Columnar side-emitting optical fiber diffuser and manufacturing method thereof
By using femtosecond laser to etch the dot matrix structure inside the fiber core and coating sapphire powder on the outer surface, the problem of uneven light output in traditional diffuse optical fibers in high-power laser applications is solved, and the uniformity of optical power distribution is achieved and efficient processing.
Patent Information
- Application Number
- CN202411562554.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-14
AI Technical Summary
Traditional diffusing optical fibers have problems with uneven light output in high-power laser applications, and the materials of colloids and scattered particles are difficult to withstand high-power lasers, and the dispersant ratio is difficult and processing efficiency is low.
Femtosecond laser technology is used to etch the dot matrix structure inside the fiber core to form a columnar side luminescent fiber diffuser to ensure that the light signal is evenly scattered on the side of the fiber, and coat sapphire powder on the outer surface to enhance the lateral luminescence performance.
It realizes uniformity of optical power distribution, is suitable for high-power laser applications, simplifies manufacturing processes, improves processing efficiency, and avoids the problem of dispersed particles and processing complexity.
Smart Images
Figure CN119439366A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of optical fiber diffusers, and in particular to a columnar side-emitting optical fiber diffuser and a manufacturing method thereof. Background Art
[0002] Diffuse fiber is a specially designed fiber that scatters light evenly along its length, rather than just at the end of the fiber. This fiber introduces a specific scattering structure or material into the core or on the surface, so that part of the light is scattered out of the fiber surface during propagation, thus forming a uniform or specifically distributed luminous effect along the length of the fiber.
[0003] In the traditional manufacturing process of diffuse optical fiber, scattering particles are usually added to colloids or other media, and the mixture is coated on the surface of the optical fiber or embedded inside the optical fiber. The materials of the colloids and scattering particles used traditionally are usually not able to withstand high-power lasers. And because the power of light decays exponentially when it propagates in the optical fiber, the light intensity at different positions in the optical fiber will be different. The effect of the scattering particles in the optical fiber will also make the distribution of the luminous body uneven, which may be stronger at one end of the optical fiber and weaker at the other end. On the other hand, to achieve uniform light emission, the ratio and distribution of the scattering particles must be very precise, which will lead to difficult dispersant ratio and low processing efficiency.
[0004] To this end, we designed a columnar side-emitting optical fiber diffuser and its manufacturing method to solve the above problems. Summary of the invention
[0005] The purpose of the present invention is to solve the problem that the materials of colloids and scattering particles traditionally used in the prior art are usually unable to withstand high-power lasers. And because the power of light decays exponentially when it propagates in the optical fiber, the light intensity at different positions in the optical fiber will be different. The effect of the scattering particles in the optical fiber will also make the distribution of the light emitter uneven, which may emit stronger light at one end of the optical fiber and weaker light at the other end. On the other hand, to achieve uniform light emission, the proportion and distribution of the scattering particles must be very precise, which will lead to the disadvantages of difficult dispersant proportioning and low processing efficiency. A columnar side-emitting optical fiber diffuser and a method for making the diffuser are proposed, which can achieve uniform light power distribution, are suitable for high-power laser applications, and have a simple manufacturing process and high efficiency.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for manufacturing a columnar side-emitting optical fiber diffuser comprises the following steps: Step 1, selecting a transmission optical fiber having an optical fiber coating layer, an optical fiber cladding and an optical fiber core structure, connecting one end of the transmission optical fiber to an optical fiber connector, and removing the optical fiber coating layer and the optical fiber cladding at the other end to expose the optical fiber core portion; Step 2, fix the optical fiber core on a glass slide, place the glass slide on a three-dimensional electric translation stage, focus the femtosecond laser near the optical fiber core through a microscope objective, perform a femtosecond laser etching operation on the optical fiber core on the glass slide, and etch a lattice structure on the optical fiber core to form a diffuse core; Step 3, after completing femtosecond laser etching, clean the diffuse fiber core to remove tiny debris and residues generated during the processing; Step 4, immersing the dispersed fiber core in a frosting solution prepared by mixing frosting powder and hydrochloric acid in a certain proportion for roughening treatment; Step 5: After the dispersed fiber core is roughened, sapphire powder is coated on the outer surface of the dispersed fiber core.
