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Temperature-Robust Monitoring of TDM-PONs Through optical coding Assisted by Broadband λ-Tunable I-OFDR

JOURNAL OF LIGHTWAVE TECHNOLOGY 2021年第14期39卷 4607-4613页

作者： Fernandez, Manuel P. Morbidel, Leonardo Bulus-Rossini, Laureano A. Costanzo-Caso, Pablo A. CNEA Lab Invest Aplicada Telecomunicac LIAT DIT GDTyPEGAIyANN RA-8400 San Carlos De Bariloche Rio Negro Argentina Inst Balseiro RA-9500 San Carlos De Bariloche Rio Negro Argentina

We present a technique for remote monitoring of time-division multiplexed passive optical networks (TDM-PONs) based on fiber Bragg grating (FBG) encoders interrogated by a broadband incoherent optical frequency-domain reflectometer (I-OFDR). Compared with previous approaches, the proposed system features inherent high robustness against temperature-induced wavelength shifts in the FBG-encoders. The I-OFDR-based monitoring unit enables measurements with high resolutions and sensitivities without the need for high peak-power monitoring signals, which minimizes its footprint on the data links. We carry out a comprehensive description of the system and we evaluate its capacity in terms of signal-to-interference ratio (SIR). We show that, through suitable windowing, a SIR >= 20 dB can be achieved in highly-dense TDM-PONs having more than 128 customers through the use of moderate measurement bandwidths of 300 MHz. We experimentally demonstrate the proposal in a TDM-PON carrying a 10 Gbps downstream data signals, obtaining a negligible impact in the downlink performance, such as the bit error rate remains below 10(-6).

关键词： Passive optical networks monitoring optical coding optical frequency-domain reflectometry

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Design and Performance Evalauation of an optical coding Scheme for PON Monitoring 16

Design and Performance Evalauation of an Optical Coding Sche...

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16th Workshop on Information Processing and Control (RPIC)

作者： Fernandez, Manuel P. Caso, Pablo A. Costanzo Rossini, Laureano A. Bulus UNCuyo Inst Balseiro CNEA Ave Bustillo 9500 Barioche RN Argentina

ISBN: (纸本)9781467384667

optical coding has numerous properties that make its application to remote monitoring and failure detection in passive optical networks very attractive. Several approaches for encoder implementation have been proposed. One of them consist of a couple of fiber Bragg gratings forming a cavity producing multi-level periodic codes. In this work we propose and evaluate the performance of two new encoder schemes based on this premise. These new encoders generate codes with Hamming weight 2 and 3 in order to improve the performance of multi-level periodic codes. We observe that the proposed coding schemes show a better performance under certain scenarios.

关键词： passive optical networks monitoring optical coding OCDMA

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A New Method for Monitoring GPON Based on optical coding

A New Method for Monitoring GPON Based on Optical Coding

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International Telecommunication Networks and Applications Conference

作者： Huda Saleh Abbas Mark A. Gregory RMIT University

ISBN: (纸本)9781467393492

Monitoring Passive optical Networks (PON) based on optical coding (OC) is a cost-effective monitoring technique. In a PON, the monitoring signals are transmitted on a dedicated band (U band) with data transmitted using a different band (L-band). This paper introduces a new method to monitor Gigabit Passive optical Networks based on an OC technique. The proposed method utilizes the information from the PON ranging process that is managed by the optical Line Terminal to specify a fixed delay time for transmissions to and from the optical Network Units. The paper shows that information about the link status can be extracted from the decoded signal.

关键词： GPON Monitoring optical coding Prime Code Ranging

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Spatial Hadamard Encoding with Difference Frequency Generation 23

Spatial Hadamard Encoding with Difference Frequency Generati...

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Conference on Nonlinear Frequency Generation and Conversion - Materials and Devices XXIII

作者： Xu, Yang Tang, Sirui Black, A. Nicholas Boyd, Robert W. Univ Rochester Dept Phys & Astron Rochester NY 14627 USA Univ Rochester Inst Opt Rochester NY 14627 USA Univ Ottawa Dept Phys Ottawa ON K1N 6N5 Canada Univ Calif Berkeley Dept Elect Engn Berkeley CA USA

ISBN: (纸本)9781510669994;9781510669987

Orthogonal optical coding is widely used in classical multi-user communication networks. Using the phase conjugation property of stimulated parametric down-conversion, we extend the current time-domain orthogonal optical coding scheme to the spatial domain to encode and decode image information. In this process, the idler beam inherits the complex conjugate of the field information encoded in the seed beam. An encoding phase mask introduced onto the input seed beam blurs the image transferred to the idler. The original image is restored by passing the coded transferred image through a corrective phase mask placed in the momentum space of the idler beam. We expect that this scheme can also inspire new techniques in secure image transmission, aberration cancellation, and frequency conversion imaging.

