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Misalignment considerations in laser diode to single-mode graded index fiber coupling via upside down tapered parabolic microlens on the circular core fiber Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-25 Ramkrishna Rakshit; Angshuman Majumdar; Sankar Gangopadhyay
We report the theoretical analysis of the coupling optics involving laser diode to single-mode circular core graded index fiber excitation via upside down tapered parabolic microlens on the fiber in presence of possible transverse and angular misalignments. We use the relevant ABCD matrix appropriate for such type of coupling device in order to prescribe analytical expressions of coupling efficiencies
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Design of two miniaturized and broadband polarization filters based on two types of square-lattice gold-filled photonic crystal fibers Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-21 Linghong Jiang; Chao Wang; Jinhong Zou; YinPu Zhang; Yuefeng Qi; Wei Wang; Lantian Hou
Two ultra-broadband polarization filters based on Structure 1 and Structure 2 are reported and characterized in terms of attenuation, crosstalk, bandwidth, and polarization filtering properties by the finite element method. Structure 1 is formed by introducing partial elliptical air holes in the first layer of the square-lattice gold-filled photonic crystal fiber. Based on the design solution of Structure
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Joint OSNR monitoring and modulation format identification on signal amplitude histograms using convolutional neural network Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-21 Hongjing Lv; Xian Zhou; Jiahao Huo; Jinhui Yuan
A joint optical signal-to-noise ratio (OSNR) monitoring and modulation format identification (MFI) is proposed based on signal amplitude histograms (AHs) by using convolutional neural network (CNN). By the use of the proposed scheme, the OSNR monitoring accuracy can be achieved 97.6%, 100%, and 100% for 28GBaud QPSK, 8-QAM, and 16-QAM respectively within a wide OSNR range (10–26 dB). Similarly, the
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Characterization and calibration of shape sensors based on multicore optical fibre Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-18 Ravil Idrisov; Ignazio Floris; Manfred Rothhardt; Hartmut Bartelt
In order to provide high accuracy in shape measurement with multicore optical fibres, characterization and calibration procedures are an important part of sensor preparation. Some procedures can be considered mandatory for adequate shape reconstruction, while others can help to enhance the measurement accuracy. Several of such procedures are discussed and experimentally applied for demonstrating the
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High order modes suppression and manipulation in six-holes helical chiral microstructure fiber Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-18 Jialong Li; Boyao Li; Changming Xia; Zhiyun Hou; Guiyao Zhou
We experimentally report a high-order-mode (HOM) suppression effect which may bring dips in transmission spectrum of a large-size (with core diameter > 10 µm) six-hole helical microstructured fiber (HMSF). Firstly, we performed rigorous theoretical analysis in helical frame to demonstrate that high loss peaks do not appear in fundamental mode. However, this phenomenon suppressed at special wavelengths
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Generation of H-shaped pulse rains induced by intracavity Fabry–Perót filtering in a fiber laser Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-17 Yinbin He; Mengxian Li; Yiqing Shu; Qiuyi Ning; Weicheng Chen; Aiping Luo
We report the generation of h-shaped pulses and rains in a fiber laser with a Fabry–Perót (F–P) subcavity. An h-shaped pulse state composed of a sharp spike as a leading edge and a long flat-top bunch as a tailing one could be switched to an h-shaped pulse rain state by adjusting the polarization controllers (PCs). F–P filtering was found to play a crucial role in the formation of the h-shaped pulses
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Single-mode fiber auto-coupling system with wedges Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-08 Bingsong Cao; Zhifang Qiu; Kaikai Huang; Desheng Lü; Xian Zhang; Xuanhui Lu
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High sensitivity refractive index sensor in long-range surface plasmon resonance based on side polished optical fiber Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-08 Rozalina Zakaria; NurAina'a Mardhiah Zainuddin; Muhammad Aiman Saufi Ahmad Fahri; Punithavathi M. Thirunavakkarasu; Shobhit K. Patel; Sulaiman Wadi Harun
A side-polished single mode optical fiber based on conventional long-range surface plasmon resonance (cLRSPR) sensor and symmetrical long-range surface plasmon resonance (sLRSPR) sensor was proposed and experimentally demonstrated. The proposed structure of cLRSPR is composed of optical fiber/dielectric buffer layer (DBL)/Ag film while for sLRSPR is consisted of optical fiber/DBL/Ag film/DBL. Magnesium
