An anti-resonant fiber optimization design method and system for infrared waveband transmission
By constructing a five-tube nested hollow anti-resonant fiber model and performing staged parameterized scanning, the matching relationship between the fiber core and the nested cladding tubes was optimized, solving the problem of difficulty in balancing confinement loss and bending loss in the 808nm band of hollow anti-resonant fiber, and realizing a fiber design with low loss and high efficiency.
Patent Information
- Application Number
- CN202610538308.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-22
- Publication Date
- 2026-07-10
AI Technical Summary
Existing hollow-core antiresonant optical fibers have difficulty simultaneously optimizing confinement loss and bending loss in the 808nm infrared band, resulting in poor transmission performance.
By constructing a hollow anti-resonant fiber model with a five-tube nested structure, key structural parameters were determined, and staged parameterized scanning was used for collaborative optimization. The matching relationship between the fiber core and the nested cladding tubes was optimized to select the optimal combination of structural parameters.
It achieves a balance between ultra-low confinement loss and low bending loss in the 808nm band, improving the bending resistance of optical fibers and the transmission efficiency of high-power lasers, making it suitable for lasers and optical communications.
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Figure CN122362659A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the fields of optical fiber communication technology, optics and laser optoelectronics technology, etc., and more specifically, relates to an anti-resonant optical fiber optimization design method and system for infrared band transmission. Background Technology
[0002] Hollow-core antiresonant optical fibers, by introducing periodic or nested microstructures into the cladding, utilize the antiresonance effect to confine the optical field within the air core for transmission, thereby significantly reducing material absorption and scattering losses. This demonstrates significant potential in fields such as infrared transmission and high-power laser delivery.
[0003] To improve performance, various cladding structures have been developed in existing technologies. Among them, hollow antiresonant optical fibers with negative curvature and nested cladding tubes (such as five-tube nested structures) further suppress optical field leakage and reduce fiber confinement loss by increasing the number of antiresonant interface layers.
[0004] However, in specific infrared bands such as 808nm, the loss performance of this type of fiber still faces significant challenges. Experiments and simulations show that confinement loss and bending loss are often difficult to balance: increasing the core diameter can reduce confinement loss, but it will significantly degrade bending performance and may exacerbate mode coupling; while improper matching of the size, wall thickness, and gap between the nested cladding tube and the core will lead to insufficient anti-resonance effect and increased light leakage, failing to realize the low-loss advantage that this structure should have.
[0005] Therefore, to achieve high-performance transmission in the 808nm band, there is an urgent need for a design method that can synergistically optimize confinement loss and bending loss. By finely controlling the matching relationship between the fiber core and the nested cladding tube, low confinement loss can be obtained while maintaining good bending performance. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides an anti-resonant optical fiber optimization design method and system for infrared band transmission.
[0007] The present invention adopts the following technical solution.
[0008] The first aspect of this invention provides an optimized design method for anti-resonant optical fibers used in infrared band transmission, comprising the following steps: A hollow anti-resonant fiber model with a five-tube nested structure is constructed for the coordinated optimization of limiting loss and bending loss in the target infrared band. A set of interrelated key structural parameters were determined, including the core radius, the large circle radius of the nested cladding tube, the small circle radius of the nested cladding tube, the large circle wall thickness, and the small circle wall thickness. The theoretical range of wall thickness for the large and small circles is determined based on the principle of anti-resonance optics, and the common feasible region of all key structural parameters is determined in combination with the constraints of the fabrication process. Within the common feasible domain, collaborative optimization is carried out through staged parameterized scanning. First, a coarse scan is used to determine the subspace of optimization parameters, and then a fine scan is used to select the optimal combination of structural parameters that meets the preset loss threshold within the subspace. Output the optimal combination of structural parameters.
[0009] Optionally, the steps for constructing a hollow-core anti-resonant fiber model include: Determine the performance parameters that need to be optimized in the target infrared band and their quantification standards; A five-tube nested anti-resonant fiber was selected as the initial structural model.
