WO2021128563A1 - 抗弯多模光纤 - Google Patents

抗弯多模光纤 Download PDF

Info

Publication number
WO2021128563A1
WO2021128563A1 PCT/CN2020/076435 CN2020076435W WO2021128563A1 WO 2021128563 A1 WO2021128563 A1 WO 2021128563A1 CN 2020076435 W CN2020076435 W CN 2020076435W WO 2021128563 A1 WO2021128563 A1 WO 2021128563A1
Authority
WO
WIPO (PCT)
Prior art keywords
refractive index
layer
cladding layer
optical fiber
outer cladding
Prior art date
Application number
PCT/CN2020/076435
Other languages
English (en)
French (fr)
Inventor
蒋新力
许维维
沈一春
王见青
范艳层
徐希凯
Original Assignee
中天科技精密材料有限公司
江苏中天科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 中天科技精密材料有限公司, 江苏中天科技股份有限公司 filed Critical 中天科技精密材料有限公司
Publication of WO2021128563A1 publication Critical patent/WO2021128563A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/028—Optical fibres with cladding with or without a coating with core or cladding having graded refractive index
    • G02B6/0288—Multimode fibre, e.g. graded index core for compensating modal dispersion
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
    • G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
    • G02B6/03661—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 4 layers only

Definitions

  • the invention relates to the technical field of optical fibers, in particular to a bending-resistant multimode optical fiber.
  • Multimode fiber is widely used in medium and short-distance network systems, especially data centers, due to its low system cost and large transmission capacity.
  • FTTX the Internet of Things
  • cloud computing the cloud computing
  • cloud storage the amount of network data communication has shown an exponential increase, and the requirements for the transmission performance of multimode optical fibers have continued to increase.
  • large-scale LAN systems such as data centers and supercomputing centers
  • high-speed data transmission requires more optical fiber links in a limited space.
  • Optical fibers often experience varying degrees of bending, and high-order modes transmitted in multimode optical fibers are easy to transmit.
  • the commonly used method of reducing bending loss adopts the depressed layer design.
  • the high-order mode will be effectively restricted to the depressed layer when the fiber undergoes macrobending, thereby reducing the leakage of the high-order mode, thereby reducing the fiber bending loss.
  • the multimode fiber should have the widest possible bandwidth.
  • the fiber bandwidth can be "full injection” (only applicable to light sources with uniform emission in the radial direction) and "effective" Mode” is characterized in two ways, in which at least 24 continuous injections of the same light pulse of a given wavelength at different positions in the radial direction are used to obtain Dispersive Mode Delay (DMD) data.
  • DMD Dispersive Mode Delay
  • the mode dispersion can be measured and the effective mode can be calculated. bandwidth.
  • the greater the mode delay the higher the overlap ratio between adjacent pulses due to broadening, which reduces the transmission bandwidth of the optical fiber.
  • the refractive index profile of the core layer of the multimode fiber needs to be designed as a parabolic structure with a power exponential distribution, so that the bandwidth performance can be optimized by adjusting the core layer distribution index.
  • some higher-order modes cannot be completely confined in the core layer, and some are transmitted in the sink layer. Due to the abrupt refractive index at the core-clad (core layer and sink layer) boundary, the higher-order modes cannot be properly controlled.
  • the high-order mode at the boundary shows multiple pulses, which causes the signal response time to expand, the mode delay increases, and the bandwidth performance decreases.
  • This core-cladding interface effect has an impact on bandwidth, which is especially prominent in bending-insensitive multimode fibers.
  • the refractive index difference between the deep depressed layer and the core layer is large, and higher-order modes propagate faster or slower than other modes. Cause severe pulse distortion and affect bandwidth performance.
  • the difference in light composition is large, which leads to problems such as steam drum or high stress at the interface due to the large viscosity difference during the core rod production and drawing process, which affects the product. performance.
  • a platform layer is usually added to the core layer and the depressed layer to compensate the influence of the core-cladding interface effect on the higher-order modes, as shown in Fig. 1, where the refractive index of the platform layer is a fixed value. Equal to the refractive index at the interface between the platform layer and the core layer. However, because the refractive index difference between the platform layer and the depressed layer is still large, the discontinuity of the refractive index profile will still affect the transmission rate of high-order modes at the interface and affect the bandwidth performance of the multimode fiber.
  • a bending-resistant multimode optical fiber which includes a core layer and an inner cladding layer with a graded refractive index, and a depressed layer and an outer cladding layer with a step refractive index from the center of the optical fiber.
  • the refractive index of the core layer relative to the outer cladding layer presents an ⁇ -power exponential function distribution with the increase in radius, ⁇ is the refractive index profile distribution parameter of the core layer, the refractive index at the center of the core layer is the largest, and the depression The refractive index of the inner cladding layer is the smallest.
  • the refractive index of the inner cladding layer relative to the outer cladding layer starts from the refractive index of the outer boundary of the core layer relative to the outer cladding layer, and gradually decreases with the increase of the radius to control high-order modes. Transmission rate and bandwidth.
  • the refractive index of the inner cladding layer relative to the outer cladding layer presents an oblique straight line section or a curved section as the radius increases.
  • the refractive index of the inner cladding layer relative to the outer cladding layer is an oblique straight line segment with an increase in radius, and the angle of the oblique straight line rotating counterclockwise with respect to the horizontal direction of the starting point is less than 45°.
  • the refractive index of the inner cladding layer relative to the outer cladding layer forms a curved segment with an increase in radius, the end point of the curved segment rotates counterclockwise with respect to the horizontal direction of the starting point at an angle less than 45°, and the curved segment and The refractive index difference between the end points of the curve segment relative to the outer cladding layer gradually increases from zero as the radius increases, and then decreases to zero.
  • the refractive index distribution of the multimode optical fiber satisfies a first relational expression, and the first relational expression is:
  • n(r) is the refractive index at the radius r
  • ⁇ 0 is the relative refractive index difference between the center of the core layer and the inner boundary of the inner cladding layer.
  • R g is a layer of the core
  • n 1 is R g with respect to the outer cladding refractive index
  • n 2 is the R u with respect to the outer cladding refractive Rate
  • Ru is the outer diameter of the inner cladding and the inner diameter of the depressed layer
