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Applicability of low macrobending loss hollow-core PCF to FTTH applications

Lona,D. G.; Hernández-Figueroa,H. E.; Cerqueira S. Jr.,Arismar; Stefanini,G.; Fragnito,H. L.
Fonte: Sociedade Brasileira de Microondas e Optoeletrônica e Sociedade Brasileira de Eletromagnetismo Publicador: Sociedade Brasileira de Microondas e Optoeletrônica e Sociedade Brasileira de Eletromagnetismo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 EN
Relevância na Pesquisa
36.06%
Fiber-To-The-Home (FTTH) technology has been significantly implemented in access networks, providing very high data rates transmission and a variety of digital content to subscribers. It involves an optical cable link being installed between the building entry point and each subscriber with the Multiple Dwelling Units (MDUs), i.e. flats and apartments. In other words, optical cable has to lie fairly straight to carry a strong signal, since typically is necessary to bend, twist and turn the lines in and out of tight corners without degrading the link connection. In this paper we propose the use of Hollow-Core Photonic Crystal Fiber (HC-PCF) for FTTH applications. It is presented an experimental analysis of the macrobending effects in a HC-PCF based on a comparison with traditional fibers and by following the ITU-T G.657B standard recommendations. We observe this fiber, with only 6.5 µm core, is bending loss insensitive, even at extremely small bending radius of 2 mm, in which it presents a loss of only 0.58 dB.

Low-Power Testing of Losses in Millimeter-Wave Transmission Lines for High-Power Applications

Han, S. T.; Comfoltey, E. N.; Shapiro, M. A.; Sirigiri, J. R.; Tax, D. S.; Temkin, R. J.; Woskov, P. P.; Rasmussen, D. A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/2008 EN
Relevância na Pesquisa
26.57%
We report the measurement of small losses in transmission line (TL) components intended for high-power millimeter-wave applications. Measurements were made using two different low-power techniques: a coherent technique using a vector network analyzer (VNA) and an incoherent technique using a radiometer. The measured loss in a 140 GHz 12.7 mm diameter TL system, consisting of 1.7 m of circular corrugated waveguide and three miter bends, is dominated by the miter bend loss. The measured loss was 0.3±0.1 dB per miter bend using a VNA; and 0.22±0.1 dB per miter bend using a radiometer. Good agreement between the two measurement techniques implies that both are useful for measuring small losses. To verify the methodology, the VNA technique was employed to measure the extremely small transmission loss in a 170 GHz ITER prototype TL system consisting of three lengths of 1 m, 63.5 mm diameter, circular corrugated waveguide and two miter bends. The measured loss of 0.05±0.02 dB per miter bend may be compared with the theoretical loss of 0.027 dB per miter bend. These results suggest that low-power testing of TL losses, utilizing a small, simple TL system and a VNA, is a reliable method for evaluating performance of low-loss millimeter-wave TL components intended for use in high-power applications.

A Temperature Sensor Based on a Polymer Optical Fiber Macro-Bend

Moraleda, Alberto Tapetado; García, Carmen Vázquez; Zaballa, Joseba Zubia; Arrue, Jon
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 26/09/2013 EN
Relevância na Pesquisa
36.27%
The design and development of a plastic optical fiber (POF) macrobend temperature sensor is presented. The sensor has a linear response versus temperature at a fixed bend radius, with a sensitivity of 1.92·10−3 (°C)−1. The sensor system used a dummy fiber-optic sensor for reference purposes having a resolution below 0.3 °C. A comprehensive experimental analysis was carried out to provide insight into the effect of different surrounding media on practical macro-bend POF sensor implementation. Experimental results are successfully compared with bend loss calculations.

Mode conversation losses in overmolded millimeter wave transmission lines

Tax, David S. (David Samuel)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 109 p.
ENG
Relevância na Pesquisa
26.66%
Millimeter wave transmission lines are integral components for many important applications like nuclear fusion and NMR spectroscopy. In low loss corrugated transmission lines propagating the HE,1 mode with a high waveguide radius to wavelength ratio (a/X), the transmission line loss is predominantly a result of mode conversion in components such as miter bends. The theory for determining losses in miter bends though is only approximate, and is based instead on the problem of the loss across a diameter-length gap between two waveguide sections. Through simulation, we verified that the existing analytic theory of this gap loss is correct; however, our simulations could not verify the assumption that the miter bend loss is half the loss in the gap. We also considered the problem of higher order modes (HOMs) mixed with an HE11 input entering the miter bend. Using a numerical technique, we found that the loss through the miter bend is dependent on both the amplitude of the HOM content as well as its phase relative to the phase of the HE11 mode. While the overall loss averaged across all phases remains the same with increasing HOM content, the power that fails to traverse the gap tends to increase, and it is this power that appears as very high order modes that will cause heating around the miter bend. For the ITER transmission line...

