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Modeling of Few-Mode Multi-Core Optical Fiber Channel Based on Non-Uniform Mode Field Distribution
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作者 Hang Zhou Bo Liu +6 位作者 Fu Wang Dandan Song Li Li Xiangjun Xin Qinghua Tian Qi Zhang Feng Tian 《China Communications》 SCIE CSCD 2016年第8期184-191,共8页
In this paper, the influencing factors that affect few-mode and multi core optical fiber channel are analyzed in a comprehensive way. The theoretical modeling and computer simulation of the information channel are car... In this paper, the influencing factors that affect few-mode and multi core optical fiber channel are analyzed in a comprehensive way. The theoretical modeling and computer simulation of the information channel are carried out and then the modeling scheme of few-mode multicore optical fiber channel based on non-uniform mode field distribution is put forward. The proposed modeling scheme can not only exponentially increases the system capacity through fewmode multi-core optical fiber channel, but has better transmission performance compared to the channel of the same type to the uniform channel revealing from the simulation results. 展开更多
关键词 few-mode multi-core optical fiber channel non-uniform channel channel modeling
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Wavelength switchable mode-locked fiber laser with a few-mode fiber filter
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作者 白少康 向昱锦 张祖兴 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期311-315,共5页
We have proposed and constructed a few-mode fiber(FMF)-based comb filter realized by dislocation splicing a fewmode long-period fiber grating(FM-LPFG) with a single-mode fiber(SMF). From an all-fiber laser with a FMF-... We have proposed and constructed a few-mode fiber(FMF)-based comb filter realized by dislocation splicing a fewmode long-period fiber grating(FM-LPFG) with a single-mode fiber(SMF). From an all-fiber laser with a FMF-based comb filter, the generation of switchable single-, dual-, triple-, and quadruple-wavelength continuous light has been achieved.Moreover, wavelength switchable mode-locked pulses have been obtained with the increased pump power. In the experiment, the output wavelength of the mode-locked fiber laser was changed from 1567.72 nm to 1571.04 nm, while the signal-to-noise(SNR) ratio was maintained above 61 d B. The switchable multiwavelength continuous wave(CW) and mode-locked all-fiber lasers have potentially important applications for fiber sensing, wavelength-division multiplexing(WDM) and signal processing. 展开更多
关键词 few-mode fiber mode-locked pulses few-mode long-period fiber comb filter
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Machine Learning-based Inverse Model for Few-Mode Fiber Designs
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作者 Bhagyalaxmi Behera Gyana Ranjan Patra +1 位作者 Shailendra Kumar Varshney Mihir Narayan Mohanty 《Computer Systems Science & Engineering》 SCIE EI 2023年第4期311-328,共18页
The medium for next-generation communication is considered as fiber for fast,secure communication and switching capability.Mode division and space division multiplexing provide an excellent switching capability with h... The medium for next-generation communication is considered as fiber for fast,secure communication and switching capability.Mode division and space division multiplexing provide an excellent switching capability with high data transmission rate.In this work,the authors have approached an inverse modeling technique using regression-based machine learning to design a weakly coupled few-mode fiber for facilitating mode division multiplexing.The technique is adapted to predict the accurate profile parameters for the proposed few-mode fiber to obtain the maximum number of modes.It is for a three-ring-core few-mode fiber for guiding five,ten,fifteen,and twenty modes.Three types of regression models namely ordinary least-square linear multi-output regression,k-nearest neighbors of multi-output regression,and ID3 algorithm-based decision trees for multi-output regression are used for predicting the multiple profile parameters.It is observed that the ID3-based decision tree for multioutput regression is the robust,highly-accurate machine learning model for fast modeling of FMFs.The proposed fiber claims to be an efficient candidate for the next-generation 5G and 6G backhaul networks using mode division multiplexing. 展开更多