[0010] Optionally, determining the common feasible region includes: To meet the preset bending loss requirement as the initial constraint, the core radius is selected as the dominant parameter, and its initial value range is determined. Based on the rule of matching the magnitude of the major circle radius of the nested cladding tube with that of the fiber core, the relevant range of values for the major circle radius of the nested cladding tube is determined; Based on the determined core radius and the large circle radius of the nested cladding tube, the range of values for the small circle radius of the nested cladding tube is set for mode modulation and refinement of anti-resonance conditions. The theoretical range of the wall thickness of the large circle and the small circle is calculated based on the principle of anti-resonance optics. The theoretical range is then corrected by considering the constraints of the fabrication process, resulting in the corrected range of the wall thickness of the large circle and the small circle. The common feasible region is formed by combining the value ranges of the aforementioned key structural parameters. Optionally, the phased parameterized scan includes: The first round of scanning is performed. Within the common feasible region, multiple key structural parameters are scanned at a low resolution in the order of fiber core radius, large circle radius of nested cladding tube, small circle radius of nested cladding tube, large circle wall thickness and small circle wall thickness with a first preset step size. This is to screen out parameter subspaces that allow both fiber confinement loss and bending loss to reach the preliminary threshold. The second round of scanning is performed. Within the parameter subspace, the same parameter adjustment order as the first round of scanning is used. The key structural parameters are adjusted at high resolution with a second preset step size. The offset of the wall thickness of the large circle and the wall thickness of the small circle near the theoretical anti-resonance value is optimized to select the optimal combination of structural parameters that simultaneously meets the preset limit loss threshold and bending loss threshold. The second preset step size is smaller than the first preset step size. Optionally, the target infrared band has a wavelength of 808nm. The preset loss threshold includes the limiting loss and bending loss of the fiber fundamental mode.
[0011] The second aspect of the present invention provides a low-loss anti-resonant optical fiber for infrared band transmission, which is fabricated using the optimal combination of structural parameters determined by the anti-resonant optical fiber optimization design method for infrared band transmission as described in the first aspect of the present invention.
[0012] A third aspect of the present invention provides an anti-resonant fiber optimization design system for infrared band transmission, used to implement the anti-resonant fiber optimization design method for infrared band transmission described in the first aspect of the present invention, comprising: The module comprises a parameter setting module, a parameter determination module, a constraint management module, a collaborative optimization module, and a result output module, among which: The parameter setting module is used to construct a hollow anti-resonant fiber model with a five-tube nested structure; The parameter determination module is used to determine a set of key structural parameters; The constraint management module is used to determine the common feasible region based on anti-resonance conditions and process constraints; The collaborative optimization module is used to perform phased parametric scans within a common feasible domain; The results output module is used to output the optimal combination of structural parameters.
[0013] Optionally, the collaborative optimization module is used for: The first round of scanning is performed. Within the common feasible region, multiple key structural parameters are scanned at a low resolution in the order of fiber core radius, large circle radius of nested cladding tube, small circle radius of nested cladding tube, large circle wall thickness and small circle wall thickness with a first preset step size. This is to screen out parameter subspaces that allow both fiber confinement loss and bending loss to reach the preliminary threshold. The second round of scanning is performed. Within the parameter subspace, the same parameter adjustment order as the first round of scanning is used. The key structural parameters are adjusted at high resolution with a second preset step size. The offset of the wall thickness of the large circle and the wall thickness of the small circle near the theoretical anti-resonance value is optimized to select the optimal combination of structural parameters that simultaneously meets the preset limit loss threshold and bending loss threshold. Wherein, the second preset step size is smaller than the first preset step size. A fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When executed by the processor, the computer program implements an anti-resonant optical fiber optimization design method for infrared band transmission as described in the first aspect of the present invention.
[0014] The fifth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements an anti-resonant optical fiber optimization design method for infrared band transmission as described in the first aspect of the present invention.
[0015] Compared with the prior art, the beneficial effects of the present invention include: 1. This invention solves the problem of difficulty in balancing confinement loss and bending loss in the 808nm infrared band by constructing a size matching relationship between the fiber core and the nested cladding tube and by using staged parametric scanning for collaborative optimization. It achieves both ultra-low confinement loss and low bending loss with a larger fiber core size.
[0016] 2. This invention significantly suppresses mode leakage and coupling by refining the key parameters (such as wall thickness and radius) of the five-tube nested structure based on anti-resonance conditions, enabling the optical fiber to exhibit excellent bending resistance in the 808nm band, for example, bending loss is less than 0.2dB / km at a bending radius of 10cm.
[0017] 3. This invention reduces the nonlinear effect of optical fiber by optimizing structural parameters, thereby improving the efficiency and stability of high-power laser transmission in the 808nm band, and providing a high-performance, low-loss transmission medium for applications such as lasers and optical communications.
[0018] 4. While ensuring a significant improvement in infrared band transmission performance, this invention maintains a relatively simple structure. All key parameters are within the feasible range of existing processes, giving the optical fiber design good stretchability and industrialization potential. Attached Figure Description
[0019] Figure 1 This is a flowchart of a method provided according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of a low-loss anti-resonant optical fiber for high-performance transmission in the infrared band according to the present invention. Figure 3 This is the curve showing the relationship between the limiting loss of the fundamental mode and the wavelength in an embodiment of the present invention; Figure 4 This is the curve showing the relationship between the bending loss and the bending radius of the fundamental mode at a wavelength of 808nm in an embodiment of the present invention. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.