[0007] Further preferably, in step 1, the optical fiber connector connected to one end of the transmission optical fiber is an optical fiber connector of model SMA905.
[0008] Further preferably, in step 2, when the optical fiber core on the glass slide is subjected to femtosecond laser etching, the repetition frequency of the femtosecond laser is 1000 Hz, the pulse width is 50 femtoseconds, the pulse duration of the femtosecond laser is in the range of 10 seconds to 1000 femtoseconds, the laser power is 0.7 mW, and the microscope objective lens is selected with a magnification of 20 times and a numerical aperture of 0.45.
[0009] Further preferably, in step 2, the diffuse core formed after etching a lattice structure on the optical fiber core with a femtosecond laser is divided into a diffuse core front section, a diffuse core middle section and a diffuse core back section; from the diffuse core front section to the diffuse core middle section and then to the diffuse core back section, the aperture of the holes on the etched lattice structure gradually increases, the spacing between the holes gradually decreases, and the number of holes gradually increases.
[0010] Further preferably, in step 4, the weight ratio of frosting powder to hydrochloric acid in the prepared frosting liquid is 3:1.
[0011] Further preferably, in step 5, the sapphire powder is firmly attached to the surface of the diffused fiber core using epoxy optical glue with the model name of Epo-Tek301.
[0012] A columnar side-emitting optical fiber diffuser is manufactured using the method for manufacturing a columnar side-emitting optical fiber diffuser, comprising an optical fiber connector, a transmission optical fiber and a diffusion core, wherein the transmission optical fiber comprises an optical fiber coating layer, an optical fiber cladding and an optical fiber core, wherein the outer surface of the optical fiber core is sequentially coated with the optical fiber cladding and the optical fiber coating layer, and the diffusion core is connected to one end of the optical fiber core, and a lattice structure is etched inside the core of the diffusion core by a femtosecond laser, wherein the aperture of the lattice structure gradually increases from the front section to the rear section, the spacing between the holes gradually decreases, and the number of holes gradually increases.
[0013] Further preferably, one end of the transmission optical fiber is connected to the optical fiber connector, and the other end is connected to the diffuse fiber core.
[0014] Further preferably, the outer surface of the dispersed fiber core is sequentially coated with a sapphire powder layer, a fiber cladding layer and a fiber coating layer.
[0015] Further preferably, the optical fiber connector is a SMA905 optical fiber connector.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention uses femtosecond laser technology to etch a lattice structure inside the fiber core, so that the light signal is evenly scattered on the side of the optical fiber, effectively avoiding the problem of uneven light output caused by the traditional use of dispersed particles, especially in high-power laser applications; compared with the traditional method of adding dispersed particles to glue, the lattice structure used in the present invention can not only achieve uniform light scattering, but also withstand higher laser power, avoiding the problem of damage or failure caused by the dispersed particles being unable to withstand high power. In addition, by accurately etching the lattice structure inside the fiber core with a femtosecond laser, the lattice aperture and spacing can be fine-tuned according to actual needs, ensuring that the optical fiber can achieve the optimal light scattering effect in different sections, improving the design flexibility and processing accuracy, and compared with the traditional dispersed particle mixing method, the present invention can quickly and accurately etch the lattice structure in the optical fiber core, thereby greatly improving the processing efficiency of the optical fiber and simplifying the manufacturing process. The present invention avoids the problem of proportioning and processing complexity of dispersed particles, and realizes the integrated design of the structure through laser micromachining technology, making the manufacturing process simpler, more stable, and reducing the difficulty and cost of production. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the structure of a columnar side-emitting optical fiber diffuser proposed by the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the front section of the diffuse core, the middle section of the diffuse core, and the rear section of the diffuse core cut in the diffuse core in an embodiment of the present invention.
