Effective 100 Gb/s IM/DD 850-nm Multi- and Single-Mode VCSEL Transmission Through OM4 MMF

To cope with the ever increasing data traffic demands in modern data centers, new approaches and technologies must be explored. Short range optical data links play a key role in this scenario, enabling very high speed data rate links. Recently, great research efforts are being made to improve the performance of vertical-cavity surface-emitting lasers (VCSELs) based transmission links, which constitute a cost-effective solution desirable for massive deployments. In this paper, we experimentally demonstrate intensity-modulation direct-detection transmissions with a data rate of 107.5 Gb/s over 10 m of OM4 multimode fiber (MMF) using a multimode VCSEL at 850 nm, and up to 100 m of OM4 MMF using a single-mode VCSEL at 850 nm. Measured bit error rates were below 7% overhead forward error correction limit of 3.8e−03, thus, achieving an effective bit rate of 100.5 Gb/s. These successful transmissions were achieved by means of the multiband approach of carrierless amplitude phase modulation. To cope with the ever increasing data traffic demands in modern data centers, new approaches and technologies must be explored. Short range optical data links play a key role in this scenario, enabling very high speed data rate links. Recently, great research efforts are being made to improve the performance of vertical-cavity surface-emitting lasers (VCSELs) based transmission links, which constitute a cost-effective solution desirable for massive deployments. In this paper, we experimentally demonstrate intensity-modulation direct-detection transmissions with a data rate of 107.5 Gb/s over 10 m of OM4 multimode fiber (MMF) using a multimode VCSEL at 850 nm, and up to 100 m of OM4 MMF using a single-mode VCSEL at 850 nm. Measured bit error rates were below 7% overhead forward error correction limit of 3.8e-03, thus, achieving an effective bit rate of 100.5 Gb/s. These successful transmissions were achieved by means of the multiband approach of carrierless amplitude phase modulation

LASER Tech Briefs, Winter 1994

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, Life Sciences, and Books and report

Multimode fibre broadband access and self-referencing sensor networks

Future Internet Access technologies are supposed to bring us a very performing connection to the main door of our homes. At the same time, new services and devices and their increase use will require data transfers at speeds exceeding 1Gbps inside the building or home at the horizon 2012. Both drivers lead to the deployment of a high-quality, futureproof network inside buildings and homes. This environment may end up taking advantage of optical cabling solutions as an alternative to more traditional copper or pure wireless approaches. Related to this latter fact, the objectives of this work are: • The achievement of a full convergence scenario between optical networks from the telecommunication services providers to the end users underscores the necessity of accurate and realistic fibre models in assessing the performance of broadband access networks with the premises of high-capacity and total compatibility. Silicabased MMFs and PF GIPOFs are the most promising candidates for such a convergence within the in-building/home scenario. Contributions to a better understanding of the possibilities of signal transmission outside the baseband of such fibres are investigated, in order to extend their capabilities, together with the evaluation of current fibre frequency response theoretical models by means of an extensive set of measurements. • The achievement of a full convergence scenario between optical networks from the telecommunication services providers to the end users is also contingent on research and development in the field of optical fibre sensors, mainly driven by the growing demand of fully building/home and industry automation, leading to a reliable integration of the optical networks. Related to this, development of multiplexing and measurement techniques for fibre-optic intensity-based sensors are analyzed and experimentally investigated. In the sensor network topology proposed, by replacing the fibre delay line with an electronic delay in the reception stage, it is possible to avoid long fibre delay coils in the remote sensing points and achieving a compact, flexible and re-configurable self-referencing technique. Applications in both scenarios can be considered, on the one hand the in-building/home network and on the other hand the WDM-PON access network topology through which operators provision the different services. -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------La demanda e incursión en la sociedad de nuevos servicios multimedia, tales como televisión por Internet (IPTV, Internet Protocol Television) o video-bajo-demanda (VoD, Video on Demand) junto con el incremento del tráfico de datos requerido para nuevas aplicaciones como la televisión por alta definición (HDTV, High-Definition Television) y transferencias P2P (Peer-to-Peer) exigen un aumento de la capacidad de las redes de datos desplegadas hoy en día. Para hacer frente a este aumento de la demanda de capacidad de las redes de acceso, los proveedores de estos servicios multimedia están reemplazando las infraestructuras de las redes de acceso basadas en cable coaxial, tales como xDSL (x- Digital Subscriber Line), por otras nuevas de mayor capacidad desplegadas en fibra óptica, permitiendo la interconexión de los nodos de red con los múltiples hogares y negocios de los abonados, constituyendo el núcleo de lo que es conocido como “fibra hasta el hogar/nodo/edificio” o redes FTTx. Tradicionalmente el despliegue de las redes ópticas se ha realizado mediante fibra óptica monomodo de sílice (SMF, Singlemode Fibre). Ello es debido a su gran ancho de banda que permite una gran capacidad de transporte de servicios y datos. Es por ello que en base a este tipo de fibra se ha realizado el despliegue de redes de distribución y metropolitanas y, de un tiempo a esta parte, incluso penetrando su instalación en las redes de acceso. Junto con lo anteriormente expuesto, existe una necesidad de convergencia de servicios e infraestructuras dentro de las redes de acceso. Actualmente, cables coaxiales, par trenzado de cobre e incluso señales inalámbricas se encuentran entremezcladas dentro del hogar proporcionando servicios diferentes con apenas cooperación entre ellos. Una infraestructura común dentro del hogar en el que una gran cantidad de servicios pudieran ser integrados y soportados por la misma sería un aspecto deseable. Y es más, frente a las desventajas de infraestructuras basadas en cable de cobre (cable coaxial y par trenzado) como son susceptibilidad a interferencias electromagnéticas, presencia de crosstalk y relativa baja capacidad de transporte de datos, las fibras ópticas (tanto en su versión monomodo como multimodo) presentan las ventajas de un menor volumen, mayor flexibilidad y menor peso junto con una capacidad mayor de transmisión de datos sobre distancias mayores. Es por esto que éstas últimas constituyen la base para las futuras redes de acceso en el hogar