  • n 3 is a constant
  • n 3 is the refractive index of the depressed layer
  • n c is the refractive index of the outer cladding
  • R f is The outer diameter of the depressed layer and the inner diameter of the outer cladding layer
  • R max is the outer diameter of the outer cladding layer.
  • the refractive index of the center of the core layer relative to the outer cladding layer ranges from 0.013 to 0.016, and the ⁇ is from 1.90 to 2.10.
  • the range of the R g is 22-32 ⁇ m.
  • the range of the refractive index of the R g relative to the outer cladding layer is 0.0005 to 0.002; the range of the refractive index of the R u relative to the outer cladding layer is -0.0005 to 0.0005.
  • the width of the inner cladding layer is 3-5.5 ⁇ m.
  • the refractive index of the depressed layer relative to the outer cladding layer is -0.006 to -0.0025.
  • the width of the depressed layer is 2.5-5.5 ⁇ m.
  • the outer cladding layer is a silicon dioxide layer.
  • the outer diameter of the outer cladding layer is 62.5 ⁇ 2.5 ⁇ m.
  • the multimode optical fiber provided by the present invention is provided with an inner cladding layer with a continuously adjustable refractive index between the core layer and the depressed layer, so that the refractive index between the core layer and the depressed layer gradually transitions. Avoid the sudden change of the refractive index between the core layer and the depressed layer, thereby reducing the interference of the core-cladding boundary on the transmission rate of higher-order modes, so as to increase the fiber transmission bandwidth, and because of the continuous adjustable inner cladding profile design, it also reduces the viscosity difference. The impact of fiber performance.
  • FIG. 1 is a schematic diagram of a connection structure design of a core layer and a depressed layer in the prior art.
  • FIG. 2 is a schematic diagram of a cross-sectional structure of a bending-resistant multimode optical fiber provided by an embodiment of the present invention.
  • FIG. 3 is a schematic diagram of a cross-sectional design of a bending-resistant multimode optical fiber according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of a test cross-section of a bending-resistant multimode optical fiber provided by an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of the center delay difference of the fiber pulse provided by an embodiment of the present invention.
  • the present invention provides a bending resistant multimode optical fiber, which includes a core layer 1 and an inner cladding layer 2 with a graded refractive index, and a depressed layer 3 and an outer cladding layer 4 with a step refractive index in sequence from the center of the fiber.
  • the refractive index of the core layer 1 relative to the outer cladding layer presents an ⁇ -power exponential function distribution with the increase in radius
  • ⁇ is the refractive index profile distribution parameter of the core layer
  • the refractive index of the depressed layer 3 is the smallest.
  • the refractive index of the inner cladding layer relative to the outer cladding layer starts from the refractive index of the outer boundary of the core layer relative to the outer cladding layer, and increases with the radius It is gradually reduced to adjust the transmission rate and bandwidth of higher-order modes.
  • the present invention optimizes and regulates the interference of the core-cladding interface to the transmission rate of high-order modes by adding an inner cladding layer 2 with a continuously adjustable refractive index between the core layer 1 and the depressed layer 3, and improves the transmission bandwidth of the optical fiber.
  • the inner cladding layer is relatively
  • the refractive index of the outer cladding layer presents an oblique straight line section or a curved section with the increase of the radius. Please refer to FIG. 3 together.
  • the refractive index of the inner cladding layer relative to the outer cladding layer is an oblique straight line segment with an increase in radius (the oblique straight line segment shown in the solid line part of FIG.
  • ⁇ appears in the range of less than 45°.
  • the refractive index of the inner cladding layer relative to the outer cladding layer is curved as the radius increases (as shown by the dashed part in FIG. 3), and the end point of the curved line is relative to the starting point.
  • the included angle ⁇ is limited to less than 45°. This is because the inventors have found through a lot of experiments that the refractive index of the inner cladding of the fiber whose bandwidth and high-order mode transmission rate are optimized all appear in the above range, but not in the above range. For the above range, if the included angle ⁇ is greater than or equal to 45°, the width, starting point, and/or relative refractive index of the inner cladding are adjusted, and the bandwidth and high-order mode transmission rate of the fiber cannot achieve the equivalent technical effects of the present invention. The invention limits this range, thereby further reducing the difficulty of optimizing the design of optical fiber performance.
  • the refractive index distribution of the multimode optical fiber satisfies a first relational expression, and the first relational expression is:
  • n(r) is the refractive index at the radius r
  • ⁇ 0 is the relative refractive index difference between the center of the core layer and the inner boundary of the inner cladding layer.
  • R g is a layer of the core
  • n 1 is R g with respect to the outer cladding refractive index
  • n 2 is the R u with respect to the outer cladding refractive Rate
  • Ru is the outer diameter of the inner cladding and the inner diameter of the depressed layer
  • n 3 is a constant
  • n 3 is the refractive index of the depressed layer
  • n c is the refractive index of the outer cladding
  • R f is The outer diameter of the depressed layer and the inner diameter of the outer cladding layer
  • R max is the outer diameter of the outer cladding layer.
  • the optical fiber in the example where the refractive index of the inner cladding is linearly distributed, the optical fiber includes a core layer 1, an inner cladding layer 2, a depressed layer 3, and an outer cladding layer 4 from the inside to the outside.
  • each layer The radius refers to the distance from the outer boundary of the corresponding layer to the center of the core layer, for example, the inner cladding radius is the distance from the outer boundary of the inner cladding layer to the center of the core layer.
  • the center of the core layer is marked as the zero point, the radius is the horizontal axis, and the refractive index is the vertical axis.
  • the outer cladding layer is a pure silica layer, also called a silica layer.
  • refractive index n c is the refractive index of silica.
  • the relative refractive index of the other layers refers to the difference in refractive index with respect to silica.
  • the outer cladding layer For the silicon dioxide layer the relative refractive index of the other layers is the difference between the refractive index of each layer and the outer cladding layer.
  • the refractive index of the outer cladding layer in the present invention is the reference refractive index, that is, the refractive index of the outer cladding layer overlaps on the horizontal axis.
  • the outer cladding layer is a silicon dioxide layer
  • the refractive index is n c
  • the outer diameter of the outer cladding layer is 62.5 ⁇ 2.5 ⁇ m.