关键词： Nonlinear Optics optical coding

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Co-Assembly of Biosynthetic Chiral Nematic Adhesive Materials with Dynamic Polarized Luminescence

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SMALL 2022年第2期18卷 2104340-2104340页

作者： Kim, Minkyu Lee, Hansol Snipes, Randall T. Han, Moon Jong Tsukruk, Vladimir V. Georgia Inst Technol Sch Mat Sci & Engn Atlanta GA 30332 USA Clemson Univ Dept Mat Sci & Engn Clemson SC 29634 USA

There is currently an extensive demand for simple and effective synthetic methods to allow the design and fabrication of robust and flexible chiral materials that can generate strong and switchable circularly polarized luminescence (CPL). Herein, biosynthetic light-emitting adhesive materials based upon chiral nematic cellulose nanocrystal-polyelectrolyte complexes with universal high adhesion on both hydrophilic and hydrophobic substrates are reported. Strong and dynamic photoluminescence with highly asymmetric and switchable circular polarization is induced by minute rare earth europium doping without compromising adhesive strength and initial iridescent properties. The photoluminescence can be temporarily quenched with highly volatile acetone vapor and liquid followed by fast recovery after drying with full restoration of initial emission. The unique properties of light-emitting bio-adhesives with universal adhesion, amplified and dynamic photoluminescence, and large and switchable CPL can be utilized for security optical coding, bio-optical memory, hidden communication, and biochemical sensing as wearable stickers, prints, and tattoos to directly adhere to human clothes, gadgets, and skin by using adhesive stickers with bright tailored photoluminescence.

关键词： adhesive biopolyelectrolytes biomaterial nanocomposites cellulose nanocrystals dynamic circularly polarized luminescence optical coding photoluminescence amplification self-assembly and adhesion

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Geometric Super-resolution using Negative Rect Mask

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OPTIK 2018年 168卷 323-341页

作者： ul Haq, Ihtsham Mudassar, Asloob A. PIEAS DPAM Islamabad Pakistan Pakistan Council Sci & Ind Res NPSL Islamabad Pakistan

In an electronic imaging system, image is retrieved using a Charged Coupled Device (CCD). Its finite pixel size integrates the optical information and limits the spatial resolution, whereas pixel-pitch provides the sampling interval. Spatial resolution can be improved if pixels of smaller sizes are used or equivalently if Geometric Super-Resolution technique is achieved. In this paper, we are reporting use of the Negative rect mask (NRM) at image plane to achieve Geometric Super-resolution through sub-pixeling. The NRM is scanned over CCD in sub-pixel steps and image data is gathered. The target is assumed to be static during the scanning process. The data collected through CCD with NRM coding and the position information of the scanning mask provides a mean to render the geometrically super resolved image. The work is demonstrated in one and two dimensions with computer simulation. The results are also applicable on CMOS based imaging. (C) 2018 Elsevier GmbH. All rights reserved.

关键词： Geometric superresolution Spatial resolution CCD-pixel Subpixel Mask scanning optical coding Computational decoding optical image processing

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Extracting sub-exposure images from a single capture through Fourier-based optical modulation

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2018年 60卷 107-115页

作者： Khan, Shah Rez Feldman, Martin Gunturk, Bahadir K. Istanbul Medipol Univ Dept Elect & Elect Engn Istanbul Turkey Louisiana State Univ Div Elect & Comp Engn Baton Rouge LA 70803 USA

Through pixel-wise optical coding of images during exposure time, it is possible to extract sub-exposure images from a single capture. Such a capability can be used for different purposes, including high-speed imaging, high-dynamic-range imaging and compressed sensing. In this paper, we demonstrate a sub-exposure image extraction method, where the exposure coding pattern is inspired from frequency division multiplexing idea of communication systems. The coding masks modulate sub-exposure images in such a way that they are placed in non-overlapping regions in Fourier domain. The sub-exposure image extraction process involves digital filtering of the captured signal with proper band-pass filters. The prototype imaging system incorporates a Liquid Crystal over Silicon (LCoS) based spatial light modulator synchronized with a camera for pixel-wise exposure coding. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Computational photography optical coding Pixel-wise exposure control