关键词 few-mode fibers inverse modeling machine learning regression ring-core
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Theoretical Analysis on Inter-Core Crosstalk Suppression Model for Multi-Core Fiber
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作者 Jiajing Tu Xueqin Xie Keping Long 《China Communications》 SCIE CSCD 2016年第8期192-197,共6页
Decreasing mode coupling coefficient(κ) is an effective approach to suppress the inter-core crosstalk. Therefore, we deploy a low index rod and rectangle trench in the middle of two neighboring cores to reduce κ so ... Decreasing mode coupling coefficient(κ) is an effective approach to suppress the inter-core crosstalk. Therefore, we deploy a low index rod and rectangle trench in the middle of two neighboring cores to reduce κ so that the overlap of electric field distribution can be suppressed. We also propose approximate analytical solution(AAS) for κ of two crosstalk suppression models, which are two cores with one low index rod deployed in the middle and two cores with one low index rectangle trench deployed in the middle. We then do some modification for the results obtained by AAS and the modified results are proved to agree well with that obtained by finite element method(FEM). Therefore, we can use the modified AAS to get inter-core crosstalk for abovementioned two models quickly. 展开更多
关键词 multi-core fiber CROSSTALK mode coupling coefficient
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Fast mode decomposition for few-mode fiber based on lightweight neural network
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作者 赵佳佳 陈国辉 +3 位作者 毕轩 蔡汪洋 岳磊 唐明 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第2期88-95,共8页
In this paper,we present a fast mode decomposition method for few-mode fibers,utilizing a lightweight neural network called MobileNetV3-Light.This method can quickly and accurately predict the amplitude and phase info... In this paper,we present a fast mode decomposition method for few-mode fibers,utilizing a lightweight neural network called MobileNetV3-Light.This method can quickly and accurately predict the amplitude and phase information of different modes,enabling us to fully characterize the optical field without the need for expensive experimental equipment.We train the MobileNetV3-Light using simulated near-field optical field maps,and evaluate its performance using both simulated and reconstructed near-field optical field maps.To validate the effectiveness of this method,we conduct mode decomposition experiments on a few-mode fiber supporting six linear polarization(LP)modes(LP01,LP11e,LP11o,LP21e,LP21o,LP02).The results demonstrate a remarkable average correlation of 0.9995 between our simulated and reconstructed near-field lightfield maps.And the mode decomposition speed is about 6 ms per frame,indicating its powerful real-time processing capability.In addition,the proposed network model is compact,with a size of only 6.5 MB,making it well suited for deployment on portable mobile devices. 展开更多
关键词 deep learning lightweight neural network few-mode fiber mode decomposition
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多波长与横模可切换掺镱光纤激光器的研究
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作者 彭剑傲 陈伟 +4 位作者 侯超奇 刘丹丹 庞拂飞 黄素娟 王廷云 《光子学报》 EI CAS CSCD 北大核心 2024年第8期140-147,共8页
设计并制备了一种具有环形掺镱纤芯的光纤波导结构,并提出了一种基于该环芯掺镱光纤和少模光纤布拉格光栅的多波长与横模可切换光纤激光器。在这种光纤激光器中,只需简单调整腔内的偏振控制器,就可以实现单波长和双波长的激光稳定振荡... 设计并制备了一种具有环形掺镱纤芯的光纤波导结构,并提出了一种基于该环芯掺镱光纤和少模光纤布拉格光栅的多波长与横模可切换光纤激光器。在这种光纤激光器中,只需简单调整腔内的偏振控制器,就可以实现单波长和双波长的激光稳定振荡。当激光器在单波长下工作时,可以切换两种横模输出,包括LP01模和LP11模,两种模式都获得了小于0.08 nm的3 dB窄线宽和大于45 dB的高边模抑制比,中心波长和光强的波动分别为±0.01 nm和±1 dB。试验表明:该环芯掺镱光纤有助于LP11模获得的增益高于LP01模,LP01模式激光的斜率效率为34.34%,而LP11模式激光的斜率效率高达49.09%。该光纤激光器可以在模分复用系统和激光加工等领域发挥重要的作用。 展开更多
关键词 光纤激光器 多波长 横模可切换 环芯掺镱光纤 少模光纤光栅
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基于弱耦合多芯少模光纤光斑分析的扰动传感研究
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作者 袁晖 刘艳 +1 位作者 李广德 庞乐之 《半导体光电》 CAS 北大核心 2024年第4期523-529,共7页
提出了一种基于耦合多芯少模光纤(FM-MCF)光斑检测的光纤扰动传感器结构,并进行了实验验证。该传感器采用“单模光纤-多模光纤(MMF)-多芯少模光纤”的级联光纤结构,单模激光经过MMF进行光场发散后,FM-MCF中的7个芯子都能被照亮,因此在FM... 提出了一种基于耦合多芯少模光纤(FM-MCF)光斑检测的光纤扰动传感器结构,并进行了实验验证。该传感器采用“单模光纤-多模光纤(MMF)-多芯少模光纤”的级联光纤结构,单模激光经过MMF进行光场发散后,FM-MCF中的7个芯子都能被照亮,因此在FM-MCF的末端可以用相机接收到具有7个子光斑的光斑图像。实验中在FM-MCF不同位置处施加扰动并同时采集光斑,之后基于神经网络对变化的光斑图样进行处理以实现扰动位置分类。基于FM-MCF芯内强耦合、芯间弱耦合的特性,利用该光纤结构以3 cm的空间分辨率实现了对15个扰动位置的99.46%的高精度分类,远高于仅采用MMF通过光斑检测进行扰动定位的结果。也测试了FM-MCF传感器同时检测扰动位置和强度的能力,识别分类准确率均接近100%。实验结果表明,所提出的传感器具有成本低、结构简单、易于解调和高精度的优点。 展开更多