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Quad-ring based erbium fiber laser for switchable and stable single-longitudinal-mode operation Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-07 Chien-Hung Yeh; Li-Hung Liu; Han-Shin Ko; Bo-Yin Wang; Wei-Hung Hsu; Chi-Wai Chow; Jing-Heng Chen
To accomplish single-longitudinal-mode (SLM) output and continuous wavelength selection, an erbium-doped fiber (EDF) quad-ring (QR) laser is presented and experimentally examined. The designed QR scheme can induce a mode-filter effect to compress dense multi-mode oscillation, narrow laser linewidth and flatten power output simultaneously. Hence, the attained optical signal to noise ratio (OSNR) and
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Fair and efficient DWBA algorithm based on SLA differentiated polling interleaved scheduling for NG-EPON Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-08 Yifan Li; Chen Qian; Qianwu Zhang; Min Wang
This study, based on the Next Generation Ethernet Passive Optical Network (NG-EPON) facing more complex and changeable network, develops a flexible and efficient resource allocation algorithm. First, a differentiated polling interleaved scheduling (DPIS) framework is designed based on dynamic awareness, significantly reducing idle time slots, improving channel upstream utilization, and performing
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A two-dimensional cantilever beam vibration sensor based on fiber Bragg Grating Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-07 Zhen'an Jia; Xianfeng Zhao; Wei Fan; Hong Gao; Qinpeng Liu; Zhen Yong; Yinggang Liu; Kaiqing Yang
A two-dimensional cantilever vibration sensor based on Fiber Bragg Grating (FBG) is proposed. The proposed sensor consists of a section of optical fiber with double FBGs and three different beams. After theoretical analysis and experimental verification, the proposed sensor has a high sensitivity response. The experimental result shows that the natural frequency of the sensor in the x/y direction of
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8-Hydroxyquinolino cadmium chloride hydrate for generating nanosecond and picosecond pulses in erbium-doped fiber laser cavity Opt. Fiber Technol. (IF 2.212) Pub Date : 2021-01-06 Mustafa Mohammed Najm; Sulaiman Wadi Harun; Sameer Salam; Hamzah Arof; B. Nizamani; M. Yasin
In this paper, we experimentally proposed and demonstrated the application of thin-film saturable absorber (SA) based on 8-Hydroxyquinolino cadmium chloride hydrate (8-HQCdCl2H2O) material as both Q-switcher and mode-locker in the cavity of erbium-doped fiber laser (EDFL). The 8-HQCdCl2H2O was embedded in polyvinyl alcohol (PVA) to fabricate the thin-film, which has then employed in the Q-switched
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Study on the clay weakening characteristics in deep unconsolidated layer using the multi-point monitoring system of FBG sensor arrays Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-30 Yi-Wei Ren; Qiang Yuan; Jing Chai; Yong-Liang Liu; Ding-Ding Zhang; Xian-Wei Liu; Yan-Xin Liu
A large area of thick unconsolidated stratum layer overlying the coal seam of eastern China, which brought the regional disaster prevention issue under the circumstance of unconsolidated layer settlement triggered by mining activities. In this paper, the multi-point monitoring system based on fiber Bragg grating (FBG) sensors array was implemented into the deep unconsolidated layer to realize a long-term
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Generation of Q-switched fiber laser at 1.0-, 1.55- and 2.0-µm employing a spent coffee ground based saturable absorber Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-31 Muhammad Farid Mohd Rusdi; Afiq Arif Aminuddin Jafry; Anas Abdul Latiff; Ahmad Haziq Aiman Rosol; Mohd Fauzi Ab Rahman; Nabilah Kasim; Muhammad Imran Mustafa Abdul Khudus; Harith Ahmad; Sulaiman Wadi Harun
Spent coffee ground (SCG) was demonstrated as saturable absorber (SA) for Wideband Q-switched fiber lasers generation. The SCG SA has a broad linear absorption that covers from 1000 nm to 2000 nm wavelength and a modulation depth of 30% at 1.55-µm region. Through purification process, the finer SCG powder is obtained, and be embedded with a polyvinyl alcohol for thin film formation. To realize Q-switching
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Study on bridge weigh in motion (BWIM) system for measuring the vehicle parameters based on strain measurement using FBG sensors Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-31 Sravanthi Alamandala; R.L.N. Sai Prasad; Rathish Kumar Pancharathi; V.D.R. Pavan; P. Kishore
A Weigh in Motion (WIM) system is proposed, employing two fiber Bragg grating (FBG) sensors to evaluate the strain at a point on a prototype bridge due to a moving vehicle. The FBG's are fixed at two different longitudinal girders of bridge along the line of motion at different orientations. The parameters of investigation include strain developed in the proximity of FBG’s and speed of the vehicle