  • the refractive index of the depressed layer is n 3 , which is mainly a fluorine-doped layer.
  • the refractive index ⁇ 2 (ie n 3 -n c ) of the depressed layer relative to the outer cladding layer is -0.006 to -0.0025.
  • the width R f -R u is 2.5 to 5.5 ⁇ m.
  • the refractive index of the core layer relative to the outer cladding layer presents an ⁇ -power exponential function distribution as the radius increases.
  • ⁇ is the refractive index profile distribution parameter of the core layer, the refractive index at the center of the core layer is the largest, and the relative refractive index is ⁇ 1 (ie n 0 -n c ).
  • the interface between the core layer and the inner cladding layer is referred to as a R g, a refractive index of n-1; in particular, with respect to the center of the core layer to the outer cladding refractive index ⁇ 1 in the range of 0.013 to 0.016, the ⁇ is 1.90-2.10; R g of the The range is 22-32 ⁇ m; the refractive index at R g is n 1 , and the refractive index at R g is in the range of 0.0005 to 0.002 relative to the refractive index n 1 -n c of the outer cladding layer.
  • n 1 is the refractive index at the interface between the inner cladding and the core layer, which is also the refractive index at the outer interface of the core layer N 2 is the refractive index at the interface between the inner cladding layer and the depressed layer, and also the refractive index at the outer interface of the inner cladding layer.
  • N 2 is the refractive index at the interface between the inner cladding layer and the depressed layer, and also the refractive index at the outer interface of the inner cladding layer.
  • the R u with respect to the outer cladding refractive index of n 1 -n c ranges from 0.0005 -0.0005; width of said inner cladding R u -R g of 3 ⁇ 5.5 ⁇ m.
  • the difference from the above-mentioned example of oblique straight line section distribution is that the inner cladding is from R g to Ru , and the corresponding refractive index is curved from n 1
  • the gradient is n 2 , which approximates a parabolic distribution, where n 1 is the refractive index at the interface between the inner cladding and the core layer, which is also the refractive index at the outer interface of the core layer, and n 2 is the refractive index at the interface between the inner cladding and the sink layer, It is also the refractive index at the outer interface of the inner cladding, and the relationship between the refractive index of the inner cladding and the radius is as follows.
  • the R u with respect to the outer cladding refractive index of n 1 -n c ranges from 0.0005 -0.0005; width of said inner cladding R u -R g of 3 ⁇ 5.5 ⁇ m.
  • the core layer 1 may be doped with germanium dioxide and fluorine, or also include a small amount of phosphorus pentoxide, and the refractive index of the core layer can be controlled by the doping amount design of the above dopants.
  • germanium dioxide and phosphorous pentoxide are the upper dopants to help increase the refractive index
  • fluorine is the lower dopant, which can reduce the refractive index
  • the mixing of these dopants can achieve the optimization of the core layer profile distribution parameters and viscosity , Help to improve the viscosity matching of the core layer and inner cladding layer, and adjust the bandwidth of the optical fiber.
  • the intersection point (can be regarded as the inflection point) is g, where the radius is R g , the refractive index is n 1 , and the refractive index relative to the outer cladding layer is dn g ; the intersection point of the refractive index of the inner cladding layer and the depressed layer is u, where the radius is R u , the refractive index is n 2 , and the refractive index relative to the outer cladding is dn u .
  • the inner cladding layer 2 By increasing the inner cladding layer 2 with a graded refractive index, the continuous transition from the core layer 1 to the inner cladding layer 2 (inflection point g), and the refractive index difference (n 2 -n 3 ⁇ n 1 -n 3 ), which improves the refractive index mutation between the core layer and the inner cladding/sag layer, which causes the high-order mode at the boundary to show multiple pulses, resulting in the delay of the high-order mode, and avoids the phenomenon of delay in the core layer.
  • the use of multiple outer ring structures to transfer higher-order modes between the submerged layer and the lowered layer leads to an increase in the size of the optical fiber and limited applications.
  • the present invention adopts the graded index inner cladding to realize the compensation process of high-order mode as follows: as Ru and/or n 1 increase, the compensation for the transmission rate of the high-order mode will increase, the delay of the high-order mode will decrease, and the fiber bandwidth will increase; on the contrary, R When u and/or n 1 decrease, the compensation will decrease, the high-order mode delay will increase, and the fiber bandwidth will decrease. Therefore, theoretically adjusting the refractive index line segment distribution and parameters of the inner cladding combined with the fiber refractive index distribution relationship can continuously adjust the high-order mode transmission rate at R g , thereby effectively reducing or suppressing the cladding interface effect and increasing the bandwidth.
  • the refractive index profile can be achieved by MCVD or PCVD process.
  • the effective mode bandwidth (EMB) is calculated to be 2750MHZ/km, @850 full injection bandwidth 6740MHZ/km, @1300 full injection bandwidth 470MHZ/km, which is a Class B fiber; fiber bending loss R7.5-2 Circle@850 is 0.028dB, R15-2 circle@850 is 0.004dB, R7.5-2 circle@1300 is 0.079dB, R15-2 circle@1300 is 0.018dB; the delay difference at the boundary (core-cladding boundary) It is 0.0688ps/m, specifically as shown by curve 51 in FIG. 5, the multimode fiber in this example can be prepared by MCVD or PCVD process.
  • the calculated effective mode bandwidth (EMB) is 5215MHZ/km, @850 full injection bandwidth 1509MHZ/km, @1300 full injection bandwidth 739MHZ/km, which meets the OM3 bandwidth standard; fiber bending loss R7.5-2 circle @850 is 0.007dB, R15-2 circle@850 is 0.005dB, R7.5-2 circle@1300 is 0.04dB, R15
  • Example 1 Example 1 to Example 5 are shown in Table 1:
  • the present invention employs a linear or parabolic inner cladding cross-sectional design, no additional auxiliary layer structure, and may be the refractive index difference (n 1, n 2 and n c difference) and the adjusting point width (R u, R e ) Continuous adjustment to achieve effective compensation of the transmission rate of high-order modes at the core-clad interface, and improve fiber bandwidth performance and continuous controllability.
  • the continuously adjustable inner cladding profile design the problem of interfacial performance mismatch caused by the large difference in core-cladding viscosity in the previous platform layer design structure is alleviated.
  • the optical fiber designed by the present invention can continuously control design parameters for different application occasions, has strong designability, is adjustable and controllable, and reduces the difficulty of control design compared with the actual performance requirements of existing products.
  • the broadband designed by the present invention Bend-resistant multimode fiber will be widely used in short-distance and high-density fields such as local area networks, data centers, cloud computing, and computing centers in the future.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Optical Communication System (AREA)
  • Glass Compositions (AREA)