关键词 光纤光斑 多芯少模光纤 扰动传感 卷积神经网络
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Speckle backpropagation for compensation of nonlinear effects in few-mode optical fibers 被引量:1
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作者 Pavel S.Anisimov Evgeny D.Tsyplakov +1 位作者 Viacheslav V.Zemlyakov 高杰星 《Chinese Optics Letters》 SCIE EI CAS CSCD 2023年第3期24-28,共5页
We propose an alternative approach to compensation of intermodal interactions in few-mode optical fibers by means of digital backpropagation.Instead of solving the inverse generalized multimode nonlinear Schr?dinger e... We propose an alternative approach to compensation of intermodal interactions in few-mode optical fibers by means of digital backpropagation.Instead of solving the inverse generalized multimode nonlinear Schr?dinger equation,we accomplish backpropagation of the multimode signals with help of their near-field intensity distributions captured by a camera.We demonstrate that this task can successfully be handled by a deep neural network and provide a proof of concept by training an autoencoder for backpropagation of six linearly polarized[LP]modes of a step-index fiber. 展开更多
关键词 optical fibers multimode fibers few-mode fibers digital signal processing space division multiplexing mode division multiplexing mode decomposition
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Contactless vital signs monitoring based on few‐mode and multi‐core fibers 被引量:2
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作者 Fengze Tan Weimin Lyu +2 位作者 Shuyang Chen Zhengyong Liu Changyuan Yu 《Opto-Electronic Advances》 2020年第5期19-30,共12页
Few-mode and multi-core fibers are proposed and demonstrated for contactless vital signs monitoring in this paper.In-line optical fiber interferometers using few-mode and multi-core fibers are designed and offset spli... Few-mode and multi-core fibers are proposed and demonstrated for contactless vital signs monitoring in this paper.In-line optical fiber interferometers using few-mode and multi-core fibers are designed and offset splicing is utilized for mode excitation.Extinction ratio and insertion loss are analyzed experimentally under different offset distances.The fabricated in-line interferometers are packaged under the mattress to realize contactless vital signs signals collection.By using filtering techniques,both respiration and heartbeat signals can be recovered successfully,and respiration as well as heartbeat ratio are obtained.Mode excitation and interference are theoretically analyzed in few-mode fiber while curvature sensing experiments using multi-core fiber interferometer are performed to verify its excellent performance on vital signs monitoring.The successful demonstration on contactless vital signs monitoring makes few-mode and multi-core fibers promising candidates for healthcare applications. 展开更多
关键词 few-mode fiber multi-core fiber in-line interferometer vital signs monitoring
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Numerical analysis of photonic crystal fiber with chalcogenide core tellurite cladding composite microstructure 被引量:1
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作者 刘硕 李曙光 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第7期218-222,共5页
Kinds of photonic crystal fibers with chalcogenide core tellurite cladding composite microstructure are proposed. The multi-core photonic crystal fiber can reach the higher nonlinearity coefficient and the larger effe... Kinds of photonic crystal fibers with chalcogenide core tellurite cladding composite microstructure are proposed. The multi-core photonic crystal fiber can reach the higher nonlinearity coefficient and the larger effective mode area. The small single-core photonic crystal fiber has a very high nonlinearity coefficient. At the wavelength λ=0.8μm, the nonlinearity coefficient can reach 31.37053 W-1·m-1, at the wavelength λ=1.55μm, the nonlinearity coefficient is 11.19686W-1·m-1. 展开更多
关键词 multi-core photonic crystal fiber effective mode area nonlinearity coefficient dispersion
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Realization of a broadband terahertz wavelength-selective coupling based on five-core fibers
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作者 李绪友 于莹莹 +1 位作者 孙波 何昆鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第8期636-641,共6页
