White light super-continuum spectrum optical fiber beam combiner, light-emitting unit and preparation method of white light super-continuum spectrum optical fiber beam combiner

Abstract

The invention relates to the technical field of illumination, in particular to a white light super-continuum spectrum optical fiber beam combiner, a light-emitting unit and a preparation method of the white light super-continuum spectrum optical fiber beam combiner. The white light super-continuum spectrum optical fiber beam combiner comprises N2 first input optical fibers, (N-1) 2 second input optical fibers and a square output optical fiber; the one or more second input optical fibers are respectively arranged in gaps formed among the plurality of first input optical fibers, the square output optical fiber is welded at tapering and melting small opening ends of the first input optical fibers and the second input optical fibers, and N is a natural number greater than or equal to 2. The white light super-continuum spectrum optical fiber beam combiner can transmit energy of a spectral band in a high-quality mode, the color rendition degree is better than that of traditional white light illumination, meanwhile, the application requirement for high illumination brightness is met, and the problem that an existing illumination device is insufficient in brightness is effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of lighting technology, and in particular to a white light supercontinuum optical fiber combiner, a light-emitting unit and a preparation method thereof. Background Art

[0002] In the field of lighting technology, with the advancement of science and technology and people's increasing requirements for lighting quality, traditional lighting methods can no longer meet the needs of modern applications for high brightness, high color reproduction and wide spectrum coverage. Especially in the fields of stage lighting, film and television production, medical diagnosis, scientific research analysis and high-end display, more stringent standards are put forward for the performance of light sources. As an emerging light source technology, white light supercontinuum laser has become a potential solution to the above problems because it has both the coherence of lasers and the wide spectrum characteristics of sunlight.

[0003] The spectrum coverage of white light supercontinuum laser is extremely wide, covering the entire visible light band, thus making it possible to achieve natural and realistic color reproduction. In addition, through advanced beam combining technology, the brightness of the light source can be further improved to meet the needs of high-brightness lighting. As the core component in the optical fiber transmission system, the performance of the fiber combiner is directly related to the quality of the final output light. Through the carefully designed fiber combiner, not only can the non-visible light band be effectively filtered out and the stray light interference be reduced, but also the brightness and color purity of the light beam can be significantly improved, making the white light supercontinuum laser show greater advantages in practical applications.

[0004] However, the mainstream laser lighting solutions on the market still face many challenges. Although the traditional 3x1RGB fiber combiner technology can mix red, yellow and green lasers to produce white light, the discontinuity of the spectrum limits the color reproduction and makes it difficult to meet high fidelity requirements. This method is particularly limited in scenes that require precise color matching.

[0005] On the other hand, although the method of using blue light semiconductors to pump fluorescent materials to produce white light has achieved white light output to a certain extent, due to the efficiency loss and technical bottlenecks in the fluorescence conversion process, some key spectral components (such as saturated blue areas and infrared components) are often missing or insufficient. 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 new type of lighting system that can fully utilize the advantages of white light supercontinuum lasers while overcoming the defects of existing technologies has become an urgent problem to be solved in the current field of lighting technology. The present invention aims to achieve high efficiency, high brightness, and high color reproduction output of white light supercontinuum lasers through innovative fiber beam combining technology and spectrum optimization strategies, providing a more ideal light source solution for various high-end lighting applications. Summary of the invention

[0007] The purpose of the present invention is to provide a white-light supercontinuum fiber combiner, a light-emitting unit and a preparation method thereof. The white-light supercontinuum fiber combiner of the present invention can transmit the energy of the spectral band with high quality, and the color reproduction is more advantageous than that of traditional white light lighting. At the same time, it meets the application requirements of high lighting brightness and effectively solves the problem of insufficient brightness of existing lighting devices.