Abstract

一种抗弯多模光纤，从光纤中心向外依次包括具有渐变折射率的纤芯层（1）和内包层（2）及具有阶跃折射率的下陷层（3）和外包层（4），其中，纤芯层（1）相对外包层（4）的折射率随半径的增加呈α幂指数函数分布，α为纤芯层折射率剖面分布参数，纤芯层（1）中心的折射率最大，下陷层（3）的折射率最小，内包层（2）相对外包层（4）的折射率始于纤芯层（1）的外边界相对于外包层（4）的折射率，且随半径的增加呈逐渐减小来调控高阶模传输速率和带宽。多模光纤在纤芯层（1）与下陷层（3）之间设置了折射率渐变连续可调的内包层（2），使纤芯层（1）与下陷层（3）之间的折射率逐渐过渡，减少芯-包边界对高阶模传输速率的干扰，以提高光纤传输带宽。

Description

抗弯多模光纤 技术领域
本发明涉及光纤技术领域，特别是指一种抗弯多模光纤。
背景技术
多模光纤以其低廉的系统成本和较大的传输容量等优势，在中短距离网络系统，特别是数据中心中得到广泛应用。近年来，随着FTTX、物联网、云计算、云存储等新技术的迅速发展，网络数据通讯量呈指数级上升趋势，对多模光纤的传输性能要求不断提高。尤其在数据中心、超级计算中心这类大型局域网系统中，高速数据传输需要在有限空间内布放更多光纤链路，光纤经常会经受不同程度的弯曲，而多模光纤中传输的高阶模很容易在光纤弯曲时从包层中泄露出去，光纤衰减增加，从而可能会导致信号失真，增加了系统出现误码的可能，因此，为了满足未来400Gb/s，甚至是1Tb/s以太网数据传输，需要开发兼备高带宽和低弯曲损耗性能的多模光纤。
目前，常用的降低弯曲损耗的方法采用下陷层设计，通过增加深下陷层，在光纤发生宏弯时会有效将高阶模限制在下陷层，减少高阶模的泄露，从而降低光纤弯曲损耗。另外，为了获取较高的传输容量，多模光纤应该具有尽可能宽的带宽，对于给定的波长，光纤带宽可以用“满注入”(只适用于径向呈均匀发射的光源)和“有效模式”两种方式表征，其中，通过在径向不同位置连续注入至少24个给定波 长的相同光脉冲来获得色散模式延迟(DMD)数据，从这些测量中可以测定模式色散以及计算出有效模式带宽。模式延迟越大，相邻脉冲之间因展宽而重叠比例越高，降低了光纤的传输带宽。为了降低光纤模间色散，需要将多模光纤的纤芯层折射率剖面设计为具有幂指数分布的抛物线结构，从而通过调节纤芯层分布指数来优化带宽性能。然而，实际传输过程中有些高阶模不能完全限制在纤芯层内，会有部分在下陷层传输，由于芯-包(纤芯层和下陷层)边界处的折射率突变，高阶模式不能被适当补偿，往往在色散模式延迟(DMD)测量中会出现边界处高阶模显示出多脉冲，导致信号响应时间展宽，模式延迟增加，带宽性能降低。这种芯-包层界面效应对带宽影响，在弯曲不敏感多模光纤中尤其凸显，深下陷层与纤芯层边界折射率差较大，较高阶模比其它模式传播要么更快要么更慢，造成严重的脉冲畸变，影响带宽性能。另外，纤芯层与下陷层由于折射率差较大，光线组分差异较大，导致在芯棒制作和拉丝过程中，界面由于粘度差异大很容易产生汽包或者高应力等问题，影响产品性能。
现有技术中通常采用在纤芯层与下陷层增加平台层的方式来补偿芯-包界面效应对高阶模的影响，具体如图1所示，其中，平台层的折射率为定值，其值等于平台层和纤芯层交界面处的折射率。但是，由于平台层与下陷层之间的折射率差仍旧较大，折射率剖面的不连续性，仍会影响高阶模在界面处的传输速率，影响多模光纤的带宽性能。
鉴于此，如何提供一种具有高带宽的抗弯多模光纤成为本领域技术人员目前需要解决的问题。
发明内容
鉴于以上内容，有必要提供一种改进的抗弯多模光纤，在使用过程中能够减少芯-包边界对高阶模传输速率的干扰，提高光纤传输带宽，并且还能够减少粘度差对光纤性能的影响。
本发明提供的技术方案为：一种抗弯多模光纤，从光纤中心向外依次包括具有渐变折射率的纤芯层和内包层及具有阶跃折射率的下陷层和外包层，其中，所述纤芯层相对所述外包层的折射率随半径的增加呈α幂指数函数分布，α为所述纤芯层折射率剖面分布参数，所述纤芯层中心的折射率最大，所述下陷层的折射率最小，所述内包层相对所述外包层的折射率始于所述纤芯层的外边界相对于所述外包层的折射率，且随半径的增加呈逐渐减小来调控高阶模传输速率和带宽。
进一步的，所述内包层相对所述外包层的折射率随半径的增加呈斜直线段或曲线段。
进一步的，所述内包层相对所述外包层的折射率随半径的增加呈斜直线段，所述斜直线段相对于起点水平方向逆时针旋转的角度小于45°。
进一步的，所述内包层相对所述外包层的折射率随半径的增加呈曲线段，所述曲线段的端点连线相对于起点水平方向逆时针旋转的角度小于45°，所述曲线段和所述曲线段的端点连线的相对所述外包层的折射率之差随半径的增加由零逐渐增大，然后减小至零。
进一步的，所述多模光纤的折射率分布满足第一关系式，所述第一关系式为：
Figure PCTCN2020076435-appb-000001
其中，n(r)为半径为r处的折射率，n 0为所述纤芯层中心r＝0处的折射率，Δ 0为所述纤芯层中心和内包层内边界相对折射率差，R g为所述纤芯层的外径及所述内包层的内径，n 1为R g处相对于所述外包层的折射率，n 2为R u处相对于所述外包层的折射率；R u为所述内包层的外径和所述下陷层的内径，n 3为常数，n 3为所述下陷层的折射率，n c为所述外包层的折射率，R f为所述下陷层的外径及所述外包层的内径，R max为所述外包层的外径。
进一步的，所述纤芯层中心相对于所述外包层的折射率范围为0.013～0.016，所述α为1.90-2.10。
进一步的，所述R g的范围为22-32μm。
进一步的，所述R g处相对于所述外包层的折射率范围为0.0005～0.002；所述R u处相对于所述外包层的折射率范围为-0.0005～0.0005。
进一步的，所述内包层的宽度为3～5.5μm。
进一步的，所述下陷层相对于所述外包层的折射率为-0.006～-0.0025。
进一步的，所述下陷层的宽度为2.5～5.5μm。
进一步的，所述外包层为二氧化硅层。
进一步的，所述外包层的外径为62.5±2.5μm。
与现有技术相比，本发明提供的多模光纤在纤芯层与下陷层之间设置了折射率渐变连续可调的内包层，使纤芯层与下陷层之间的折射率逐渐过渡，避免纤芯层与下陷层之间的折射率发生突变，从而减少芯-包边界对高阶模传输速率的干扰，以提高光纤传输带宽，并且由于连续可调节内包层剖面设计，还减少了粘度差对光纤性能的影响。
附图说明
下面结合附图和具体实施方式对本发明作进一步详细的说明。
图1为现有技术中的一种纤芯层与下陷层的连接结构设计示意图。
图2为本发明实施例提供的一种抗弯多模光纤的切面结构示意图。
图3为本发明实施例提供的一种抗弯多模光纤剖面设计示意图。
图4为本发明实施例提供的一种抗弯多模光纤的测试剖面示意图。
图5为本发明实施例提供的光纤脉冲中心时延差示意图。
主要元件符号说明:
纤芯层   1
内包层   2
下陷层   3
外包层   4
如下具体实施方式将结合上述附图进一步说明本发明实施例。
具体实施方式
为了能够更清楚地理解本发明实施例的上述目的、特征和优点，下面结合附图和具体实施方式对本发明进行详细描述。需要说明的是，在不冲突的情况下，本申请的实施方式中的特征可以相互组合。