We propose a novel kind of wavelength-selective coupling for the terahertz range based on solid five-core fiber (FCF). The performances of coupling, propagation characteristics, and confinement loss properties are n... We propose a novel kind of wavelength-selective coupling for the terahertz range based on solid five-core fiber (FCF). The performances of coupling, propagation characteristics, and confinement loss properties are numerically investigated by using a full vector beam propagation method (BPM). Simulation results show that it is possible to realize a broad- band wavelength-selective coupling. The coupling length can reach 1.913 cm, and the confinement loss is better than 1.965 ×10^-4 cm^-1. Furthermore, a parameter, the power difference, is defined, and it numerically demonstrates the working performance of the wavelength-selective coupler; that is, when the power difference is better than - 15 dB, the frequency located in the range of 0.76 THz-100 THz is separated relatively well from the frequency of 0.3 THz. Finally, the effect of the structural parameter on the working performance of the coupler is also investigated. We show that the performance optimization is possible by appropriately tuning the core diameter, and the tunabilities of frequency and bandwidth are possible by appropriately tuning the pitch. The wavelength-selective coupler is of potential application for optical fiber sensing and communication in terahertz wavelength division multiplexer fields. 展开更多
关键词 TERAHERTZ terahertz waveguides COUPLING multi-core fiber
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Polarization Characteristics of the Deformed Low-Mode Fiber Waveguides with Polarization Conservation
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作者 Uygun V. Valiev Alexandr A. Simonov +1 位作者 Dejun Fu Davron R. Dzhuraev 《Journal of Electromagnetic Analysis and Applications》 2011年第4期128-132,共5页
In this work the results of polarization researches of low-optical fiber waveguides with conservation of polarization are presented. Obtained results quite convincingly testify regarding a high sensitivity low-mode re... In this work the results of polarization researches of low-optical fiber waveguides with conservation of polarization are presented. Obtained results quite convincingly testify regarding a high sensitivity low-mode regime of work of an optical fiber to anisotropic external influences, in comparison with one-mode regime of work of the same fibre. This result, can represent a big practical value at the realization of high-sensitivity fiber-optical devices of different physical values. 展开更多
关键词 Birefringent OPTICAL fiber SINGLE-MODE or few-mode OPTICAL fibers fiber-Optical Sensor POLARIZATION OPTICAL Modulator Circularly Polarized Light Photoelastic Effect Anisotropic Deformations
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弱耦合多芯少模光纤的声波导布里渊散射特性
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作者 张泽霖 周慧 +6 位作者 秦钰 许维维 蒋新力 曹珊珊 谢书鸿 沈一春 肖力敏 《光通信研究》 2023年第2期23-28,39,共7页
光纤中的声波导布里渊散射(GAWBS)可在较低光功率水平激发,该散射噪声对大容量空分复用光纤通信、数字相干传输及光量子传输影响较大。针对空分复用光纤通信系统,文章对自制弱耦合7芯4模光纤的GAWBS特性进行了理论和实验研究。结果表明... 光纤中的声波导布里渊散射(GAWBS)可在较低光功率水平激发,该散射噪声对大容量空分复用光纤通信、数字相干传输及光量子传输影响较大。针对空分复用光纤通信系统,文章对自制弱耦合7芯4模光纤的GAWBS特性进行了理论和实验研究。结果表明,由于不同纤芯与光纤中心的距离差异,弱耦合7芯4模光纤中不同纤芯具有明显的GAWBS分布差异。未来需要在不同的纤芯中采取不同的GAWBS噪声补偿方法以实现高信噪比和低误码率的空分复用传输。 展开更多
关键词 空分复用 多芯光纤 少模光纤 声波导布里渊散射 声光相互作用
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4.096 Tbit/s multidimensional multiplexing signals transmission over 1000 km few mode fiber 被引量:1
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作者 张宇 王晨 +8 位作者 王凯辉 丁俊杰 朱博文 沈磊 张磊 王瑞春 闫长鹍 刘博 余建军 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第1期8-13,共6页
We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division mul... We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication. 展开更多
关键词 optical fiber communication mode division multiplexing few-mode fiber multiple-input-multiple-output high-capacity transmission long-distance transmission
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Efficient silicon integrated four-mode edge coupler for few-mode fiber coupling 被引量:3
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作者 Junbo Zhu Haiyang Huang +3 位作者 Yingxuan Zhao Yang Li Zhen Sheng Fuwan Gan 《Chinese Optics Letters》 SCIE EI CAS CSCD 2022年第1期54-59,共6页