[0018] The numbers in the figure are: 1. optical fiber connector; 2. optical fiber coating layer; 3. optical fiber cladding; 4. optical fiber core; 5. diffuse fiber core; 6. transmission optical fiber; 201. diffuse fiber core front section; 202. diffuse fiber core middle section; 203. diffuse fiber core back section. DETAILED DESCRIPTION
[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.
[0020] Reference Figure 1This embodiment proposes a columnar side-emitting optical fiber diffuser, whose structure mainly includes an optical fiber connector 1, a transmission optical fiber 6 and a diffuse fiber core 5. One end of the transmission optical fiber 6 is connected to the optical fiber connector 1, and the other end is connected to the diffuse fiber core 5. The optical fiber connector 1 in this embodiment is preferably an optical fiber connector with a model of SMA905 to ensure that the optical signal is smoothly transmitted from the transmission optical fiber 6 to the diffuse fiber core 5. The transmission optical fiber 6 includes an optical fiber coating layer 2, an optical fiber cladding 3 and an optical fiber core 4. The outer surface of the optical fiber core 4 is coated with the optical fiber cladding 3 and the optical fiber coating 2 in sequence. The outer surface of the diffuse fiber core 5 is coated with a sapphire powder layer, an optical fiber cladding 3 and an optical fiber coating 2 in sequence. The diffuse fiber core 5 is connected to one end of the optical fiber core 4. A lattice structure is etched inside the core of the diffuse fiber core 5 by a femtosecond laser. The aperture of the lattice structure gradually increases from the front section to the rear section, the spacing between the holes gradually decreases, and the number of holes gradually increases. The aperture of the lattice structure is micrometer-level and is formed by femtosecond laser etching to ensure high-precision light scattering. The lattice structure can evenly scatter the light signal to the side of the optical fiber, thereby ensuring the uniformity of the output light.
[0021] In order to show the change of the lattice structure, in this embodiment, the diffuse core is divided into a diffuse core front section 201, a diffuse core middle section 202 and a diffuse core rear section 203. The three cross-sectional structures are shown in FIG. Figure 2 As shown, the diffuse core front section 201 is located at the front section close to the connection between the diffuse core 5 and the transmission optical fiber 6, and the diffuse core front section 201 is followed by the diffuse core middle section 202 and the diffuse core rear section 203.
[0022] In the front section 201 of the diffuse core, the holes in the lattice structure have a smaller aperture, a larger spacing, and a smaller number to maintain an appropriate light scattering intensity, which is suitable for processing high-power lasers; in the middle section 202 of the diffuse core, the holes in the lattice structure have an increased aperture and density to adapt to the gradual attenuation of optical power and ensure uniform scattering of optical signals; in the rear section 203 of the diffuse core, the lattice structure has the largest aperture, the smallest spacing, and the largest number to compensate for the significant attenuation of optical power and ensure uniform light output at the end of the core. This lattice structure design effectively compensates for the attenuation of optical power and ensures uniform side light output.
[0023] In another implementation scenario of this embodiment, a method for manufacturing the above-mentioned columnar side-emitting optical fiber diffuser is also proposed, and the method comprises the following steps: Step 1, select a transmission optical fiber 6 having a structure of an optical fiber coating layer 2, an optical fiber cladding layer 3 and an optical fiber core 4, connect one end of the transmission optical fiber 6 to the optical fiber connector 1, and remove the optical fiber coating layer 2 and the optical fiber cladding layer 3 at the other end to expose the optical fiber core 4. One end of the transmission optical fiber 6 (the end where the optical fiber coating layer 2 and the optical fiber cladding layer 3 are not removed) is connected to the optical fiber connector 1, and it is best to use an optical fiber connector of model SMA905 to ensure smooth connection between the optical fiber and the external light source.