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

[0009] For example, for a white light supercontinuum fiber combiner with N=2, it includes 4 first input fibers, 1 second input fiber, and 1 square output fiber, wherein the first input fiber is a passive fiber with a core diameter of 20 μm and a cladding diameter of 125 μm, and the output fiber is a square passive fiber with a core diameter of 200 μm and a cladding diameter of 240 μm;

[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] And so on.

[0014] As a preferred embodiment of the technical solution, a quartz sleeve is further included, which is sleeved on 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 keep the end face structures of the first input optical fiber and the second input optical fiber unchanged during the tapered melting.

[0015] In a second aspect, the present invention further discloses a method for preparing the above-mentioned white light supercontinuum fiber combiner, comprising the following steps:

[0016] S1, in N 2 The outer sides of the first input optical fibers which are closely arranged are sheathed into a quartz sheath;

[0017] S2, (N-1) 2 The second input fiber is plugged into N 2 In the gap between the first input optical fibers, an optical fiber bundle is formed;

[0018] S3, melting and tapering the optical fiber bundle to obtain a fused and taper optical fiber bundle;

[0019] S4, cutting the fused-tapered fiber bundle evenly at the waist where the diameter is uniform, and fusing the cut fused-tapered fiber bundle with the square output fiber to obtain a white-light supercontinuum fiber combiner.

[0020] The preparation method of the white-light supercontinuum fiber combiner of the present invention mainly comprises the steps of cladding treatment, beam forming, tapering, cutting and welding. Under the special fiber arrangement mode of the first input fiber and the second input fiber, the wavelength is selected through a large tapering ratio, and finally the output is output through a square output fiber. Not only can the output of the white-light supercontinuum laser with high efficiency, high brightness and high color reproduction be achieved, but also a lighting array can be formed for large-area application.

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

[0022] As a preferred embodiment of the present technical solution, in step S2, the second input optical fiber is the first input optical fiber after cladding corrosion, or other input optical fiber that meets the required core size.

[0023] As a preferred embodiment of the present technical solution, in step S3, when the fusion taper is formed, the adiabatic taper condition needs to be satisfied: |dr / dz|≤r(β1-β2) / 2π,

[0024] Among them, dr / dz is the angle of the tapered transition region, r is the radius of 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 next higher-order mode.

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

[0026] As a preferred embodiment of the present technical solution, in step S3, when the fusion taper is performed, the brightness conservation condition needs to be satisfied:

[0027]

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

[0029] The adiabatic taper condition can ensure that the optical fiber bundle does not produce loss during the taper process, while the brightness conservation condition can ensure that the light transmitted by the fused-tapered fiber bundle (TFB) can be received by the output optical fiber. Therefore, by satisfying both the adiabatic taper and brightness conservation conditions, a lighting fiber combiner with high transmission efficiency in the visible light band can be prepared.

[0030] As a preferred embodiment of the present technical solution, in step S3, when the fusion taper is formed, a high-power fiber optic taper machine is used for the fusion taper, and the taper length is controlled to be not less than 20 cm. The taper length here is larger than that of a general fiber optic combiner, which is beneficial for the fiber optic combiner to select the wavelength.

[0031] As a preferred embodiment of the present technical solution, in step S4, during the cutting, a large-diameter optical fiber cutting knife is used to locate the waist of the fused-tapered optical fiber bundle under a microscope for smooth cutting, and the cutting angle is controlled within 1° by setting the fusion parameters.

[0032] As a preferred embodiment of the present technical solution, the present invention can further perform device packaging on the prepared white light supercontinuum fiber combiner. When performing device packaging, a clean circular steel tube packaging assembly with an inner diameter slightly larger than that of the white light supercontinuum fiber combiner can be first selected for packaging. Specifically, the un-tapered area and the output optical fiber are respectively placed in the circular steel tube packaging assembly, so that the tapered area and the tapered waist are suspended in the air, and then the circular steel tube is placed in a water-cooled packaging shell, and the circular steel tube and the water-cooled packaging shell are bonded using a high thermal conductivity optical adhesive.

