supercontinuum fiber combiner of this invention can transmit energy in the spectral band with high quality, and its color reproduction is superior to that of traditional white light illumination. At the same time, it meets the application requirements for high illumination brightness and effectively solves the problem of insufficient brightness in existing lighting devices.

[0008] In a first aspect, the present invention provides a white light supercontinuum fiber combiner, comprising N 2 One first input fiber, (N-1) 2 A second input fiber and a square output fiber, a plurality of first input fibers are distributed in a square array, one or more second input fibers are respectively disposed in the gaps formed between the plurality of first input fibers, and the square output fiber is fused to the tapered fused ends of the first input fibers and the second input fibers, wherein N is a natural number greater than or equal to 2.

[0009] For example, a white light supercontinuum fiber combiner with N=2 includes four first input fibers, one second input fiber, and one square output fiber. The first input fibers are passive fibers with a core diameter of 20μm and a cladding diameter of 125μm, and the output fiber is a square passive fiber with a core diameter of 200μm and a cladding diameter of 240μm.

[0010] For a white light supercontinuum fiber combiner with N=3, it includes 9 first input fibers, 4 second input fibers and 1 square output fiber;

[0011] For a white light supercontinuum fiber combiner with N=4, it includes 16 first input fibers, 9 second input fibers, and 1 square output fiber.

[0012] For a white light supercontinuum fiber combiner with N=5, it includes 25 first input fibers, 16 second input fibers, and 1 square output fiber.

[0013] The same principle applies to the others.

[0014] As a preferred embodiment of this technical solution, a quartz sleeve is further included. The quartz sleeve is fitted onto the outside of the first input optical fiber, and the refractive index of the quartz sleeve is lower than that of the first input optical fiber. The low-refractive-index quartz sleeve is mainly used to ensure that the end-face structure of the first and second input optical fibers does not change during tapering and melting.

[0015] Secondly, the present invention also discloses a method for fabricating the above-mentioned white light supercontinuum fiber combiner, comprising the following steps:

[0016] S1, in N 2 A quartz sleeve is inserted into the outer side of the first closely spaced input optical fiber;

[0017] S2, (N-1) 2 N is inserted into the second input fiber. 2 A fiber bundle is formed in the gap of the first input fiber;

[0018] S3. Melt and taper the fiber bundle to obtain a fused tapered fiber bundle;

[0019] S4. Cut the fused tapered fiber bundle flat at the waist of the uniform diameter, and then fusion splice the cut fused tapered fiber bundle with the square output fiber to obtain a white light supercontinuum fiber combiner.

[0020] The fabrication method of the white light supercontinuum fiber combiner of the present invention mainly includes cladding treatment, bundle assembly, tapering, cutting and splicing. With the special fiber arrangement of the first and second input fibers, wavelength selection is performed after a large tapering ratio, and finally the output is achieved through a square output fiber. This not only enables the output of white light supercontinuum laser with high efficiency, high brightness and high color fidelity, but also allows it to be used in large-area applications as an illumination array.

[0021] As a preferred embodiment of this technical solution, in step S1, before using the first input optical fiber, a 6-10cm section of the coating layer is removed using wire strippers or a coating heat stripper, and then the bare fiber portion is wiped clean with anhydrous ethanol.

[0022] As a preferred embodiment of this technical solution, in step S2, the second input fiber is the first input fiber after cladding etching, or other input fibers that meet the required core size.

[0023] In a preferred embodiment of this technical solution, during the molten tapering process in step S3, the adiabatic tapering condition must be met: |dr / dz|≤r(β1-β2) / 2π.

[0024] Where dr / dz is the angle of the tapered transition region, r is the radius at a certain point in the tapered transition region, β1 is the local propagation constant of the fundamental mode, and β2 is the local propagation constant of the second-higher-order mode.

[0025] The slower the waveguide structure changes in the tapered transition region, the better the light can be confined within the tapered region for propagation, and thus the higher the light transmission efficiency.

[0026] In a preferred embodiment of this technical solution, during the molten tapering process in step S3, the brightness conservation condition must also be met:

[0027]

[0028] Among them, IB in For the integrated brightness input, IB out The output integrated brightness, where N is the number of the first input optical fibers, and D is the output integrated brightness. in D is the diameter of the first input fiber core. out NA is the core diameter of the square output fiber. in NA is the numerical aperture of the first input fiber. out The numerical aperture is for a square output optical fiber.

[0029] The adiabatic tapering condition ensures that no loss occurs in the fiber bundle during the tapering process, while the brightness conservation condition ensures that all light transmitted by the fused tapered fiber bundle (TFB) can be received by the output fiber. Therefore, by simultaneously satisfying the adiabatic tapering and brightness conservation conditions, a high-efficiency illumination fiber combiner in the visible light band can be prepared.

[0030] As a preferred embodiment of this technical solution, in step S3, during the fusion tapering process, a high-power fiber tapering machine is used for fusion tapering, and the taper length is controlled to be no less than 20cm. The taper length here is larger than that of a typical fiber optic combiner, which is beneficial for the fiber optic combiner to select the wavelength.