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Lasing characteristics of highly bend compensated large mode area ytterbium doped modified hybrid multi trench fiber Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-31 N. Ayyanar; G. Thavasi Raja
In this article, lasing characteristics of a newly designed ytterbium-doped modified hybrid multi trench fiber (YDMHMTF) has been numerically investigated for strongly pumped conditions. The designed YDMHMTF is maintained single-mode condition with an effective mode area of 1300μm2 at the wavelength of 1064 nm for the compact bending radius of 7.5 cm. The radius of doped region is varied up to a maximum
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Deformation monitoring of cracked concrete structures based on distributed optical fiber sensing technology Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-31 Zi-xiang Li; Gong-yu Hou; Kai-di Wang; Jin-xin Hu
In recent years, distributed fiber optic sensing (DFOS) has been widely used for structural deformation monitoring. Conventional deformation monitoring methods using DFOS have a limitation in that they are based on the conventional assumptions in continuum mechanics such as uniformity and continuity. These methods are unsuitable for cracked concrete structures that exhibit discontinuity (discrete body)
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Fabrication of a stepped optical fiber tip for miniaturized scanners Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-30 Mandeep Kaur; Geoffrey Hohert; Pierre M. Lane; Carlo Menon
Advancements in fabrication of miniaturized optical scanners would benefit from micrometer sized optical fiber tips. The change in the cross section of an optical fiber tip is often accompanied with the presence of a longer tapered area. The reduction of the cross section of double clad optical fibers (DCFs) with a flat interface surface at the region where a change in the cross section takes place
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Simulation of fiber fuse phenomenon in photonic crystal fibers Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-28 Yoshito Shuto
The unsteady-state thermal conduction process in several photonic crystal fibers (PCFs) was studied theoretically by the explicit finite-difference method using the thermochemical SiOx production model. The threshold power Pth for fiber fuse propagation in these PCFs was one order of magnitude higher than that for conventional single-mode optical fibers (SMFs). These results agreed with the experimental
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Temperature sensor based on second-order PbS fiber Solc-Sagnac interferometer Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-24 Xinghu Fu; Shuming Huang; Dongshu Li; Jiangpeng Zhang; Guangwei Fu; Wa Jin; Weihong Bi; Qingsong Hu
In this paper, a temperature sensor based on a second-order PbS fiber Solc-Sagnac interferometer is presented. The PbS fiber and the two sections of single-mode fiber (SMF) are spliced together, it is named SMF-PbS-SMF structure. The light passes through the coupler and is divided into two beams of equal power, which are propagated in the Sagnac loop and travel through the two PbS fibers. The interference
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RGB wavelength multiplexer based on polycarbonate multicore polymer optical fiber Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-24 Bar Gelkop; Linoy Aichnboim; Dror Malka
One of the common techniques to increase data bitrate using visible light communication (VLC) fibers system is to use wavelength division multiplexing (WDM). However, the implementation of WDM requires additional devices and more power consumption which can limit the system performances. To overcome these problems, we propose a new approach for designing an RGB multiplexer based on multicore polymer
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Design and analysis of a photonic crystal fiber supporting stable transmission of 30 OAM modes Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-22 Linlin Zhang; Yichao Meng
In this paper, a new circular photonic crystal fiber (PCF) is designed, which can support stable transmission of 30 orbital angular momentum (OAM) modes. It is composed of 4 rings of air holes in the cladding and a large air hole in the center. The numerical results show that the fiber has good features. In the wavelength range of 1.35–1.8 μm, dispersion variations are less than 27.99 ps/nm/km when
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Impairment-aware spectrum allocation in elastic optical networks: A dispersion-sensitive approach Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-22 Bijoy Chand Chatterjee; Norvald Stol; Eiji Oki