[0021] In Embodiment 1, this invention provides an optimized design method for anti-resonant optical fibers used in infrared band transmission, such as... Figure 1 As shown, it includes the following steps: Step 1: Construct a hollow anti-resonant fiber model for co-optimizing limiting loss and bending loss in the target infrared band. This hollow anti-resonant fiber model has a five-tube nested structure.
[0022] Preferably, step 1 includes: Step 1.1, Determine the core performance indicators and target values: Based on the application scenarios of optical fiber in the 808nm band, clarify the performance parameters that need to be optimized and their quantitative standards.
[0023] For example, the specific target is set as follows: at an operating wavelength of 808nm, the confinement loss of the fiber fundamental mode is less than 0.01dB / km; at the same time, at a bending radius of 10cm, the bending loss is less than 0.2dB / km.
[0024] Step 1.2, Selecting the Initial Optimized Structure: Considering both structural stability and technological feasibility, a five-tube nested anti-resonant fiber was selected as the initial structural model. This model has five uniformly arranged nested cladding tubes, each consisting of a larger circular cladding tube and a smaller circular cladding tube, with one side of its tube wall connected to the outer structure.
[0025] Specifically, to ensure the accuracy of the parametric scanning direction, two basic tasks need to be completed first: Determine core performance indicators and target values: Based on the application scenarios of optical fiber (such as laser transmission, sensing, etc.), identify the key performance parameters that need to be optimized and their quantification standards. Taking 808nm band applications as an example, the core indicators can be set as follows: at an 808nm operating wavelength, the fundamental mode confinement loss (CL) of the optical fiber must be less than 0.01dB / km (ensuring low-loss long-distance transmission of optical signals); simultaneously, in practical application scenarios with a 10cm bending radius, the bending loss (BL) must be less than 0.2dB / km (meeting the requirements for flexible deployment). Defining these target values provides a basis for subsequent parameter optimization.
[0026] Initial optimized structure selected: Considering structural stability, fabrication feasibility, and anti-resonance characteristics, a five-tube nested anti-resonant fiber was chosen as the initial structure. This nested design allows for flexible adjustment of the optical field confinement capability by modifying the cladding tube parameters, making it a suitable basic model for achieving low-loss goals.
[0027] Step 2: Select a set of interrelated key structural parameters to be optimized, including the core radius, the large circle radius of the nested cladding tube, the small circle radius of the nested tube, the wall thickness of the large circle, and the wall thickness of the small circle.
[0028] Specifically, the radius of the outer circular tube and the radius of the air fiber core are set to have a geometric relationship; Step 2.1, Identify key design parameters: Determine the key structural parameters that affect performance indicators, including the core radius R, the radius r1 of the large circle of the nested cladding tube, the radius r2 of the small circle of the nested tube, the wall thickness t1 of the large circle, and the wall thickness t2 of the small circle.
[0029] Step 2.2, establish the initial constraint relationship between parameters: set the large circle radius r1 of the nested cladding tube and the core radius R to have geometric correlation, that is, the two dimensions need to match. Generally, r1 increases as R increases, so as to effectively control the gap of the cladding tube and suppress light leakage while expanding the core to reduce confinement loss.
[0030] Specifically, the confinement loss of current antiresonant optical fibers is mainly affected by the core radius R. Generally, a larger core radius R results in lower confinement loss, but a larger core radius leads to poorer bending resistance. Nested large and small cladding tubes in the fiber influence overall performance in two ways: firstly, multiple antiresonant cladding tubes can introduce multiple antiresonant reflections, allowing light to be better confined within the core; secondly, in terms of coupling, multiple cladding tubes can suppress mode coupling, improving both confinement and bending loss performance. The radii r1 and r2 of the two cladding tubes primarily reduce the gap between them, decreasing light leakage and thus improving overall performance. The cladding thickness t is mainly to meet the antiresonant reflection condition in principle; if it is too small or too large, the fiber will lose its light confinement function.
[0031] The core radius should not be too small, but too large a radius will affect the bending loss performance of the optical fiber. An appropriately large core radius should be selected, and a suitable size should be obtained through simulation by controlling the cladding tube gap. Generally, r1 and r2 will increase as R increases, and the optimal range of t should be determined through simulation.
[0032] Step 3: Determine the theoretical range of wall thickness for each circular tube based on the principle of anti-resonance optics, and determine the common feasible domain of all the key structural parameters in combination with the constraints of the fabrication process.