[0031] As a preferred embodiment of this technical solution, in step S4, during the cutting process, a large-diameter fiber optic cleaver is used to accurately locate the waist of the fused tapered fiber bundle under a microscope for flat cutting. By setting the fusion splicing parameters, the cutting angle is controlled within 1°.

[0032] As a preferred embodiment of this technical solution, the present invention can further encapsulate the prepared white light supercontinuum fiber combiner. When encapsulating the device, a clean circular steel tube encapsulation assembly with an inner diameter slightly larger than that of the white light supercontinuum fiber combiner can be selected for encapsulation. Specifically, the uncontracted tapered area and the output fiber are placed in the circular steel tube encapsulation assembly, so that the tapered area and the tapered waist are suspended. Then, the circular steel tube is placed in the water-cooled encapsulation shell, and the circular steel tube and the water-cooled encapsulation shell are bonded together with a high thermal conductivity optical adhesive.

[0033] Thirdly, the present invention also discloses a white light supercontinuum light-emitting unit, including a plurality of white light supercontinuum fiber combiners as described in any one of claims 1-2, and the output surface array arrangement of the plurality of white light supercontinuum fiber combiners should also fall within the protection scope of the present invention.

[0034] The white light supercontinuum light-emitting unit can further expand the illumination area by arranging the output end of the aforementioned white light supercontinuum fiber combiner.

[0035] The white light supercontinuum fiber combiner of the present invention has at least the following beneficial effects:

[0036] The white light supercontinuum fiber combiner of the present invention includes N 2 One first input fiber, (N-1) 2 The system comprises one second input fiber and one square output fiber. Multiple first input fibers are arranged in a square array, and one or more second input fibers are respectively positioned in the gaps formed between the first input fibers. The square output fiber is fused to the tapered ends of the first and second input fibers. Here, N is a natural number greater than or equal to 2. Firstly, the square array arrangement of the first input fibers maximizes space utilization, minimizing the gaps between the input fibers and reducing light loss during transmission, thus improving light utilization efficiency. The second input fibers fill the gaps between the first input fibers, further reducing the possibility of light leakage and ensuring that more light energy is effectively guided into the output fiber. The fusion of the tapered ends of the first and second input fibers and their connection to the square output fiber not only helps maintain beam uniformity and stability, ensuring continuous optical signal transmission, but also improves overall light output efficiency and illumination effect by reducing light loss at the fiber connection. Therefore, the compact input fiber arrangement and efficient tapered fusion technology of this invention reduce the scattering and reflection loss of light during transmission, improve the quality of the beam, and realize the output of white supercontinuum laser with high efficiency, high brightness and high color fidelity, bringing a revolutionary breakthrough to the field of lighting. Attached Figure Description

[0037] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a view of the input fiber end face (N=2) of a white light supercontinuum fiber combiner according to the present invention;

[0039] Figure 2 This is a side view of the structure of a white light supercontinuum fiber combiner according to the present invention (N=2);

[0040] Figure 3 This is a schematic diagram of the packaging structure of the white light supercontinuum fiber combiner of the present invention;

[0041] Figure 4 This is a view of the input fiber end face (N=3) of a white light supercontinuum fiber combiner according to the present invention;

[0042] Figure 5 This is a view of the input fiber end face (N=4) of a white light supercontinuum fiber combiner according to the present invention;

[0043] Figure 6 This is an end view of the white light supercontinuum luminescent unit of the present invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1: First input optical fiber; 2: Quartz sleeve; 3: Output optical fiber; 4: Second input optical fiber; 5: Steel encapsulation shell; 6: Water-cooled encapsulation shell. Detailed Implementation

[0046] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0049] Example 1

[0050] like Figure 1 As shown, this embodiment illustrates the structure and fabrication method of a white light supercontinuum fiber combiner with N=2.

[0051] First, for a white light supercontinuum fiber combiner with N=2, it includes four first input fibers, one second input fiber, and one large-mode-field square output fiber. The four first input fibers are arranged in a square array, and the one second input fiber is placed in the gap formed between the four first input fibers. The large-mode-field square output fiber is fused to the tapered fused ends of the first and second input fibers.

[0052] Secondly, the fabrication method for a white light supercontinuum fiber combiner with N=2 includes the following steps:

[0053] S11. Fiber Pretreatment: Prepare five first input fibers with core and cladding diameters of 20 μm and 125 μm, respectively. Use wire strippers or a coating heat stripper to remove an 8 cm section of coating and clean the bare fiber with anhydrous alcohol. Perform cladding etching on one of the first input fibers. Take the stripped first input fiber and immerse it in hydrofluoric acid solution. After a certain etching time, a second input fiber with a cladding of 100 μm is obtained.

[0054] Four pre-treated first input optical fibers were inserted into a low-refractive-index quartz sleeve with an inner diameter of 350 μm, an outer diameter of 400 μm, and a length of 10 cm.

[0055] S2. Carefully insert the second input fiber into the gap between the four first input fibers to form a fiber bundle, as shown below. Figure 1 As shown;

[0056] S3. Use a high-power fiber taper machine to fused taper the fiber bundle to obtain a fused taper fiber bundle with a waist diameter of 240 μm and a taper length of not less than 20 cm.