[0024] Step 2, fix the optical fiber core 4 on a glass slide, and place the glass slide on a three-dimensional electric translation stage. Set the repetition frequency, pulse width, and laser power of the femtosecond laser; focus the femtosecond laser near the optical fiber core through a microscope objective, perform femtosecond laser etching on the optical fiber core 4 on the glass slide, and etch a lattice structure on the optical fiber core 4 to form a diffuse core 5.
[0025] When performing femtosecond laser etching operation on the optical fiber core 4 on the glass slide, the repetition frequency of the femtosecond laser is 1000 Hz, the pulse width is 50 femtoseconds, the pulse duration of the femtosecond laser is in the range of 10 seconds to 1000 femtoseconds, the laser power is 0.7 mW, and a microscope objective lens with a magnification of 20 times and a numerical aperture of 0.45 is selected to achieve high-precision lattice structure etching.
[0026] The diffuse core 5 formed by etching a lattice structure on the optical fiber core 4 with a femtosecond laser is divided into a diffuse core front section 201, a diffuse core middle section 202 and a diffuse core back section 203; from the diffuse core front section 201 to the diffuse core middle section 202 and then to the diffuse core back section 203, the aperture of the holes on the etched lattice structure gradually increases, the spacing between the holes gradually decreases, and the number of holes gradually increases.
[0027] Diffuse core front section 201: The fiber section close to the transmission optical fiber 6 is etched with a smaller aperture, a larger hole spacing and a smaller number of holes to appropriately control the light scattering intensity and prevent excessive light loss.
[0028] The diffuse fiber core middle section 202: gradually increases the aperture, reduces the hole spacing and increases the number of holes to compensate for the attenuation of the optical power and ensure that the optical signal can be continuously and evenly scattered.
[0029] Dispersed core rear section 203: Etch the largest aperture, the smallest hole spacing and the largest number of holes to enhance the light scattering at the end, compensate for the optical power attenuation of the last part, and ensure uniform light output at the end of the optical fiber.
[0030] In this step, the aperture, spacing and number of the lattice structure can be optimized and designed by optical simulation, wherein the diffuse optical fiber can be divided into N sections according to the length to ensure that the optical power distribution of the fiber core is uniform over the entire length range.
[0031] Step 3, after completing the femtosecond laser etching, the diffuse fiber core 5 is cleaned to remove the tiny debris and residues generated during the processing to ensure the optical performance and the overall quality of the optical fiber.
[0032] Step 4: immerse the dispersed fiber core 5 in a frosting solution prepared by mixing frosting powder and hydrochloric acid in a certain proportion for roughening treatment. In this embodiment, the weight ratio of frosting powder to hydrochloric acid in the prepared frosting solution is preferably 3:1.
[0033] Step 5, after the dispersed core 5 is roughened, sapphire powder is coated on the outer surface of the dispersed core 5 to enhance the side-emitting performance. Preferably, the sapphire powder is firmly attached to the surface of the dispersed core 5 using epoxy optical glue of the model name Epo-Tek301, and then the optical fiber cladding 3 and the optical fiber coating layer 2 are sequentially coated on the sapphire powder layer.
[0034] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A method for manufacturing a columnar side-emitting optical fiber diffuser, characterized in that: The following steps are involved: Step 1, selecting a transmission optical fiber (6) having an optical fiber coating layer (2), an optical fiber cladding (3) and an optical fiber core (4) structure, connecting one end of the transmission optical fiber (6) to an optical fiber connector (1), and removing the optical fiber coating layer (2) and the optical fiber cladding (3) from the other end to expose a portion of the optical fiber core (4); Step 2, fixing the optical fiber core (4) on a glass slide, placing the glass slide on a three-dimensional electric translation stage, focusing a femtosecond laser near the optical fiber core (4) through a microscope objective, performing a femtosecond laser etching operation on the optical fiber core (4) on the glass slide, and etching a lattice structure on the optical fiber core (4) to form a diffuse core (5); Step 3, after completing the femtosecond laser etching, the diffuse fiber core (5) is cleaned to remove tiny debris and residues generated during the processing; Step 4, immersing the dispersed fiber core (5) in a frosting solution prepared by mixing frosting powder and hydrochloric acid in a certain proportion to perform a roughening treatment; Step 5: After the dispersed fiber core (5) is roughened, sapphire powder is coated on the outer surface of the dispersed fiber core (5).