[0033] Preferably, determining the common feasible region includes: To meet the preset bending loss requirement as the initial constraint, the core radius is selected as the dominant parameter, and its initial value range is determined. Based on the rule of matching the magnitude of the major circle radius of the nested cladding tube with that of the fiber core, the relevant range of values for the major circle radius of the nested cladding tube is determined; Based on the determined core radius and the large circle radius of the nested cladding tube, the range of values for the small circle radius of the nested cladding tube is set for mode modulation and refinement of anti-resonance conditions. The theoretical range of the wall thickness of the large circle and the small circle is calculated based on the principle of anti-resonance optics. The theoretical range is then corrected by considering the constraints of the fabrication process, resulting in the corrected range of the wall thickness of the large circle and the small circle. The common feasible region is formed by combining the value ranges of the above key structural parameters.
[0034] Specifically, step 3 includes: Step 3.1: Using the core radius R as the dominant parameter, set the initial value according to the bending loss constraint.
[0035] Specifically, to ensure that the bending loss is less than 0.2dB / km at the 808nm wavelength and a bending radius of 10cm, the initial value of the fiber core radius R is set to 25μm; The large circle radius r1 of the nested cladding tube is set to be on the same order of magnitude as the core radius R to achieve size matching and suppress light leakage; the small circle radius r2 of the nested tube is set according to the mode control requirements.
[0036] Step 3.2: Based on the determined geometric dimensions, calculate the theoretical range of the wall thickness t1 of the large circle and the wall thickness t2 of the small circle according to the anti-resonance condition formula:
[0037] In the formula, m is the anti-resonance order, which is a positive integer; n 0 is the effective refractive index of air. The effective refractive index of glass, t For glass thickness, λ λ is the wavelength.
[0038] Step 3.3: Based on the theoretical value range and combined with the current technological level in the field of anti-resonant fiber fabrication, determine the final common feasible domain of each parameter.
[0039] For example, the final common feasible domain includes: The air core radius R is 20μm to 150μm; the cladding tube radii r1 and r2 are 5μm to 60μm; and the cladding tube wall thicknesses t1 and t2 are 0.1μm to 0.6μm.
[0040] It should be noted that in this invention, the determination of key structural parameters is not carried out in isolation, but follows a comprehensive judgment principle of "taking the core radius as the main factor and taking into account bending loss and anti-resonance conditions".
[0041] First, the core radius (or equivalent core diameter) is used as the dominant parameter. This is because in antiresonant fibers, increasing the core radius significantly reduces confinement loss and is the main factor affecting overall transmission loss. However, the infinite increase in core radius is limited by bending loss. Therefore, in the initial design stage, this method uses a relatively large bending radius (approximately 25 μm) as the starting condition, selecting a relatively large core radius as the design starting point while ensuring acceptable bending loss.
[0042] Based on this, the equivalent radius of the outer large nested cladding tube was set to be on the same order of magnitude as the core radius. This design was not chosen arbitrarily, but rather based on engineering conclusions drawn from previous experiments and empirical tests: when the size of the large nested tube matches the core radius, the confinement loss can be effectively reduced without significantly introducing additional bending losses, thus obtaining an initial, representative low-loss baseline structure.
[0043] Subsequently, based on the previously determined core radius and large nested cladding tube size, a small nested cladding tube structure is introduced. Since loss limitation is mainly dominated by the core size, the introduction of the small nested cladding tube and its corresponding wall thickness will not significantly change the overall loss level by more than two orders of magnitude, but rather play a role in mode modulation and refining anti-resonance conditions.
[0044] The wall thickness parameter is first determined based on the target operating wavelength. The design wavelength is substituted into the anti-resonance condition formula to obtain the theoretical range of wall thickness values. Then, considering the process constraints on minimum wall thickness, structural stability, and forming consistency during fiber drawing, the upper and lower limits of this theoretical range are adjusted. Finally, under the premise of satisfying the anti-resonance condition and fabrication feasibility, the intersection of each structural parameter forms a common feasible region for multiple parameters.
[0045] Step 4: Within the common feasible domain, collaborative optimization is performed through phased parameterized scanning. First, a coarse scan is used to determine the optimization parameter subspace, and then a fine scan is used to select the optimal combination of structural parameters that meets the preset loss threshold within the subspace.
[0046] Preferably, the staged parametric scanning includes: The first round of scanning is performed, and multiple key structural parameters are adjusted in a coordinated manner with a first preset step size. The parameter adjustment order is based on the primary and secondary relationship of the parameters' impact on loss: first adjust the core radius, then adjust the large circle radius of the nested cladding tube, the small circle radius of the nested cladding tube, the wall thickness of the large circle and the wall thickness of the small circle in sequence, and identify the parameter subspace that meets the preliminary optimization target. The second round of scanning is performed. Within the parameter subspace, the same parameter adjustment order as the first round of scanning is used to finely adjust the key structural parameters with a second preset step size, and the optimal combination of structural parameters is selected. The second preset step size is smaller than the first preset step size.