The degradation of quality-of-transmission (QoT) due to the dispersion effect is a critical issue in elastic optical networks (EONs). To satisfy the required quality of transmission, a robust modulation level needs to be adopted. Thus, the number of required slots for spectrum allocation is increased. Although dispersion compensation devices reduce the effect of dispersion, they require an additional
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Heuristic planning algorithm for sharing restoration interfaces in OTN over DWDM networks Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-22 A.V.S. Xavier; J.C. Silva; J.F. Martins-Filho; C.J.A. Bastos-Filho; D.A.R. Chaves; R.C.A. Almeida Jr.; D.R.B. Araujo; J.A. Martins
Due to the expansion of telecommunication services, the demand for technologies that improve transmission quality has been growing in recent years. One of these technologies is optical transport networks (OTNs), which works as a layer above the DWDM (Dense Wavelength Division Multiplexing) network to enable the most efficient use of resources. This work proposes an OTN network planning solution over
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Realizing high adjustability of bandwidth and energy of output pulse in a self-similar femtosecond fiber laser Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-22 Atoosa Sadat Arabanian; Mahdi Salmanian
Numerical solving of nonlinear Schrödinger equation is performed for a self-similar femtosecond fiber laser cavity in order to investigate the effect of its key parameters (e.g., output coupling rate, net dispersion of cavity, and modulation depth) on the energy and the spectral bandwidth of output pulse in the stable mode-locking state. The calculations indicate that by decreasing the output coupling
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In-band OSNR monitoring for PDM-mQAM signals using directly detected Stokes parameters Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-21 Tonghui Ji; Yunfeng Peng; Xingyun Xu; Guojun Zhu; Jingjing Geng
In this paper, we propose an in-band optical signal-to-noise ratio (OSNR) monitoring method based on support vector machine (SVM). This method is tailored for the analysis of polarization-division multiplexing (PDM) m-ary quadrature amplitude modulation (m-QAM) signals. OSNR-related features are extracted from the numerical characteristics of Stokes parameters, while modulation-order related features
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Hybrid FSO/fiber optic link based reliable & energy efficient WDM optical network architecture Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-21 Amit Kumar Garg; Vijay Janyani; Bostjan Batagelj; N.H. Zainol Abidin; M.H. Abu Bakar
Nowadays, free space optics (FSO) is becoming popular and is very competitive to the fiber optic technology for providing broadband services at very high data rates without the requirement of any spectrum licensing. FSO links can be installed within a few hours and at a very low cost. As compared to the optical fiber, FSO links do not have any problem of faults during digging and maintenance of roads
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Wavelength tunable fiber Bragg gratings fabricated by stress annealing assisted femtosecond laser direct writing Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-20 Xiaoyan Sun; Zikun Chang; Li Zeng; Xinran Dong; Youwang Hu; Ji'an Duan
The resonant wavelength is an important parameter of fiber Bragg grating (FBG). When FBGs are fabricated by femtosecond (fs) laser direct writing, it can be fine-tuned through the process of stress annealing. By changing applied stress, it can be permanently fine-tuned in the range of 20.76 nm relative to the original one, and the tunable sensitivity is 1.48 nm/MPa. Besides, the elastic limit strength
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Rayleigh Φ-OTDR based DIS system design using hybrid features and machine learning algorithms Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-19 Ramji Tangudu; Prasant Kumar Sahu
There is an increasing interest among the researcher community, and industries on the design, and development of a combined distributed acoustic sensing, and a pattern recognition system to detect, and classify potentially dangerous intrusion events. In this work, we describe the design, and optimization of a distributed intrusion sensing system using Rayleigh-phase sensitive optical time domain reflectometry
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Design and simulation of a novel fungus-shaped center embossed diaphragm for fiber optic pressure sensors Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-19 Şekip Esat Hayber; Umut Aydemir
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Experimental investigation of a strain gauge sensor based on Fiber Bragg Grating for diameter measurement Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-18 Victor H.R. Cardoso; Paulo Caldas; M. Thereza R. Giraldi; Orlando Frazão; Claudio J. Reis de Carvalho; João C.W.A. Costa; José L. Santos