在下面的描述中阐述了很多具体细节以便于充分理解本发明实施例，所描述的实施方式仅是本发明一部分实施方式，而不是全部的实施方式。基于本发明中的实施方式，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施方式，都属于本发明实施例保护的范围。
除非另有定义，本文所使用的所有的技术和科学术语与属于本发明实施例的技术领域的技术人员通常理解的含义相同。本文中在本发明的说明书中所使用的术语只是为了描述具体的实施方式的目的，不是旨在于限制本发明实施例。
请参阅图2，本发明提供一种抗弯多模光纤，从光纤中心向外依次包括具有渐变折射率的纤芯层1和内包层2及具有阶跃折射率的下陷层3和外包层4，其中，所述纤芯层1相对所述外包层的折射率随半径的增加呈α幂指数函数分布，α为所述纤芯层折射率剖面分布参数，所述纤芯层1中心的折射率最大，所述下陷层3的折射率最小，所述内包层相对所述外包层的折射率始于所述纤芯层的外边界相对于所述外包层的折射率，且随半径的增加呈逐渐减小来调控高阶模传输速率和带宽。
本发明通过在纤芯层1和下陷层3之间增加折射率渐变连续可调的内包层2来优化调控芯-包界面对高阶模传输速率的干扰，并提高光纤传输带宽，所述内包层相对所述外包层的折射率随半径的增加呈斜直线段或曲线段。请一并参阅图3，在一具体实施方式中，所述内包层相对所述外包层的折射率随半径的增加呈斜直线段(如图3实线部分所示斜的直线段)，所述斜直线段相对于起点水平方向逆时针旋转的角度θ小于45°，如图3所示，斜直线段的起点为(R g，dn g＝n g-n c)，斜直线段的终点为(R u，dn u＝n u-n c)，起点水平方向相当于起点(R g，dn g)与(R u，dn g)之间的连线或射线或极轴，其中R u＞R g，θ即为斜直线段相对于起点水平方向逆时针旋转的角度，并且所述内包层相对所述外包层的折射率随半径的增加呈下降变化，本发明中光纤性能较优化时θ出现在小于45°的范围内。在另一具体实施方式中，所述内包层相对所述外包层的折射率随半径的增加呈曲线段(如图3虚线部分所示曲线段)，所述曲线段的端点连线相对于起点水平方向逆时针旋转的角度θ小于45°，如图3所示，曲线段的起点为(R g，dn g＝n g-n c)，曲线段的终点为(R u，dn u＝n u-n c)，所述曲线段的端点连线为起点(R g，dn g)与终点(R u，dn u)之间的线段，同上，起点水平方向相当于起点(R g，dn g)与(R u，dn g)之间的连线或射线或极轴，其中R u＞R g，θ即为所述曲线段的端点连线相对于起点水平方向逆时针旋转的角度，而且从图中还可以看出，所述曲线段和所述曲线段的端点连线的相对所述外包层的折射率之差随半径的增加由零逐渐增大，然后减小至零。具体的讲，在具体实施方式中限定夹角θ小于45°，这是因为发明人通过大量实验发现，带宽 及高阶模传输速率得以优化的光纤的内包层折射率均出现在上述范围内，而不在上述范围，如当该夹角θ大于或等于45°时，调整内包层的宽度、起始点和/或相对折射率，光纤的带宽和高阶模传输速率得不到本发明的等同技术效果，所以本发明限定该范围，进而进一步减小对光纤性能优化设计的难度。
在具体实施方式中，所述多模光纤的折射率分布满足第一关系式，所述第一关系式为：
Figure PCTCN2020076435-appb-000002
其中，n(r)为半径为r处的折射率，n 0为所述纤芯层中心r＝0处的折射率，△ 0为所述纤芯层中心和内包层内边界相对折射率差，R g为所述纤芯层的外径及所述内包层的内径，n 1为R g处相对于所述外包层的折射率，n 2为R u处相对于所述外包层的折射率；R u为所述内包层的外径和所述下陷层的内径，n 3为常数，n 3为所述下陷层的折射率，n c为所述外包层的折射率，R f为所述下陷层的外径及所述外包层的内径，R max为所述外包层的外径。
如图3示出的内包层折射率为线型分布的实例中，光纤从内至外依次包括纤芯层1、内包层2、下陷层3和外包层4，如图2所示，各层半径是指相应层外边界至纤芯层中心的距离，例如内包层半径即内包层外边界至纤芯层中心的距离。图3中以纤芯层中心记为零点，以半径为水平轴，折射率为垂直轴。其中外包层为纯石英层，也称二 氧化硅层，其折射率n c为二氧化硅的折射率，其他各层的相对折射率均指相对于二氧化硅的折射率差，这里外包层为二氧化硅层，其他各层的相对折射率也即是各层与外包层的折射率差，本发明以外包层折射率为基准折射率，即外包层折射率重合在水平轴上。在本实施例中，所述外包层为二氧化硅层，折射率为n c，所述外包层的外径为62.5±2.5μm。所述下陷层的折射率为n 3，主要为掺氟层，下陷层相对于所述外包层的折射率△ 2(即n 3-n c)为-0.006～-0.0025，所述下陷层的宽度R f-R u为2.5～5.5μm。纤芯层相对所述外包层的折射率随半径的增加呈α幂指数函数分布。
Figure PCTCN2020076435-appb-000003
其中，α为所述纤芯层折射率剖面分布参数，所述纤芯层中心的折射率最大，相对折射率为△ 1(即n 0-n c)，纤芯层与内包层的界面处记为R g，折射率为n 1；具体地，所述纤芯层中心相对于所述外包层的折射率△ 1范围为0.013～0.016，所述α为1.90-2.10；所述R g的范围为22-32μm；所述R g处折射率为n 1，R g处折射率相对于所述外包层的折射率n 1-n c范围为0.0005～0.002。从R g至R u为所述内包层，相应的折射率从n 1线性渐变为n 2，其中n 1为内包层与纤芯层的界面处折射率，也是纤芯层的外界面处折射率，n 2为内包层与下陷层的界面处折射率，也是内包层外界面处折射率，内包层折射率随半径的变化关系符合下式。
Figure PCTCN2020076435-appb-000004
具体的，所述R u处相对于所述外包层的折射率n 1-n c范围为-0.0005～0.0005；所述内包层的宽度R u-R g为3～5.5μm。
如图3示出的内包层折射率为曲线段的实例中，与上述斜直线段分布实例不同之处在于，从R g至R u为所述内包层，相应的折射率从n 1呈曲线渐变为n 2，近似抛物线分布，其中n 1为内包层与纤芯层的界面处折射率，也是纤芯层的外界面处折射率，n 2为内包层与下陷层的界面处折射率，也是内包层外界面处折射率，内包层折射率随半径的变化关系如下式。
Figure PCTCN2020076435-appb-000005
具体的，所述R u处相对于所述外包层的折射率n 1-n c范围为-0.0005～0.0005；所述内包层的宽度R u-R g为3～5.5μm。