[0047] It should be noted that, after determining the common feasible region, this invention adopts a phased parameterized scanning collaborative optimization strategy to improve the efficiency and stability of multidimensional structural parameter optimization.
[0048] During the coarse scan stage, adjust the parameters in the following order: 1) Core diameter; 2) Large nested cladding tube dimensions; 3) Small nested cladding tube dimensions; 4) Corresponding cladding wall thickness parameters.
[0049] This order reflects the primary and secondary relationship of parameter influence on loss. Core size and large nested structures preferentially determine the overall loss level, while small nested structures and wall thickness parameters are used to further satisfy anti-resonance conditions and mode optimization requirements. Through low-resolution joint scanning, parameter subspaces that meet preset loss thresholds are selected.
[0050] During the fine-scanning stage, within the aforementioned parameter subspace, the same parameter adjustment sequence is used to fine-tune each parameter at high resolution, focusing on optimizing the offset of the wall thickness near the theoretical anti-resonance value, thereby obtaining the optimal combination of structural parameters that comprehensively considers limiting losses, bending losses, and manufacturability.
[0051] Specifically, step 4 includes: Step 4.1: Using finite element simulation software (such as COMSOL Multiphysics), set scattering boundary conditions as port excitations, and set a perfect matching layer (PML) on the outermost layer.
[0052] Step 4.2: The simulation adopts a modal analysis method for the cross-section of the optical fiber. The glass part uses a meshing method with a maximum element size of λ / 5.8 (λ is the wavelength in vacuum), and the air part uses a meshing method with a maximum element size of λ / 4. A perfectly matched layer is added to the outermost layer to simulate an infinitely large silicon glass optical fiber jacket.
[0053] Step 4.3, perform a phased parametric scan, including: When using parametric scanning to find optimal parameters, it is necessary to first combine theoretical calculations with preliminary basic experiments to clarify the approximate range of core parameters such as cladding tube radius, quantity, and wall thickness, and then proceed with optimization in two orderly rounds: In the first round of scanning, multiple key structural parameters (such as cladding tube radius, quantity, and wall thickness) are adjusted collaboratively at a preset step size. Due to the large range of parameters and the simultaneous adjustment across multiple dimensions, simulation data (such as constraint loss and bending loss) change significantly, often showing differences of 1-2 orders of magnitude. By evaluating these significant changes in performance indicators, inefficient regions can be quickly eliminated, thereby identifying the parameter subspace that meets the initial optimization objectives.
[0054] The second round of scanning enters the fine-tuning stage: within the parameter subspace determined by the first round of scanning, key structural parameters are fine-tuned with a second preset step size. At this stage, parameters such as the number of cladding tubes can be fixed, and the focus is on adjusting the wall thickness and radius with small steps. Because the adjustment dimensions are focused and the magnitude is reduced (the second preset step size is smaller than the first preset step size), data changes are usually limited to the same order of magnitude. Through multiple rounds of small-amplitude adaptation, the optimal combination of structural parameters that meets the preset loss threshold and takes into account process feasibility is finally selected.
[0055] The two scanning processes described above constitute a complete optimization loop. If necessary, the adjustment process of the first round can be repeated based on the results of the second round to confirm and iterate, ensuring the robustness of the optimization results.
[0056] Step 5: Output the optimal combination of structural parameters.
[0057] Preferably, step 5 includes: Step 5.1: From the optimal solution set obtained from the simulation, select a set of parameter combinations that satisfy all the preset performance target thresholds in Step 1.1 as the final design result.
[0058] Step 5.2 outputs a set of preferred parameter combinations, for example: R=19.5μm, r1=19.6μm, r2=13μm, t1=0.58μm, t2=0.59μm. This combination has been verified to have ultra-low confinement loss and low bending loss in the 808nm band.
[0059] The performance of this set of parameters is verified as follows: The present invention will be further described below with reference to a specific example, but the scope of protection of the present invention is not limited thereto.
[0060] Figure 2 This is a schematic diagram of the cross-sectional structure of a low-loss anti-resonant optical fiber for high-performance infrared transmission according to the present invention. In this embodiment, the structure of a low-loss anti-resonant optical fiber for high-performance infrared transmission is as follows. Figure 2As shown, from the outside in, the structure consists of outer structure 1, nested cladding tubes 2, and air core 3. Outer structure 1 is the outermost layer of the hollow anti-resonant fiber, enclosing various cladding tubes inside it. Nested cladding tubes 2 include a larger circular cladding tube and a smaller circular cladding tube, with the smaller nested tube inside the larger cladding tube. One side of each of the smaller nested tubes is connected to the outer structure, and the five are evenly connected to the outer structure. The air core 3 is formed by being surrounded by nested cladding tubes 2.