2. A method for manufacturing a columnar side-emitting optical fiber diffuser according to claim 1, characterized in that: In step 1, the optical fiber connector (1) connected to one end of the transmission optical fiber (6) is a SMA905 optical fiber connector.
3. A method for manufacturing a columnar side-emitting optical fiber diffuser according to claim 1, characterized in that: In step 2, when the optical fiber core (4) on the glass slide is subjected to a femtosecond laser etching operation, the repetition frequency of the femtosecond laser is 1000 Hz, the pulse width is 50 femtoseconds, the pulse duration of the femtosecond laser is in the range of 10 seconds to 1000 femtoseconds, the laser power is 0.7 mW, and the microscope objective lens is selected with a magnification of 20 times and a numerical aperture of 0.
45.
4. A method for manufacturing a columnar side-emitting optical fiber diffuser according to claim 1, characterized in that: In step 2, a diffuse core (5) is formed after a lattice structure is etched on an optical fiber core (4) using a femtosecond laser. The diffuse core (5) is divided into a diffuse core front section (201), a diffuse core middle section (202) and a diffuse core rear section (203). From the diffuse core front section (201) to the diffuse core middle section (202) and then to the diffuse core rear section (203), the aperture of the holes on the etched lattice structure gradually increases, the spacing between the holes gradually decreases, and the number of holes gradually increases.
5. A method for manufacturing a columnar side-emitting optical fiber diffuser according to claim 1, characterized in that: In step 4, the weight ratio of frosting powder to hydrochloric acid in the prepared frosting solution is 3:
1.
6. A method for manufacturing a columnar side-emitting optical fiber diffuser according to claim 1, characterized in that: In step 5, the sapphire powder is firmly attached to the surface of the diffused fiber core (5) using epoxy optical glue of model name Epo-Tek301.
7. A columnar side-emitting optical fiber diffuser, manufactured by the method for manufacturing a columnar side-emitting optical fiber diffuser according to any one of claims 1 to 6, characterized in that: The invention comprises an optical fiber connector (1), a transmission optical fiber (6) and a diffuse fiber core (5), wherein the transmission optical fiber (6) comprises an optical fiber coating layer (2), an optical fiber cladding (3) and an optical fiber core (4), wherein the outer surface of the optical fiber core (4) is coated with the optical fiber cladding (3) and the optical fiber coating layer (2) in sequence, and the diffuse fiber core (5) is connected to one end of the optical fiber core (4). A lattice structure is etched inside the core of the diffuse fiber core (5) by a femtosecond laser, wherein the aperture of the lattice structure gradually increases from the front section to the rear section, the spacing between the holes gradually decreases, and the number of holes gradually increases.
8. A columnar side-emitting optical fiber diffuser according to claim 7, characterized in that: One end of the transmission optical fiber (6) is connected to the optical fiber connector (1), and the other end is connected to the diffuse fiber core (5).
9. A columnar side-emitting optical fiber diffuser according to claim 7, characterized in that: The outer surface of the dispersed fiber core (5) is sequentially coated with a sapphire powder layer, an optical fiber cladding layer (3) and an optical fiber coating layer (2).
10. A columnar side-emitting optical fiber diffuser according to claim 7 or 8, characterized in that: The optical fiber connector (1) is a SMA905 optical fiber connector.