以上具体实施方式中，纤芯层1可以掺杂有二氧化锗和氟，或还包括少量的五氧化二磷，通过以上掺杂剂的掺杂量设计可以实现纤芯层折射率的调控，如二氧化锗和五氧化二磷为上掺剂，有助折射率提高，氟为下掺剂，可以降低折射率，且这些掺杂剂的混合可以实现纤芯层剖面分布参数和粘度的优化，有助于提高纤芯层和内包层的粘度匹配，并调节光纤的带宽。以上实施方式，如图3所示，纤芯层折射率曲线到水平轴的延伸点为e，此处半径为R e，折射率为n e＝n c，纤芯层与内包层折射率的交点(可视为拐点)为g，此处半径为R g，折射率为n 1，相对外包层的折射率为dn g；内包层与下陷层折射率的交点为u，此处半径为R u，折射率为n 2，相对于外包层的折射率为dn u。通过增加折射率渐变的内包层2，从纤芯层1至内包层2连续过渡变化(拐点g)，且减小了纤芯层1直接变化至下陷层3的折射率差(n 2-n 3＜n 1-n 3)，改善了纤芯层与内包层/下陷层之间存在折射率突变而造成 边界处高阶模显示出多脉冲，产生高阶模的延迟的现象，同时避免了在纤芯层和下陷层之间采用多个外环结构来转移高阶模而导致光纤尺寸增大、应用受限的不足。本发明采用渐变折射率内包层实现高阶模的补偿过程如下：随着R u和/或n 1的增加，对高阶模传输速率的补偿会增大，高阶模延迟减小，光纤带宽增加；相反的，R u和/或n 1减小时，补偿会减小，高阶模延迟增大，光纤带宽减小。因而，理论上调节内包层的折射率线段分布和参数结合光纤折射率分布关系式可以连续调节R g处高阶模传输速率，从而有效减小或抑制包层界面效应，提高带宽。折射率剖面可以通过MCVD或PCVD工艺实现。
下面具体举例对本发明的抗弯曲多模光纤的性能进行检测和举例说明。
实施例1
R u-R g为3.4μm；拐点处半径R g为25.1μm，相对折射率n 1-n c＝1.35*10 -3；调节点u半径R u为27.0μm，相对折射率n 2-n c为-0.54*10 -3，与延伸点e距离R u-R e为0.2μm；下陷掺F层(也即下陷层)的相对折射率Δ 2＝n 3-n c为-5.1*10 -3；根据DMD测试结果计算有效模式带宽(EMB)为2750MHZ/km，@850满注入带宽6740MHZ/km，@1300满注入带宽470MHZ/km，为B级纤；光纤弯损R7.5-2圈@850为0.028dB，R15-2圈@850为0.004dB，R7.5-2圈@1300为0.079dB，R15-2圈@1300为0.018dB；边界(芯-包边界)处时延差为0.0688ps/m，具体如图5中的曲线51所示，该实例中的多模光纤可采用MCVD或PCVD工艺制备预制棒。
实施例2
R u-R g为5.2μm；拐点处半径R g为24.6μm，相对折射率n 1-n c＝1.1*10 -3；调节点u半径R u为25.9μm，相对折射率n 2-n c为0.35*10 -3，与延伸点e距离R u-R e为0.7μm；下陷掺F层的相对折射率Δ 2＝n 3-n c为-4.9*10 -3；根据DMD测试结果计算有效模式带宽(EMB)为5215MHZ/km，@850满注入带宽1509MHZ/km，@1300满注入带宽739MHZ/km，满足OM3带宽标准；光纤弯损R7.5-2圈@850为0.007dB，R15-2圈@850为0.005dB，R7.5-2圈@1300为0.04dB，R15-2圈@1300为0.011dB；芯-包边界处时延差为-0.2785ps/m，其中，与本实施例中的具体抗弯多模光纤对应的测试剖面示意图如图4所示，且脉冲中心时延差曲线具体如图5中的曲线52所示，该实例的多模光纤可采用MCVD或PCVD工艺制备预制棒。
实施例3
R u-R g为3.4μm；拐点处半径R g为25.3μm，相对折射率n 1-n c＝1.3*10 -3；调节点u半径R u为27.1μm，相对折射率n 2-n c为-0.3*10 -3，与延伸点e距离R u-R e为0.4μm；下陷掺F层的相对折射率Δ 2为-5.1*10 -3；根据DMD测试结果计算有效模式带宽(EMB)为1840MHZ/km，@850满注入带宽1633MHZ/km，@1300满注入带宽734MHZ/km，满足OM2+带宽标准；光纤弯损R7.5-2圈@850为0.04dB，R15-2圈@850为0.032dB，R7.5-2圈@1300为0.094dB，R15-2圈@1300为0.029dB；芯-包边界处时延差为-0.301ps/m，具体如图5中的曲线53所示，该实例的多模光纤可采用MCVD或PCVD工艺制备预制棒。
实施例4
R u-R g为5.1μm；拐点处半径R g为24.5μm，相对折射率n 1-n c＝1.1*10 -3；调节点u半径R u为26μm，相对折射率n 2-n c为-0.1*10 -3，与延伸点e距离R u-R e为0.3μm；下陷掺F层的相对折射率Δ 2为-4.9*10 -3；根据DMD测试结果计算有效模式带宽(EMB)为4540MHZ/km，@850满注入带宽3750MHZ/km，@1300满注入带宽653MHZ/km，满足OM3带宽标准；光纤弯损R7.5-2圈@850为0.043dB，R15-2圈@850为0.009dB，R7.5-2圈@1300为0.129dB，R15-2圈@1300为0.026dB；芯-包边界处时延差为-0.1613ps/m，具体如图5中的曲线54所示，该实例的多模光纤可采用MCVD或PCVD工艺制备预制棒。
实施例5
R u-R g为5.1μm；拐点处半径R g为24.3μm，相对折射率n 1-n c＝1.2*10 -3；调节点u半径R u为25.7μm，相对折射率n 2-n c为0.4*10 -3，与延伸点e距离R u-R e为0.5μm；下陷掺F层的相对折射率Δ 2为-3.4*10 -3；根据DMD测试结果计算有效模式带宽(EMB)为8026MHZ/km，@850满注入带宽5090MHZ/km，@1300满注入带宽555MHZ/km，满足OM4带宽标准；光纤弯损R7.5-2圈@850为0.137dB，R15-2圈@850为0.028dB，R7.5-2圈@1300为0.255dB，R15-2圈@1300为0.048dB；芯-包边界处时延差为-0.0971ps/m，具体如图5中的曲线55所示，该实例的多模光纤可采用MCVD或PCVD工艺制备预制棒。
需要说明的是，DMD的具体测试方法为现有技术，本实施例在 此不再详述。其中，例1至例5中的各个参数如表1所示：
表1
Figure PCTCN2020076435-appb-000006
综上，本发明采用内包层抛物线或线性剖面设计，不需要增加辅助层结构，且可以通过折射率差(n 1，n 2与n c的差值)和调节点宽度(R u，R e)连续调节，实现高阶模在芯-包界面处传输速率得到有效补偿，提高光纤带宽性能和连续可控性。而且，通过连续可调节内包 层剖面设计，缓解了以往平台层设计结构由于芯-包层粘度差异大而引起的界面性能失配问题。另外，本发明设计的光纤可针对不同应用场合进行设计参数连续调控，可设计性强，可调可控，较现有产品实际性能的需要，降低了调控设计的难度，本发明所设计的宽带抗弯多模光纤在未来在局域网、数据中心、云计算、计算中心等短距离、高密度领域有着广泛的应用。
以上实施方式仅用以说明本发明实施例的技术方案而非限制，尽管参照以上较佳实施方式对本发明实施例进行了详细说明，本领域的普通技术人员应当理解，可以对本发明实施例的技术方案进行修改或等同替换都不应脱离本发明实施例的技术方案的精神和范围。