A strain gauge sensor based on Fiber Bragg Grating (FBG) for diameter measurement is proposed and experimentally demonstrated. The sensor is easily fabricated inserting the FBG on the strain gauge—it was fabricated using a 3D printer—and fixing the FBG in two points of this structure. The idea is to vary the diameter of the structure. We developed two experimental setups, the first one is used to evaluate
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Study on establishing and testing for strain transfer model of distributed optical fiber sensor in concrete structures Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-18 Zi-xiang Li; Gong-yu Hou; Tao Hu; Tian-ci Zhou; Hai-lin Xiao
When using distributed optical fibers for structural health monitoring, in order to ensure the survival rate of the optical fibers, it is usually necessary to insert the optical fibers into the structure for protection. The coupling performance between the optical fibers and the structure determines the accuracy of the monitoring results. In order to explore the strain transfer law of optical fibers
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Complex optical fiber sensor based on the Vernier effect for temperature sensing Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-17 Fulu Liu; Yumin Zhang; Fanyong Meng; Mingli Dong; Lianqing Zhu; Fei Luo
The Vernier effect is an effective way of magnifying the sensitivity of the sensor for higher resolution sensing. The Fiber-optic cascaded Fabry-Perot Interferometric (CFPI) temperature sensor has been theoretically studied and experimentally investigated in this paper base on Vernier effect. It has been manufactured by a segment of pure silica hollow-core fiber (HCF) fused between two sections single-mode
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The sparsity of the response of a quasi-distributed fiber optic sensing system allows ‘overclocking’ its interrogation Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-17 Nadav Arbel; Maya Yanko; Avishay Eyal
The response of a quasi-distributed fiber optic sensing system to a short interrogation pulse can be considered as a sparse signal in the time domain. This attribute can be exploited to enhance its performance beyond the commonly accepted limits. The work described here is analogous to some compressed sensing systems, which can be adequately sampled at sub-Nyquist rates, based on knowledge of their
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An optical fiber sensor based on polyimide coated fiber Bragg grating for measurement of relative humidity Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-16 Jianxin Zhang; Xueyun Shen; Miao Qian; Zhong Xiang; Xudong Hu
Humidity is an important parameter in many industry fields and accurate humidity measurement is of great significance to improve production efficiency and ensure product quality. This paper presents a sensing model and scheme for utilizing thermoplastic polyimide (PI) coated fiber Bragg grating (FBG). The humidity sensitive PI layer was firstly prepared and coated on the FBG. The humidity calibration
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C band 112 Gb/s PAM4 signal transmission over 320 km with a quasi-linear double-side electro-absorption modulated laser (DS-EML) Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-16 Jiahao Huo; Mingwei Sun; Xian Zhou; Wei Huangfu; Jinhui Yuan; Huansheng Ning; Keping Long
The growing traffic demand in data center interconnections (DCIs) requires high-speed and low-cost transceivers that can flexibly adapt to different transmission distances up to 80 km or further. In this paper, based on the double-side electro-absorption modulated laser (DS-EML), we propose a transmitter with a fixed 90-degree phase rotation on one side of the DS-EML that can realize quasi-linear complex
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Broadband Fe3O4 nanoparticles saturable absorber for Q-switched fiber lasers Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-15 N. Li; H. Jia; M. Guo; J. Zhang; W.Y. Zhang; Z.X. Guo; M.X. Li; Z.X. Jia; G.S. Qin
We demonstrated passively Q-switched 1-, 1.5-, and 2-μm fiber lasers by exploiting ferroferric-oxide nanoparticles (FONPs) as a broadband saturable absorber (SA). FONPs were prepared by a method of thermal decomposition, and then were mixed with sodium carboxymethylcelluose (NaCMC) to form a FONPs film. The FONPs film was sandwiched between two fiber ferrules to fabricate the FONPs SA, which had a
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Research on simultaneous temperature and relative humidity measurement based on tapered PCF Mach-Zehnder interferometer Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-14 Jietong Zhang; Zhengrong Tong; Weihua Zhang; Yeming Zhao; Jiaxin Li
A Mach-Zehnder interferometer (MZI) based on tapered photonic crystal fiber (PCF) for simultaneous temperature and relative humidity (RH) is proposed. It consists of two sections of single-mode fiber (SMF) fused with a section of tapered PCF. The temperature and RH sensitivities are improved by adding a taper in the middle of the PCF. The experimental results show that the temperature sensitivities