Recent Progress in Optical Fiber Research

This book presents a comprehensive account of the recent progress in optical fiber research. It consists of four sections with 20 chapters covering the topics of nonlinear and polarisation effects in optical fibers, photonic crystal fibers and new applications for optical fibers. Section 1 reviews nonlinear effects in optical fibers in terms of theoretical analysis, experiments and applications. Section 2 presents polarization mode dispersion, chromatic dispersion and polarization dependent losses in optical fibers, fiber birefringence effects and spun fibers. Section 3 and 4 cover the topics of photonic crystal fibers and a new trend of optical fiber applications. Edited by three scientists with wide knowledge and experience in the field of fiber optics and photonics, the book brings together leading academics and practitioners in a comprehensive and incisive treatment of the subject. This is an essential point of reference for researchers working and teaching in optical fiber technologies, and for industrial users who need to be aware of current developments in optical fiber research areas

NASA Tech Briefs, February 1997

Topics include: Test and Measurement; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Report

Research Proposal for an Experiment to Search for the Decay {\mu} -> eee

We propose an experiment (Mu3e) to search for the lepton flavour violating decay mu+ -> e+e-e+. We aim for an ultimate sensitivity of one in 10^16 mu-decays, four orders of magnitude better than previous searches. This sensitivity is made possible by exploiting modern silicon pixel detectors providing high spatial resolution and hodoscopes using scintillating fibres and tiles providing precise timing information at high particle rates.Comment: Research proposal submitted to the Paul Scherrer Institute Research Committee for Particle Physics at the Ring Cyclotron, 104 page

The development of novel passive and active photonic-crystal devices

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (p. 158-169).Photonic crystals are anticipated to have impact on large-scale photonic integrated circuits by allowing the creation of compact and efficient devices such as waveguides, splitters, microcavity filters, light emitting diodes, and lasers. Previous experimental research has mainly focused on photonic crystals composed of a lattice of air holes etched into dielectric slabs. This thesis discusses the design, fabrication, and characterization of the "inverse" structure, a square lattice of dielectric-rods in air. Bandgap guiding of 1.5 lam light is experimentally demonstrated for a photonic-crystal waveguide created by introducing a line-defect of smaller-radii rods. To provide efficient optical coupling between input/output dielectric waveguides and the photonic-crystal waveguide, an adiabatic taper having two stages is employed. Furthermore, the thesis investigates novel photonic-crystal devices and fabrication schemes. An expose-develop-etch (EDE) method is utilized to fabricate rod-based photonic-crystal devices in III-V and SOI material systems. The thesis also presents an electrically-activated linear-waveguide photonic-crystal laser. A compact microcavity is created by introducing a defect inside a one-dimensional photonic crystal. Electrical-activation and edge-emission are achieved by patterning microcavity waveguides into p-i-n-doped epitaxial heterostructures. The compact photonic-crystal laser is anticipated to have impact on the integration of optical devices on the same chip.Solomon Assefa.Ph.D

Planeamento de redes de transporte de dados para o SKA (Square Kilometre Array)

Mestrado em Engenharia Eletrónica e TelecomunicaçõesThe SKA (Square Kilometre Array) will be the world’s largest and most sensitive radio telescope with a square kilometre (one million square metres) of collecting area, expecting to be able to clarify some of the main questions about the universe. This project is currently in the preparatory phase, having already established the regions and distributions of the various antennas and the location of signal processing and storage units. In order to satisfy the scientific requirements, the SKA is comprised of thousands of radio wave receivers (antennas) that need to be connected to a processing unit and data centre storage. Transmission distances and capacity depend on the configuration and type of antennas. This dissertation intends to submit a planning and optimization of transport networks between the antennas and the central processing units, in order to present an economic and spectral efficiency solution.O SKA (Square Kilometre Array) pretende ser o maior e mais sensível radiotelescópio do mundo com uma dimensão de um quilómetro quadrado (um milhão de metros quadrados) de área efetiva, esperando que seja capaz de esclarecer algumas das principais questões sobre o universo. Este projeto encontra-se atualmente na fase preparatória já tendo sido estabelecidas as regiões e as distribuições das várias antenas e a localização das unidades de processamento de sinal e armazenamento. Por forma a atender os requisitos científicos, o SKA é compreendido por milhares de recetores de ondas de rádio (antenas) que necessitam de ser interligados a uma unidade de processamento e armazenamento de dados central. As distâncias de transmissão e a sua capacidade dependem da configuração e do género de antenas. Esta dissertação pretende apresentar um planeamento e otimização de Redes de Transporte entre as antenas e as unidades de processamento central, por forma apresentar uma solução económica e com eficiência espectral