Claims (13)

  1. 一种抗弯多模光纤，其特征在于：从光纤中心向外依次包括具有渐变折射率的纤芯层和内包层及具有阶跃折射率的下陷层和外包层，其中，所述纤芯层相对所述外包层的折射率随半径的增加呈α幂指数函数分布，α为所述纤芯层折射率剖面分布参数，所述纤芯层中心的折射率最大，所述下陷层的折射率最小，所述内包层相对所述外包层的折射率始于所述纤芯层的外边界相对于所述外包层的折射率，且随半径的增加呈逐渐减小来调控高阶模传输速率和带宽。
  2. 根据权利要求1所述的抗弯多模光纤，其特征在于：所述内包层相对所述外包层的折射率随半径的增加呈斜直线段或曲线段。
  3. 根据权利要求2所述的抗弯多模光纤，其特征在于：所述内包层相对所述外包层的折射率随半径的增加呈斜直线段，所述斜直线段相对于起点水平方向逆时针旋转的角度小于45°。
  4. 根据权利要求2所述的抗弯多模光纤，其特征在于：所述内包层相对所述外包层的折射率随半径的增加呈曲线段，所述曲线段的端点连线相对于起点水平方向逆时针旋转的角度小于45°，所述曲线段和所述曲线段的端点连线的相对所述外包层的折射率之差随半径的增加由零逐渐增大，然后减小至零。
  5. 根据权利要求2所述的抗弯多模光纤，其特征在于：所述多模光纤的折射率分布满足第一关系式，所述第一关系式为：
    Figure PCTCN2020076435-appb-100001
    其中，n(r)为半径为r处的折射率，n 0为所述纤芯层中心r＝0处的折射率，Δ 0为所述纤芯层中心和内包层内边界相对折射率差，R g为所述纤芯层的外径及所述内包层的内径，n 1为R g处相对于所述外包层的折射率，n 2为R u处相对于所述外包层的折射率；R u为所述内包层的外径和所述下陷层的内径，n 3为常数，n 3为所述下陷层的折射率，n c为所述外包层的折射率，R f为所述下陷层的外径及所述外包层的内径，R max为所述外包层的外径。
  6. 根据权利要求2所述的抗弯多模光纤，其特征在于，所述纤芯层中心相对于所述外包层的折射率范围为0.013～0.016，所述α为1.90-2.10。
  7. 根据权利要求2所述的抗弯多模光纤，其特征在于，所述R g的范围为22-32μm。
  8. 根据权利要求2所述的抗弯多模光纤，其特征在于，所述R g处相对于所述外包层的折射率范围为0.0005～0.002；所述R u处相对于所述外包层的折射率范围为-0.0005～0.0005。
  9. 根据权利要求2所述的抗弯多模光纤，其特征在于，所述内包层的宽度为3～5.5μm。
  10. 根据权利要求2所述的抗弯多模光纤，其特征在于：所述下陷层相对于所述外包层的折射率为-0.006～-0.0025。
  11. 根据权利要求2所述的抗弯多模光纤，其特征在于：所述下 陷层的宽度为2.5～5.5μm。
  12. 根据权利要求2所述的抗弯多模光纤，其特征在于：所述外包层为二氧化硅层。
  13. 根据权利要求2所述的抗弯多模光纤，其特征在于，所述外包层的外径为62.5±2.5μm。
PCT/CN2020/076435 2019-12-24 2020-02-24 抗弯多模光纤 WO2021128563A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201911347783.X 2019-12-24
CN201911347783.XA CN111221073B (zh) 2019-12-24 2019-12-24 一种抗弯多模光纤