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Multiple leaf-ringing based protection algorithm with spectrum defragmentation for multicast traffic in elastic optical network Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-10 Meiling Pan; Yang Qiu; Chuanwu Zhang
Elastic optical networks (EONs) have realized high-speed data transmission with attractively efficiency and flexibility in resource utilization. In order to guarantee the reliability and increase the efficiency of the multicast transmission in EONs, we propose a multiple leaf-ringing based protection algorithm with spectrum defragmentation (MLRP-SD) in this article. The proposed algorithm firstly sorts
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Modes power equalization based-singular value decomposition in mode division multiplexing systems for multi-hungry bandwidth applications Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-09 Yousef Fazea; Angela Amphawan; Y.A. Al-Gumaei; Ahmed M. Al-Samman; Waleed Mugahed Al-Rahmi
Optical fiber tendencies are pushing for changes towards upgrading scalability, agility, and unwavering quality for multi-hungry bandwidth applications. In the quest for future proof of those multi-hungry bandwidth applications, is vital to take advantage of new multiplexing technologies as the surge of network traffic that soon will overwhelm the capacity of multimode fiber (MMF). Due to the issue
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A ROF system based on 18-tuple frequency millimeter wave generation using external modulator and SOA Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-07 Hui Zhou; Chuyuan Fei; Yuting Zeng; Yuan Tan; Ming Chen
In this paper, we have reported a radio-over-fiber (ROF) system with 18-tuple frequency optical millimeter-wave using external modulator and four-wave mixing (FWM) in semiconductor optical amplifier (SOA). Signal lightwave and pump with frequency interval of 6fRF are generated by adjusting the parameters of the Mach-Zehnder modulator (MZM). After FWM in SOA and filtering, 18-tuple frequency millimeter-wave
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Study on a health monitoring and defect imaging technology of special equipment that is based on optical fiber ultrasonic sensing Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-05 Zijie Zou; Zhongbao Qin; Yiyi Li; Qi Liu
Special equipment is prone to crack damage due to long-term pressure bearing during service. If the cracks in the structure are not detected in time and maintenance work is conducted, severe safety risks will be incurred. To overcome these problems, it is necessary to conduct full-time and full-domain structural on-line monitoring for special equipment to effectively prevent cracking of the special
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Research on frequency stability of narrow linewidth laser in resonant optical gyro Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-05 Kang Zou; Ran Bi; Kan Chen; Xuan She; Caini Zhang; Xiaowu Shu
In this study, to measure the frequency drift characteristics of the narrow-linewidth laser, we provide a method with high accuracy and adjustable measuring range that can be applied in a resonant optical gyro (ROG) system. In an ROG system, the laser frequency drift characteristics, such as fluctuation range and frequency, influence the performance of the closed-loop frequency-locked module. To measure
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Probabilistic shaping with pre-equalization in W-band MM-wave communication system with heterodyne coherent detection Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-12-01 Li Zhao; Rui Zhang; Wen Zhou; Shuyi Shen; Jiangnan Xiao; G.K. Chang; Jianjun Yu
In this paper, an 85 GHz MM-wave signal is demonstrated in the fiber and MM-wave converged system in W-band. It is known to us, this is the first experimental demonstration that the pre-equalizaiton (PE) and probabilistic shaping (PS) techniques are applied to the fiber and MM-wave converged system. BER of 4.4 × 10−3 is achieved by using those method after 4-m wireless transmission and 25-km Standard
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A multi-repeat mapping based probabilistic shaping coding method applied to data center optical networks Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-30 Zexuan Jing; Qinghua Tian; Xiangjun Xin; Junjie Ding; Jianjun Yu; Xiaolong Pan; Qi Zhang; Lei Zhu; Feng Tian; Yongjun Wang; Ran Gao
In recent years, the technology to narrow the gap between the achievable information rate and the Shannon capacity limits attracts increasing attention. In this paper, a probabilistic shaping coding method based on multi-repeat mapping is proposed. By applying block coding to the information sequences with our method, we transform the modulated constellation points from a uniform distribution to the