Here,we designed a broadband,low loss,compact,and fabrication-tolerant silicon-based four-mode edge coupler,composed of a 1×3 adiabatic mode-evolution counter-taper splitter and a triple-tip inverse taper.Based o... Here,we designed a broadband,low loss,compact,and fabrication-tolerant silicon-based four-mode edge coupler,composed of a 1×3 adiabatic mode-evolution counter-taper splitter and a triple-tip inverse taper.Based on mode conversion and power splitting,the proposed structure can simultaneously realize efficient mode coupling from TE_(0),TM_(0),TE_(1),and TM_(1) modes of multimode silicon waveguides to linearly polarized(LP),LP^(01,x),LP_(01,y),LP_(11a,x),and LP_(11a,y),modes in the few-mode fiber.To the best of our knowledge,we proposed the first scheme of four LP modes coupling,which is fully compatible with standard fabrication process.The 3D finite-difference time-domain simulation results show that the on-chip conversion losses of the four modes remain lower than 0.62 dB over the 200 nm wavelength range,and total coupling losses are 4.1 dB,5.1 dB,2.1 dB,and 2.9 dB for TE_(0)-to-LP_(01,x),TM_(0)-to-LP_(01,y),TE_(1)-to-LP_(11a,x),and TM_(1)-to-LP_(11a,y),respectively.Good fabrication tolerance and relaxed critical dimensions make the four-mode edge coupler compatible with standard fabrication process of commercial silicon photonic foundries. 展开更多
关键词 multimode coupling CMOS compatibility silicon waveguide few-mode fiber
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Fiber laser twist sensor with hybrid few-mode tilted Bragg grating and few-mode long period grating 被引量:2
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作者 YANG Kang LIU Yan-ge +4 位作者 WANG Zhi LI Guo-yu HAN Ya ZHANG Hong-wei MAO Bai-wei 《Optoelectronics Letters》 EI 2019年第3期161-164,共4页
A twist sensor with hybrid few-mode tilted fiber Bragg grating(FM-TFBG) and few-mode long period grating(FM-LPG) in fiber laser cavity is demonstrated. The FM-LPG is utilized to excite LP11 core mode. The FM-TFBG is u... A twist sensor with hybrid few-mode tilted fiber Bragg grating(FM-TFBG) and few-mode long period grating(FM-LPG) in fiber laser cavity is demonstrated. The FM-LPG is utilized to excite LP11 core mode. The FM-TFBG is used for sensing. The transverse modes at 1 553.9 nm and 1 550.5 nm are LP01 and LP21 core modes, respectively, which are coupled from forward-propagating LP11 core mode. These two excitation wavelengths have opposite variation tendencies, which participate in sensing. The twist sensitivity of 0.16 dB/° from-40° to 40° is achieved. The proposed sensor has potentially used for structure monitoring in many areas. 展开更多
关键词 LPG fiber laser TWIST SENSOR with hybrid few-mode tilted Bragg GRATING and few-mode long period GRATING
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Applications of weakly-coupled few-mode fibers[Invited] 被引量:2
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作者 Huiyuan Liu He Wen Guifang Li 《Chinese Optics Letters》 SCIE EI CAS CSCD 2020年第4期1-11,共11页
Space-division multiplexing(SDM)has attracted significant attention in recent years because larger transmission capacity is enabled by more degrees of freedom(DOFs)in few-mode fibers(FMFs)compared with singlemode fibe... Space-division multiplexing(SDM)has attracted significant attention in recent years because larger transmission capacity is enabled by more degrees of freedom(DOFs)in few-mode fibers(FMFs)compared with singlemode fibers(SMFs).To transmit independent information on spatial modes without or with minor digital signal processing(DSP),weakly-coupled FMFs are preferred in various applications.Several cases with different use of spatial DOFs in weakly-coupled FMFs are demonstrated in this work,including single-mode or mode-groupmultiplexed transmission,and spatial DOFs combined with time or frequency DOF to improve the system performance. 展开更多
关键词 MULTIPLEXING nonlinear optics fibers radio frequency photonics fiber optics links and subsystems few-mode fibers
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Influence of Internal Stresses in Few-Mode Fiber on the Thermal Characteristics of Regenerated Gratings 被引量:1
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作者 Nurul Asha MOHD NAZAL Kok Sing LIM +2 位作者 Yen Sian LEE Muhammad Aizi MAT SALIM Harith AHMAD 《Photonic Sensors》 SCIE EI CAS CSCD 2019年第2期162-169,共8页