[0033] In the third aspect, the present invention also discloses a white-light supercontinuum luminescence unit, comprising 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 said white-light supercontinuum fiber combiners should also fall within the protection scope of the present invention.

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

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

[0036] The white light supercontinuum optical fiber combiner of the present invention comprises N 2 First input optical fiber, (N-1) 2 A second input optical fiber and a square output optical fiber, wherein the plurality of first input optical fibers are distributed in a square array, and one or more second input optical fibers are respectively arranged in the gaps formed between the plurality of first input optical fibers, and the square output optical fiber is fused to the small-mouthed ends of the first input optical fiber and the second input optical fiber, wherein N is a natural number greater than or equal to 2. Firstly, the first input optical fibers are distributed in a square array, and this arrangement can maximize the use of space, minimize the gaps between the input optical fibers, thereby reducing the loss of light during transmission and improving the efficiency of light utilization, while the second input optical fiber is filled in the gaps between the first input optical fibers, further reducing the possibility of light leakage and ensuring that more light energy is effectively guided to the output optical fiber; the small-mouthed ends of the first input optical fiber and the second input optical fiber are fused together and connected to the square output optical fiber, which not only helps to maintain the uniformity and stability of the light beam and ensure the continuous transmission of the optical signal, but also improves the overall light output efficiency and lighting effect by reducing the light loss at the optical fiber connection. Therefore, the compact input fiber arrangement and efficient tapered melting technology of the present invention reduce the scattering and reflection losses of light during transmission, improve the quality of the light beam, and achieve high-efficiency, high-brightness, and high-color-reproduction output of white-light supercontinuum lasers, bringing a revolutionary breakthrough in the field of lighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

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

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

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

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

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

[0044] Description of reference numerals:

[0045] 1: first input optical fiber; 2: quartz sleeve; 3: output optical fiber; 4: second input optical fiber; 5: steel packaging shell; 6: water-cooled packaging shell. DETAILED DESCRIPTION

[0046] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Example 1

[0050] like Figure 1 As shown, this embodiment uses N=2 to illustrate the structure of the white-light supercontinuum fiber combiner and its preparation method.

[0051] First, for a white-light supercontinuum fiber combiner with N=2, it includes 4 first input fibers, 1 second input fiber and 1 large-mode-field square output fiber, wherein the 4 first input fibers are distributed in a square array, the 1 second input fiber is arranged in the gap formed between the 4 first input fibers, and the large-mode-field square output fiber is fused to the small-mouth ends of the first input fiber and the second input fiber that are tapered and fused.

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

[0053] S11, optical fiber pretreatment: prepare five first input optical fibers, the core and cladding diameters of the first input optical fibers are 20 and 125um respectively, use a wire stripper or a coating thermal stripper to strip off a section of 8cm of coating, and wipe the bare fiber part with anhydrous alcohol for standby use; perform cladding corrosion treatment on one of the first input optical fibers, take a stripped first input optical fiber, immerse it in a hydrofluoric acid solution, and after a certain corrosion time, obtain a second input optical fiber with a cladding of 100um;

[0054] Insert four pre-treated first input optical fibers into a low-refractive-index quartz tube with an inner diameter of 350 um, an outer diameter of 400 um, and a length of 10 cm;

[0055] S2. Carefully insert the second input optical fiber into the gaps between the four first input optical fibers to form an optical fiber bundle, such as Figure 1 As shown;

[0056] S3, using a high-power optical fiber taper machine to melt-tap the optical fiber bundle to obtain a melt-tapaped optical fiber bundle with a taper waist diameter of 240m and a taper length of not less than 20cm;

[0057] S4. Use a large-diameter fiber cleaver to find the waist of the fused-tapered fiber bundle with a diameter of 240um under a microscope, set the cutting parameters, cut smoothly, and control the cutting angle within 1o; further use a fiber fusion splicer to set the fusion parameters and fuse the fused-tapered fiber bundle with a square output fiber with a diameter of 240um, such as Figure 2 As shown;