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Ultra-sensitive gas pressure sensor based on vernier effect with controllable amplification factor Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-29 Qiao Han Wang; Xin Liu; D.N. Wang
We present an optical fiber gas pressure sensor based on two cascaded Fabry-Perot interferometer cavities, one is a section of capillary tube spliced with single mode fiber at its two ends and the other consists of a pair of in-fiber reflection mirrors inscribed by use of femtosecond laser micromachining. The cavity length difference of the two Fabry-Perot interferometers can be precisely controlled
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Refractive index and temperature sensor based on fiber ring laser with tapered seven core fiber structure in 2 μm band Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-25 Ying Wang; Zhihao Chen; Weijuan Chen; Xianzeng Zhang
A weakly-coupled taper-based seven core fiber (TSCF) structure sensor for refractive index (RI) and temperature measurement with a fiber ring cavity laser in 2 μm band was proposed and demonstrated. The TSCF fiber structure acts as both the sensing head and the filter of the laser. Compared with the conventional broadband sensing system, the laser sensing system we proposed has a higher optical signal
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Combined phase offset channel estimation method for optical OFDM/OQAM Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-25 Xi Fang; Zhufeng Suo; Lei Zhang; Qingchuan Zhang; Fan Zhang
On the basis of coherent optical orthogonal frequency-division-multiplexing (CO-OFDM), CO-OFDM/ offset quadrature amplitude modulation (CO-OFDM/OQAM) improves the spectrum efficiency by utilizing specially designed filter banks to eliminate the cyclic prefix (CP) inserted between consecutive OFDM blocks and decreases the demanding of guard band between two channels, being a promising candidate for
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Stabilization of high sensitivity optical fiber AE sensing for long-term detection Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-23 Zhaozhu Liu; Xuezhi Zhang; Junfeng Jiang; Kun Liu; Shuang Wang; Boyue Yang; Tiegen Liu
The optical fiber acoustic emission (AE) sensing system with high sensitivity is stabilized for long-term detection in this paper. The high linear slope window of the phase-shifted fiber Bragg grating (PS-FBG) spectrum is tracked by the tunable laser source (TLS) to maintain high AE detection sensitivity. The experimental results show that the proposed method successfully solves the problem of PS-FBG
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High-precision calibration method for fiber Bragg grating strain sensing based on an optical lever Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-21 Ruoshui Tan; Chen Chen; Yongqiu Zheng; Jiamin Chen; Liyun Wu
The high-precision strain calibration of a fiber Bragg grating (FBG) is critical to the engineering application of fiber grating sensors. In this paper, a strain calibration method based on the optical lever is proposed for the FBG sensor. The optical lever is used to measure a tiny displacement through optical amplification. Comparing with traditional strain calibration using a beam structure and
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QoS-aware protection in elastic optical networks with distance-adaptive and reconfigurable modulation formats Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-13 Dao Thanh Hai; Hoang Trong Minh; Le Hai Chau
Elastic optical networks have recently emerged as one of the most promising technologies for creating next-generation optical core networks thanks to the adaptive spectrum allocation mechanism. In order to achieve higher spectrum efficiency and exploit elastic optical networking technology, in this paper, we introduce a novel perspective on re-designing dedicated path protection for elastic optical
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Simulation and hardware implementation of demodulation for fiber optic seismic sensor with linear edge filtering method Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-11 Rui Zhou; Hong Gao; Zhongyao Feng; Xueguang Qiao
The demodulation system is a very critical component of the seismic exploration, which determines the response speed and accuracy of data acquisition of the detection system. Here, we demonstrate a simulation and hardware implementation of demodulation system based on linear edge filtering method for fiber optic seismic sensor. The system is implemented mainly by an edge filter (long period fiber grating)
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A novel bio-inspired optimization algorithm for solving peak-to-average power ratio problem in DC-biased optical systems Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-06 Hojjat Emami; Abbas Ali Sharifi