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Mechanically Excited Multicolor Luminescence in Lanthanide Ions

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ADVANCED MATERIALS 2019年第7期31卷 1807062-1807062页

作者： Du, Yangyang Jiang, Yue Sun, Tianying Zhao, Jianxiong Huang, Bolong Peng, Dengfeng Wang, Feng City Univ Hong Kong Dept Mat Sci & Engn 83 Tat Chee Ave Hong Kong Peoples R China City Univ Hong Kong Shenzhen Res Inst Shenzhen 518057 Peoples R China Shenzhen Univ Coll Optoelect Engn Minist Educ & Guangdong Prov Key Lab Optoelect Devices & Syst Shenzhen 518060 Peoples R China Hong Kong Polytech Univ Dept Appl Biol & Chem Technol Hung Hom Hong Kong Peoples R China

Mechanoluminescence (ML) featuring photon emission by mechanical stimuli is promising for applications such as stress sensing, display, and artificial skin. However, the progress of utilizing ML processes is constrained by the limited range of available ML emission spectra. Herein, a general strategy for expanding the emission of ML through the use of lanthanide emitters is reported. A lithium-assisted annealing method for effective incorporation of various lanthanide ions (e.g., Tb3+, Eu3+, Pr3+, Sm3+, Er3+, Dy3+, Ho3+, Nd3+, Tm3+, and Yb3+) into CaZnOS crystals that are identified as one of the most efficient host materials for ML is developed. These doped CaZnOS crystals show efficient and tunable ML spanning full spectrum from violet to near infrared. The multicolor ML materials are used to create encrypted anticounterfeiting patterns, which produce spatially resolvable optical codes under single-point dynamic pressure of a ballpoint pen.

关键词： CaZnOS lanthanides mechanoluminescence multicolor tuning optical coding

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Efficient and costless monitoring mechanism in metro-access network

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optical SWITCHING AND NETWORKING 2017年 25卷 117-123页

作者： Cheng, Zijing Li, Xiao Ji, Wei Space Star Aerosp Technol Applicat Co Ltd Beijing Peoples R China Shandong Univ Sch Informat Sci & Engn 27 Shanda South Rd Jinan 250100 Shandong Peoples R China

Fast and unambiguous link or node failure localization is very important and necessary in optical network. But it is not always clear what constitutes a good method to monitor the whole network. In an effort to understand the benefits and drawbacks of existing methods, we empirically present two state-of-the-art methods: monitoring trails method and optical coding method for their ability of monitoring time, cost, scalability and centralized management performance. Then a new fault location method combining the advantages of two schemes in the mesh-tree network that can be used for metro-access network is introduced. At the same time, performance analysis of monitoring scheme is obtained. It can be seen that the proposed method can monitor the whole optical network effectively with low cost and good scalability. The technique can support high network capacity.

关键词： Monitoring Mesh-tree network optical coding Monitoring trail allocation (MTA) Fiber Bragg Grating (FBG)

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optical coding scheme for all-optical analog-to-digital conversion using asymmetrical Y-branch waveguide

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OPTICS COMMUNICATIONS 2011年第9期284卷 2298-2302页

作者： Tang, Xionggui Liao, Jinkun Lu, Rongguo Li, Heping Zhang, Xiaoxia Zhang, Lin Liu, Yongzhi Univ Elect Sci & Technol China Sch Optoelect Informat Chengdu 610054 Peoples R China

The novel optical coding scheme for all-optical analog-to-digital conversion has been proposed, in which asymmetrical Y-branch waveguide structures have been introduced to achieve the desired optical power splitting. The optical performance has been simulated by using finite-difference beam propagation method (FD-BPM), which shows that the designed component exhibits good coding performance. Experimentally, the optical coding component has been fabricated and measured. The optical power contrast between bit code 1 and Oat output port is more than 37 dB, and measured imbalance of output power is less than 1.5 dB for bit code 1. (C) 2011 Elsevier B.V. All rights reserved.

关键词： optical coding All-optical analog-to-digital conversion Asymmetrical Y-branch waveguide

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