Publications (1)

Publication Number Publication Date
WO2021128563A1 true WO2021128563A1 (zh) 2021-07-01

Family

ID=70830853

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/076435 WO2021128563A1 (zh) 2019-12-24 2020-02-24 抗弯多模光纤

Country Status (2)

Country Link
CN (1) CN111221073B (zh)
WO (1) WO2021128563A1 (zh)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113608298B (zh) * 2021-10-11 2021-12-31 长飞光纤光缆股份有限公司 一种大模场直径弯曲不敏感单模光纤
CN115826130A (zh) * 2022-12-09 2023-03-21 江苏亨通光纤科技有限公司 一种弯曲不敏感高带宽多模光纤
CN116009141B (zh) * 2023-02-10 2024-01-12 烽火通信科技股份有限公司 一种dmd优化渐变多模光纤
CN116589174B (zh) * 2023-05-09 2024-06-28 中天科技光纤有限公司 石英预制件、光纤及光纤制备方法
CN116626805B (zh) * 2023-07-24 2023-10-13 中天科技光纤有限公司 超低损耗光纤及其制备方法
CN117348148B (zh) * 2023-12-05 2024-03-22 中天科技精密材料有限公司 高带宽多模光纤

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030156321A1 (en) * 2001-12-21 2003-08-21 Kent Leonard R. Large effective area erbium doped fiber optical amplifier
CN1721895A (zh) * 2004-06-23 2006-01-18 古河电子北美公司 具有减小接头损耗的光纤及其制作方法
CN101770051A (zh) * 2008-12-19 2010-07-07 三星光通信株式会社 低弯曲损耗光纤
CN107960119A (zh) * 2015-06-23 2018-04-24 康宁股份有限公司 用于多模和单模传输的光纤
CN209514123U (zh) * 2018-11-30 2019-10-18 中天科技精密材料有限公司 宽带抗弯多模光纤
CN110456446A (zh) * 2019-08-19 2019-11-15 长飞光纤光缆股份有限公司 一种单模光纤

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4127868C2 (de) * 1991-08-22 1994-11-10 Rheydt Kabelwerk Ag Einmoden-Faser mit rampenförmigem Brechzahl-Profil
US8385702B2 (en) * 2009-05-28 2013-02-26 Corning Incorporated Bend resistant multimode optical fiber
US8666214B2 (en) * 2011-11-30 2014-03-04 Corning Incorporated Low bend loss optical fiber
US9110220B2 (en) * 2013-07-16 2015-08-18 Corning Incorporated High bandwidth MMF and method of making

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030156321A1 (en) * 2001-12-21 2003-08-21 Kent Leonard R. Large effective area erbium doped fiber optical amplifier
CN1721895A (zh) * 2004-06-23 2006-01-18 古河电子北美公司 具有减小接头损耗的光纤及其制作方法
CN101770051A (zh) * 2008-12-19 2010-07-07 三星光通信株式会社 低弯曲损耗光纤
CN107960119A (zh) * 2015-06-23 2018-04-24 康宁股份有限公司 用于多模和单模传输的光纤
CN209514123U (zh) * 2018-11-30 2019-10-18 中天科技精密材料有限公司 宽带抗弯多模光纤
CN110456446A (zh) * 2019-08-19 2019-11-15 长飞光纤光缆股份有限公司 一种单模光纤

Also Published As

Publication number Publication date
CN111221073B (zh) 2022-07-22
CN111221073A (zh) 2020-06-02

Similar Documents

Publication Publication Date Title
WO2021128563A1 (zh) 抗弯多模光纤
EP2299303B1 (en) Multimode optical fibre with reduced bending losses
EP2333594B1 (en) High bandwidth multimode optical fiber
JP5685028B2 (ja) 改善した曲げ損失を有するマルチモード光ファイバ
KR101731715B1 (ko) 휨 저항성 멀티모드 광섬유
CN109188603B (zh) 小芯径渐变折射率光纤
WO2017020456A1 (zh) 一种超低衰耗弯曲不敏感单模光纤
WO2017101568A1 (zh) 一种高带宽抗弯多模光纤
EP2203767A1 (en) Multlmode fiber
CN109298482B (zh) 一种低衰减和低弯曲损耗的大有效面积单模光纤
WO2020162209A1 (ja) 光ファイバおよび光ファイバの製造方法
WO2019201147A1 (zh) 一种高带宽弯曲不敏感多模光纤
WO2021218094A1 (zh) 光纤
CN107102400B (zh) 一种高带宽弯曲不敏感多模光纤
WO2016173253A1 (zh) 一种超低衰耗弯曲不敏感单模光纤
TW201348767A (zh) 漸變折射率抗彎曲多模光纖
WO2020119439A1 (zh) 一种低损耗大有效面积单模光纤及其制备方法
CN113608298B (zh) 一种大模场直径弯曲不敏感单模光纤
CN114325928B (zh) 一种低损耗抗弯曲单模光纤
CN107193080B (zh) 高带宽弯曲不敏感多模光纤
CN110297288B (zh) 一种低衰减阶跃型轨道角动量光纤
WO2023240881A1 (zh) 一种陆地用g.654.e光纤及其制作工艺
US20200400879A1 (en) Optical fiber
CN108594361B (zh) 一种高带宽多模光纤
WO2020108141A1 (zh) 宽带抗弯多模光纤

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20905271

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20905271

Country of ref document: EP

Kind code of ref document: A1