In this paper, a tree growth optimization (TGO) algorithm is introduced to diminish the computational complexity of the partial transmit sequence in exploring the optimal phase factors. The proposed TGO algorithm is an efficient method for reducing the high peak-to-average power ratio of optical orthogonal frequency division multiplexing signals. The problem of the peak-to-average power ratio causes
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All-fiber humidity sensor based on Michelson interferometer with hyaluronic acid and polyvinyl alcohol composite film Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-05 Xiaoting Sun; Huaping Gong; Mingyang Xie; Chun-Liu Zhao
All-fiber humidity sensor based on Michelson interferometer with hyaluronic acid (HA) and polyvinyl alcohol (PVA) composite film is investigated. The interferometer is fabricated by fusing 691 μm thin-core fiber (TCF) with single mode fiber (SMF) together and melting the other end of the TCF into a circular shape. The outer of the interferometer is coated with HA and PVA composite film. As far as we
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Analysis of deep multilayer perceptron neural network in MWC coded optical CDMA system with LDPC code Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-04 Chun-Ming Huang; Chao-Chin Yang; Eddy Wijanto; Hsu-Chih Cheng
In this paper, applying the Deep Multilayer Perceptron Neural Network (MLPNN) to the Sum-Product Algorithm (SPA) for decoding the Modified Welch-Costas (MWC) coded Optical Code Division Multiple Access (OCDMA) system with Low-Density Parity-Check (LDPC) code is analyzed. The goal is to train the MLPNN-SPA through the stochastic gradient descent (SGD) to learn and optimize the weights to each edge of
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Optical label switching based on Manchester code + NRZ modulation Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-05 Yang Lu; Yaoyao Wang; Linghuan Hu; Xun Du; Ju Li; Hang Li; Meihua Bi
Optical label switching (OLS) is regarded as one promising solution for the packet-based optical switching. In this paper, a novel modulation, i.e., Manchester code + NRZ modulation is proposed for OLS. The Manchester coded payload signal the NRZ label signal are combined and then modulated onto an optical carrier by only one ASK modulator. The Manchester coded payload signal and the NRZ label signal
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Optical weight measurement system using FBG based D-IM edge filter detection Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-05 Abhinav Gautam; Amitesh Kumar; Jaisingh Thangaraj; Devendra Chack; Vishnu Priye
Fiber Bragg Gratings (FBGs) are extensively used as strain and temperature sensors in various industrial applications. The key task for FBG based sensing system is to convert the optical sensing data into user friendly information that can be interpreted with ease. Edge filter detection (EFD) interrogation technique is commonly used to convert wavelength encoded sensing data into optical power variation
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Fabry-Perot vector curvature sensor based on cavity length demodulation Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-04 Fuxing Zhu; Yundong Zhang; Yanchen Qu; Huaiyin Su; Weiguo Jiang; Ying Guo; Kaiyue Qi
We have demonstrated a high-sensitivity Fabry-Perot curvature sensor. The main components of its sensing fiber are hollow silica tube and single-mode fiber (SMF). When the sensor is bent, the length of the FPI changes with curvature. Hereby, we can achieve vector curvature measurement through cavity length demodulation. The convex and concave bending sensitivities are 151.30 nm/m−1 and −333.89 nm/m−1
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An edge-filter FBG interrogation approach based on tunable Fabry-Perot filter for strain measurement of planetary gearbox Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-11-02 Xiaodong Zhang; Hang Niu; Chenggang Hou; Fagui Di
Fiber Bragg gratings (FBGs), with smaller size, are suitable to measure the tooth root strain of ring gear which is an ideal signal for fault diagnosis of planetary gearboxes. In order to identify the fault features in the strain signal, a high-speed and high-resolution FBG interrogator is needed. Compared with wavelength-scanning interrogation approach, the edge-filter approach can achieve such a
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Whole-process monitoring of sinkhole collapse based on distributed optical fiber strain-vibration joint system and its case study in railway subgrade Opt. Fiber Technol. (IF 2.212) Pub Date : 2020-10-29 Jianping He; Yuan Xue; Jun Xu; Dongqing Zhang; Shihai Zhang
Sinkhole is a unique geological disaster, which has the characteristics of concealment in space, accumulation in the development process and sudden collapse caused by roof instability, and the whole development process contains deformation and vibration information. This paper presents a distributed optical fiber strain-vibration joint system based on distributed optical fiber strain and vibration
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