[0061] Specific parameters of the fiber core are as follows Figure 2 As shown, the core radius is R, the large circle radius of the nested cladding tube is r1, and the small circle radius of its nesting is r2.
[0062] The wall thickness of the large circle in the nested cladding tube is t1, and the wall thickness of the small circle is t2. For these parameters of the hollow-core anti-resonant fiber, the anti-resonance condition must be met. According to the principle of anti-resonance reflection, the phase difference of light is related to the wavelength λ and the glass thickness t, as shown in the following formula.
[0063] In the formula The effective refractive index of air, The effective refractive index of glass, t For glass thickness, λ The wavelength is specified. Only when parameters such as wall thickness and refractive index are within the appropriate range can light leakage be suppressed. Anti-resonant optical fibers do not have an absolute limitation on their core diameter. The suppression mode coupling theory addresses the ratio of the cladding tube radius to the core radius, and the core diameter largely determines the magnitude of the loss limitation. Therefore, the core diameter of the anti-resonant optical fiber must be flexibly and appropriately adjusted to achieve the desired performance goals.
[0064] Under normal circumstances, doubling the core diameter reduces confinement loss by about 1-1.5 orders of magnitude, but LP 01 Model and LP 11 While the confinement loss of the mode will decrease simultaneously, the loss performance of the anti-resonant fiber at small bending radii will be severely impaired as the core diameter increases, and breakage may occur during actual use. Therefore, it is necessary to fully consider the confinement loss and bending loss performance of the fiber, reasonably adjust the size of the core radius, and make trade-offs to obtain excellent performance. The above example has a large core diameter and takes bending loss into account in the simulation, thereby effectively reducing the confinement loss.
[0065] In Embodiment 2, this invention provides an anti-resonant fiber optimization design system for infrared band transmission, used to implement the anti-resonant fiber optimization design method for infrared band transmission described in Embodiment 1, comprising: The module comprises a parameter setting module, a parameter determination module, a constraint management module, a collaborative optimization module, and a result output module, among which: The parameter setting module is used to construct a hollow anti-resonant fiber model with a five-tube nested structure; The parameter determination module is used to determine a set of key structural parameters; The constraint management module is used to determine the common feasible region based on anti-resonance conditions and process constraints; The collaborative optimization module is used to perform phased parametric scans within a common feasible domain; The results output module is used to output the optimal combination of structural parameters.
[0066] Preferably, the collaborative optimization module is used for: The first round of scanning is performed. Within the common feasible region, multiple key structural parameters are scanned at a low resolution in the order of fiber core radius, large circle radius of nested cladding tube, small circle radius of nested cladding tube, large circle wall thickness and small circle wall thickness with a first preset step size. This is to screen out parameter subspaces that allow both fiber confinement loss and bending loss to reach the preliminary threshold. The second round of scanning is performed. Within the parameter subspace, the same parameter adjustment order as the first round of scanning is used. The key structural parameters are adjusted at high resolution with a second preset step size. The offset of the wall thickness of the large circle and the wall thickness of the small circle near the theoretical anti-resonance value is optimized to select the optimal combination of structural parameters that simultaneously meets the preset limit loss threshold and bending loss threshold. Wherein, the second preset step size is smaller than the first preset step size. Embodiment 3 of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded onto the processor, it implements an anti-resonant optical fiber optimization design method for infrared band transmission as described in Embodiment 1.
[0067] Embodiment 4 of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements an anti-resonant optical fiber optimization design method for infrared band transmission as described in Embodiment 1.
[0068] In Embodiment 5, this invention provides a method for designing an anti-resonant optical fiber for infrared band transmission, used to manufacture the anti-resonant optical fiber for infrared band transmission described in Embodiment 1. The method includes: In this example, the corresponding parameters are R=19.5μm, r1=19.6μm, r2=13μm, t1=0.58μm, t2=0.59μm, where the refractive index of the material used is 1.45, and the refractive index of air is 1. This embodiment was simulated using the finite element simulation software Comsol Multiphysics. The simulation employed modal analysis of the fiber cross-section. The glass portion used a mesh size of λ / 5.8 (λ being the wavelength in vacuum), while the air portion used a mesh size of λ / 4. A perfectly matched layer was added to the outermost layer to simulate an infinitely large silicon glass fiber liner.
[0069] Confinement loss (CL) is one of the main factors affecting the performance of hollow-core antiresonant optical fibers. It is a theoretically unavoidable loss in optical fibers. Its calculation formula is as follows:
[0070] in, λ Wavelength, unit: m , For effective refractive index, The imaginary part of the effective refractive index, CL, is expressed in dB / km.