[0057] S4. Using a large-diameter fiber optic cleaver, locate the 240µm diameter waist of the fused tapered fiber bundle under a microscope, set the cleaving parameters, and cut smoothly, controlling the cleaving angle within 1°. Further, using a fiber optic fusion splicer, set the splicing parameters and fuse the fused tapered fiber bundle with a 240µm diameter square output fiber. Figure 2 As shown;

[0058] S5. Apply a high thermal conductivity UV adhesive to the tapered region and waist of the white light supercontinuum fiber combiner, and then encapsulate the white light supercontinuum fiber combiner prepared above with a clean circular steel encapsulation shell with an inner diameter slightly larger than the fused tapered fiber bundle and a length of 30cm.

[0059] S18: Place the circular steel casing containing the white-light supercontinuum fiber combiner into the water-cooled casing. The circular steel casing and the water-cooled casing are bonded together using highly thermally conductive optical adhesive. Figure 3 As shown.

[0060] Example 2

[0061] like Figure 4 As shown, when N=3, a white light supercontinuum fiber combiner can be fabricated, which includes 9 first input fibers, 4 second input fibers, and 1 square output fiber with a large mode field.

[0062] Its preparation method is basically the same as that in Example 1.

[0063] Example 3

[0064] like Figure 5 As shown, when N=4, a white light supercontinuum fiber combiner can be fabricated, which includes 16 first input fibers, 9 second input fibers, and 1 square output fiber with a large mode field.

[0065] Its preparation method is basically the same as that in Example 1.

[0066] Example 4

[0067] like Figure 6 As shown, this embodiment provides a white light supercontinuum light-emitting unit including the above-mentioned white light supercontinuum fiber combiner, wherein the output surfaces of the four white light supercontinuum fiber combiners are arranged in an array.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fiber combiner for transmitting white supercontinuum laser light, characterized in that, Including N 2 One first input fiber, (N-1) 2 A second input fiber and a square output fiber, a plurality of first input fibers are distributed in a square array, one or more second input fibers are respectively disposed in the gaps formed between the plurality of first input fibers, and the square output fiber is fused to the tapered fused ends of the first input fibers and the second input fibers, wherein N is a natural number greater than or equal to 2; The method for fabricating the fiber combiner for transmitting white supercontinuum laser light includes the following steps: S1, in N 2 A quartz sleeve is inserted into the outer side of the first closely spaced input optical fiber; S2, (N-1) 2 N is inserted into the second input fiber. 2 An optical fiber bundle is formed in the gap of the first input optical fiber; S3. Melt and taper the fiber bundle to obtain a fused tapered fiber bundle; S4. Cut the fused tapered fiber bundle flat at the waist where the diameter is uniform, and then fusion splice the cut fused tapered fiber bundle with the square output fiber to obtain a fiber combiner for transmitting white supercontinuum laser. In step S2, the second input fiber is the first input fiber after cladding etching.

2. The fiber combiner for transmitting white supercontinuum laser light according to claim 1, characterized in that, It also includes a quartz sleeve, which is fitted over the outside of the first input optical fiber, and the refractive index of the quartz sleeve is less than that of the first input optical fiber.

3. The fiber combiner for transmitting white supercontinuum laser light according to claim 1, characterized in that, In step S1, before using the first input optical fiber, a 6-10cm section of the coating is removed using wire strippers or a coating thermal stripper, and then the bare fiber portion is wiped clean with anhydrous ethanol.

4. The fiber combiner for transmitting white supercontinuum laser light according to claim 1, characterized in that, In step S3, during the molten tapering process, the adiabatic tapering condition must be met: |dr / dz| ≤ r(β1-β2) / 2π. Where dr / dz is the angle of the tapered transition region, r is the radius at a certain point in the tapered transition region, β1 is the local propagation constant of the fundamental mode, and β2 is the local propagation constant of the second-higher-order mode.

5. The fiber combiner for transmitting white supercontinuum laser light according to claim 1, characterized in that, In step S3, during the molten tapering process, the brightness conservation condition must be met: in, IB in For the integrated brightness input, IB out For the integrated brightness of the output, N This represents the number of fibers in the first input fiber. D in The diameter of the first input fiber core. D out The diameter of the output optical fiber core; NA in The numerical aperture of the first input fiber. NA out The numerical aperture is for a square output optical fiber.

6. The fiber combiner for transmitting white supercontinuum laser light according to claim 1, characterized in that, In step S3, during the melting and tapering process, the tapering length is not less than 20cm.

7. The fiber combiner for transmitting white supercontinuum laser light according to claim 1, characterized in that, In step S4, during the cutting process, the cutting angle is controlled at 1°. o Within.

8. A white light supercontinuum luminescent unit, characterized in that, It includes multiple fiber optic combiners for transmitting white supercontinuum lasers as described in any one of claims 1-2, and the output surfaces of the multiple fiber optic combiners for transmitting white supercontinuum lasers are arranged in an array.

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