[0058] S5, applying ultraviolet UV glue with high thermal conductivity on the tapered area and tapered waist of the above-mentioned white light supercontinuum optical fiber combiner, and then using a clean circular steel packaging shell with an inner diameter slightly larger than the fused-tapered optical fiber bundle and a length of 30 cm to encapsulate the above-prepared white light supercontinuum optical fiber combiner;

[0059] S18: Put the circular steel packaging shell encapsulating the white light supercontinuum optical fiber combiner into a water-cooled packaging shell, and use a high thermal conductivity optical glue to bond the circular steel packaging shell to the water-cooled packaging shell. Figure 3 shown.

[0060] Example 2

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

[0062] The preparation method is basically the same as that of Example 1.

[0063] Example 3

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

[0065] The preparation method is basically the same as that of 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 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, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 white light supercontinuum optical fiber combiner, characterized in that: Including N 2 First input optical fiber, (N-1) 2 second input optical fibers and a square output optical fiber, the plurality of first input optical fibers are distributed in a square array, one or more second input optical fibers are respectively arranged in gaps formed between the plurality of first input optical fibers, and the square output optical fiber is fused to the small-mouthed ends of the first input optical fiber and the second input optical fiber where N is a natural number greater than or equal to 2.

2. The white light supercontinuum fiber combiner according to claim 1, characterized in that: It also includes a quartz sleeve, which is sleeved on the outside of the first input optical fiber, and the refractive index of the quartz sleeve is smaller than that of the first input optical fiber.

3. The method for preparing the white light supercontinuum fiber combiner according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1, in N 2 The outer sides of the first input optical fibers which are closely arranged are sheathed into a quartz sheath; S2, (N-1) 2 The second input fiber is plugged into N 2 In the gap between the first input optical fibers, an optical fiber bundle is formed; S3, melting and tapering the optical fiber bundle to obtain a fused and taper optical fiber bundle; S4, cutting the fused-tapered fiber bundle evenly at the waist where the diameter is uniform, and fusing the cut fused-tapered fiber bundle with the square output fiber to obtain a white-light supercontinuum fiber combiner.

4. The preparation method according to claim 3, characterized in that: In step S1, before using the first input optical fiber, a 6-10 cm coating layer is stripped off using a wire stripper or a coating thermal stripper, and then the bare fiber portion is wiped clean using anhydrous ethanol.

5. The preparation method according to claim 3, characterized in that: In step S2, the second input optical fiber is the first input optical fiber after cladding corrosion, or other input optical fibers that meet the required core size.

6. The preparation method according to claim 3, characterized in that: In step S3, during the fusion taper, the adiabatic taper condition needs to be satisfied: |dr / dz|≤r(β1-β2) / 2π, Among them, dr / dz is the angle of the tapered transition region, r is the radius of 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 next higher-order mode.

7. The preparation method according to claim 3, characterized in that: In step S3, when the fused taper is formed, the brightness conservation condition needs to be satisfied: Among them, IB in is the input integrated brightness, IB out is the integrated brightness of the output, N is the number of the first input optical fiber, D in is the core diameter of the first input optical fiber, D out is the output fiber core diameter; NA in is the numerical aperture of the first input fiber, NA out is the numerical aperture of the square output fiber.

8. The preparation method according to claim 3, characterized in that: In step S3, during the fusion taper drawing, the taper length is not less than 20 cm.

9. The preparation method according to claim 3, characterized in that: In step S4, during the cutting, the cutting angle is controlled within 1°.

10. A white light supercontinuum luminescence unit, characterized in that: It comprises a plurality of white-light supercontinuum fiber combiners as described in any one of claims 1 to 2, and the output surfaces of the plurality of white-light supercontinuum fiber combiners are arranged in an array.

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