[0071] In COMSL, this formula is used for calculation. After completing fiber modeling, mode analysis will yield the fiber's mode field distribution. The imaginary part of the fiber's effective refractive index is extracted and substituted into the above formula for calculation. Note that the obtained effective refractive index is a complex number, which is required... It is the virtual representation of the effective refractive index. This allows for the simulation of limited losses.
[0072] The measured limit loss in this example was below 0.2 dB / km between 640 and 1000 nm, with the lowest measured at 0.00267 dB / km at 800 nm. Furthermore, the limit loss remained between 0.1 dB / km and 0.001 dB / km between 640 and 1000 nm. Figure 3 As shown.
[0073] Bending loss (BL) is also one of the main factors affecting hollow-core antiresonant fibers. When the fiber bends, the inner layer is compressed while the outer layer is stretched, causing a change in the fiber's mode field distribution. This leads to a change in the effective refractive index and coupling with the core modes, increasing leakage and causing much energy to escape beyond the cladding. In calculations, an equivalent method must be used, treating the bent fiber as a straight fiber. This method allows the refractive index to be equivalently represented by the following formula during bending.
[0074] in, This represents the refractive index distribution of the original optical fiber. x This is the equivalent straight fiber distance from the center point of the fiber core. Rc This represents the bending radius of the optical fiber. After conformal transformation, the effective refractive index is obtained, and its imaginary part is taken. Substituting this into the previously defined loss formula yields the bending loss of the optical fiber. Simultaneously, in this example, the bending loss as a function of the bending radius was measured at 808nm. The bending loss decreased from 0.90dB / km at a bending radius of 8cm to 0.00503dB / km at 40cm. Figure 4 As shown.
[0075] The simulation results above demonstrate that the optical fiber structure designed in this invention exhibits excellent transmission performance in both the 808nm target band and the wide spectral range, specifically in the following aspects: Firstly, regarding loss performance, by adopting a design that matches the dimensions of the fiber core and the nested cladding tube, and through staged parametric scanning and collaborative optimization, this invention effectively prevents light leakage while maintaining a relatively large fiber core diameter (R=19.5μm) to achieve low confinement loss, and also ensures excellent bending resistance. Simulation verification shows that the confinement loss of this optical fiber is less than 0.2dB / km in a wide wavelength range of 640-1000nm, with the lowest reaching 0.00267dB / km at 800nm. It also meets the ultra-low loss transmission requirements (less than 0.01dB / km) in the target 808nm band. Bending loss is particularly outstanding at 808nm wavelength, reaching only 0.16697dB / km with a bending radius of 10cm, and further decreasing to 0.00503dB / km at 40cm, demonstrating its stability in bending scenarios during practical deployment.
[0076] Secondly, regarding transmission characteristics, addressing the significant nonlinear effects of single-mode fibers in high-power transmission in the 808nm band, this invention effectively suppresses mode coupling and optical leakage through optimized structure, thereby reducing nonlinear effects. This makes the fiber model not only low-loss but also provides a more efficient and stable energy transmission solution for high-power lasers and precision optical communication systems, broadening its potential in high-end laser applications.
[0077] Finally, in terms of process implementation, all key structural parameters of this invention (such as wall thicknesses t1 and t2 in the submicron range, and radii R, r1, and r2 in the tens of micrometer range) are set within the feasible range of current mainstream anti-resonant fiber fabrication processes (such as capillary stacking and drawing techniques). While achieving significant performance improvements, the structure maintains a relatively simple five-tube nested form without overly complex microstructures, thus possessing high drawability and repeatability, which is beneficial for reducing production costs and promoting industrialization. This optical fiber has promising application prospects in optical communication, laser transmission, and sensing.
[0078] The above description of specific illustrative embodiments of the present invention is provided to enable those skilled in the art to understand the invention. However, the invention is not limited to these embodiments. Various modifications and variations are possible for those skilled in the art. All inventions, improvements, substitutions, and other creations utilizing the concept of the present invention are within the scope of protection.
[0079] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.
[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.
Claims
1. A method for optimizing the design of anti-resonant optical fibers for infrared band transmission, characterized in that, Includes the following steps: A hollow anti-resonant fiber model with a five-tube nested structure is constructed for the coordinated optimization of limiting loss and bending loss in the target infrared band. Select a set of interrelated key structural parameters to be optimized, including core radius, large circle radius of nested cladding tube, small circle radius of nested cladding tube, large circle wall thickness, and small circle wall thickness; The theoretical range of wall thickness for the large and small circles is determined based on the principle of anti-resonance optics, and the common feasible region of all key structural parameters is determined in combination with the constraints of the fabrication process. Within the common feasible domain, collaborative optimization is carried out through staged parameterized scanning. First, a coarse scan is used to determine the subspace of optimization parameters, and then a fine scan is used to select the optimal combination of structural parameters that meets the preset loss threshold within the subspace. Output the optimal combination of structural parameters.