The pre-treatment of few-mode fibers (FMFs) has been successfully done with CO2 laser The wavelength difference, AA between the two resonant wavelengths in the few-mode fiber Bragg grating (FMFBG) varies with temperat... The pre-treatment of few-mode fibers (FMFs) has been successfully done with CO2 laser The wavelength difference, AA between the two resonant wavelengths in the few-mode fiber Bragg grating (FMFBG) varies with temperature increment during the annealing process. The results show that the treated fibers with lower stresses have lower thermal sensitivity in △λ than that of non-treated fiber. However, the treated fibers produce FMFBGs with better thermal durability and regeneration ratio. It is conceived that the presence of those stresses in the pristine fiber is responsible for the high thermal sensitivity in △λ. The thennal relaxation of stresses and structural rearrangement during the thennal annealing process are responsible for the degradation of the strength and resilience of the regenerated grating. 展开更多
关键词 Regenerated fiber BRAGG grating few-mode fiber thermal stress RELAXATION CO2 laser annealing thennal RESILIENCE
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All-fiber linear polarization and orbital angular momentum modes amplifier based on few-mode erbium-doped fiber and long period fiber grating 被引量:2
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作者 Jianfei Xing Jianxiang Wen +4 位作者 Jie Wang Fufei Pang Zhenyi Chen Yunqi Liu Wingyun Wang 《Chinese Optics Letters》 SCIE EI CAS CSCD 2018年第10期14-17,共4页
A few-mode erbium-doped fiber(FM-EDF) is fabricated using modified chemical vapor deposition in combination with liquid solution. The core and cladding diameters of the fiber are approximately 19.44 and 124.12 μm,r... A few-mode erbium-doped fiber(FM-EDF) is fabricated using modified chemical vapor deposition in combination with liquid solution. The core and cladding diameters of the fiber are approximately 19.44 and 124.12 μm,respectively. The refractive index difference is 0.98%, numerical aperture(NA) is 0.17, and normalized cut-off frequency at 1550 nm is 6.81. Therefore, it is a five-mode fiber, and can be used as a higher-order mode gain medium. Furthermore, a long period fiber grating(LPFG) is fabricated, which can convert LP〈01 mode to LP11 mode, and its conversion efficiency is up to 99%. The first-order orbital angular momentum(OAM) is also generated by combining the LPFG and polarization controller(PC). Then, an all-fiber amplification system based on the FM-EDF and LPFG, for LP11 mode and first-order OAM beams, is built up. Its on-off gain of the LP11 mode beam is 37.2 d B at 1521.2 nm. The variation, whose transverse mode field intensity of first-order OAM is increased with the increase of pumping power, is obvious. These show that both the LP11 mode and first-order OAM beams are amplified in the all-fiber amplification system. This is a novel all-fiber amplification scheme,which can be used in the optical communication fields. 展开更多
关键词 EDF All-fiber linear polarization and orbital angular momentum modes amplifier based on few-mode erbium-doped fiber and long period fiber grating OAM
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50 GHz optical true time delay beamforming in hybrid optical/mm-wave access networks with multi-core optical fiber distribution 被引量:2
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作者 álvaro Morales Idelfonso Tafur Monroy +1 位作者 Fredrik Nordwall Tommi Sφrensen 《Chinese Optics Letters》 SCIE EI CAS CSCD 2018年第4期25-29,共5页
We propose and experimentally validate an optical true time delay beamforming scheme with straightforward integration into hybrid optical/millimeter(mm)-wave access networks. In the proposed approach, the most compl... We propose and experimentally validate an optical true time delay beamforming scheme with straightforward integration into hybrid optical/millimeter(mm)-wave access networks. In the proposed approach, the most complex functions, including the beamforming network, are implemented in a central office, reducing the complexity and cost of remote antenna units. Different cores in a multi-core fiber are used to distribute the modulated signals to high-speed photodetectors acting as heterodyne mixers. The mm-wave carrier frequency is fixed to 50 GHz(VBand), thereby imposing a progressive delay between antenna elements of a few picoseconds. That true time delay is achieved with an accuracy lower than 1 ps and low phase noise. 展开更多
关键词 MCF GHz optical true time delay beamforming in hybrid optical/mm-wave access networks with multi-core optical fiber distribution
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