2. The anti-resonant optical fiber optimization design method for infrared band transmission according to claim 1, characterized in that: The steps for constructing a hollow anti-resonant fiber model include: Determine the performance parameters that need to be optimized in the target infrared band and their quantification standards; A five-tube nested anti-resonant fiber was selected as the initial structural model.
3. The anti-resonant optical fiber optimization design method for infrared band transmission according to claim 1, characterized in that: Determining the common feasible region includes: To meet the preset bending loss requirement as the initial constraint, the core radius is selected as the dominant parameter, and its initial value range is determined. Based on the rule of matching the magnitude of the major circle radius of the nested cladding tube with that of the fiber core, the relevant range of values for the major circle radius of the nested cladding tube is determined; Based on the determined core radius and the large circle radius of the nested cladding tube, the range of values for the small circle radius of the nested cladding tube is set for mode modulation and refinement of anti-resonance conditions. The theoretical range of the wall thickness of the large circle and the small circle is calculated based on the principle of anti-resonance optics. The theoretical range is then corrected by considering the constraints of the fabrication process, resulting in the corrected range of the wall thickness of the large circle and the small circle. The common feasible region is formed by combining the value ranges of the above key structural parameters.
4. The anti-resonant optical fiber optimization design method for infrared band transmission according to claim 1, characterized in that: Phased parametric scanning includes: The first round of scanning is performed. Within the common feasible region, multiple key structural parameters are scanned at a low resolution in the order of fiber core radius, large circle radius of nested cladding tube, small circle radius of nested cladding tube, large circle wall thickness and small circle wall thickness with a first preset step size. This is to screen out parameter subspaces that allow both fiber confinement loss and bending loss to reach the preliminary threshold. The second round of scanning is performed. Within the parameter subspace, the same parameter adjustment order as the first round of scanning is used. The key structural parameters are adjusted at high resolution with a second preset step size. The offset of the wall thickness of the large circle and the wall thickness of the small circle near the theoretical anti-resonance value is optimized to select the optimal combination of structural parameters that simultaneously meets the preset limit loss threshold and bending loss threshold. The second preset step size is smaller than the first preset step size.
5. The anti-resonant optical fiber optimization design method for infrared band transmission according to claim 1, characterized in that: The target's infrared wavelength is 808nm; The preset loss threshold includes the limiting loss and bending loss of the fiber fundamental mode.
6. A low-loss anti-resonant optical fiber for infrared band transmission, characterized in that, The fiber is prepared using the optimal combination of structural parameters determined by the anti-resonant fiber optimization design method for infrared band transmission as described in any one of claims 1-5.
7. An anti-resonant fiber optic optimization design system for infrared band transmission, used to implement the anti-resonant fiber optic optimization design method for infrared band transmission as described in any one of claims 1-5, characterized in that, include: The module comprises a parameter setting module, a parameter determination module, a constraint management module, a collaborative optimization module, and a result output module, among which: The parameter setting module is used to construct a hollow anti-resonant fiber model with a five-tube nested structure; The parameter determination module is used to determine a set of key structural parameters; The constraint management module is used to determine the common feasible region based on anti-resonance conditions and process constraints; The collaborative optimization module is used to perform phased parametric scans within a common feasible domain; The results output module is used to output the optimal combination of structural parameters.
8. The anti-resonant fiber optic optimization design system for infrared band transmission according to claim 7, characterized in that: The collaborative optimization module is used for: The first round of scanning is performed. Within the common feasible region, multiple key structural parameters are scanned at a low resolution in the order of fiber core radius, large circle radius of nested cladding tube, small circle radius of nested cladding tube, large circle wall thickness and small circle wall thickness with a first preset step size. This is to screen out parameter subspaces that allow both fiber confinement loss and bending loss to reach the preliminary threshold. The second round of scanning is performed. Within the parameter subspace, the same parameter adjustment order as the first round of scanning is used. The key structural parameters are adjusted at high resolution with a second preset step size. The offset of the wall thickness of the large circle and the wall thickness of the small circle near the theoretical anti-resonance value is optimized to select the optimal combination of structural parameters that simultaneously meets the preset limit loss threshold and bending loss threshold. The second preset step size is smaller than the first preset step size.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is executed by the processor, it implements an anti-resonant optical fiber optimization design method for infrared band transmission as described in any one of claims 1-5.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements an anti-resonant optical fiber optimization design method for infrared band transmission as described in any one of claims 1-5.