Transverse modes in large-mode-area fibers

Jiang, Zhuo (1978 - ); Marciante, John R. ; Bigelow, Nicholas P.
Fonte: University of Rochester Publicador: University of Rochester
Tipo: Tese de Doutorado Formato: Number of Pages:xiv, 111 leaves
ENG
Relevância na Pesquisa
26.44%
Thesis (Ph. D.)--University of Rochester. Dept. of Physics and Astronomy, 2010.; This thesis is devoted to the study of transverse modes in large-mode-area (LMA) fibers. It highlights the importance of transverse spatial-hole burning (TSHB) effect in LMA multimode fibers through experiments and simulations. The measured beam-quality factor decreases until the gain becomes saturated in an amplified spontaneous emission (ASE) source based on an Yb-doped LMA multimode fiber. At saturation, the beam-quality factor reaches a minimum, beyond which it increases again. Numerical simulation trends based on a model using spatially resolved gain and transverse-mode decomposition of the optical field agree with the experimental results. A simplified model without TSHB is shown not fit to predict the observed behavior of beam quality in LMA fibers, especially at high powers. A comparison of both models shows that TSHB is also critical for properly modeling beam quality in LMA fiber amplifiers. New precise modal decomposition methods for field distribution with phase information and intensity distribution without phase information respectively, are presented and extended to single-mode fiber characterization. In these new methods, different mode sets are calculated using varied sets of fiber parameters...

Desenvolvimento de metodologias de avaliação e monitoramento do desgaste no par tribológico RISER/ENRIJECEDOR; Development of monitoring and evaluation methodologies of wear on tribological pair riser/bend stiffener

Moraes, Monique Alves Franco de
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
Relevância na Pesquisa
26.48%
Neste trabalho foram desenvolvidas e aplicadas duas metodologias para quantificar o desgaste em amostras de risers e enrijecedores utilizando uma máquina de medir a três coordenadas (MM3C). Tais amostras foram testadas em um tribômetro capaz de realizar ensaios de desgaste por deslizamento em escala real. Adicionalmente, foram correlacionados os eventos que ocorrem durante o processo de desgaste destas amostras com as vibrações na estrutura do tribômetro. A primeira metodologia foi aplicada na estimativa do desgaste linear em amostras de risers, com base na variação de espessura, enquanto que a segunda foi destinada à estimativa do desgaste volumétrico em amostras de enrijecedores, tendo por base a perda de volume das mesmas. Para avaliar a perda de espessura nas amostras de riser foi utilizado o software Calypso® na definição do alinhamento e na determinação e execução da estratégia de medição. Já na avaliação do volume das amostras de enrijecedores, foi utilizado o mesmo software na definição do alinhamento. O software Dimension Volume® foi empregado na definição e execução da estratégia de medição, e, para calcular o volume destas amostras, foi elaborado e utilizado um programa em Matlab®. Com o intuito de analisar as vibrações durante o ensaio de desgaste...

Understanding bending losses in holey optical fibers

Baggett, J.; Monro, T.; Furusawa, K.; Richardson, D.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2003 EN
Relevância na Pesquisa
46.69%
Extremely large mode area fibers that are single-moded over a broad wavelength range can be created using holey fiber technology. However, as with any fiber, the largest mode areas that are practically feasible are ultimately determined by bending losses. It is therefore essential to gain an understanding of the factors that influence bend loss in these fibers in order to form accurate predictions that can facilitate improved bend loss design. Here, we present the first detailed study of transition loss and pure bend loss in a holey fiber, and consider the impact of the fiber structure. A theoretical model is derived that retains the full refractive index profile of a holey fiber. This approach is used to predict the bend loss in large mode area holey fibers and is validated through comparison with experimental data. For the fibers under study here, we demonstrate that pure bend loss is the dominant component of macro-bend loss and that the hole configuration within the cladding can strongly influence this loss.; http://www.elsevier.com/wps/find/journaldescription.cws_home/505711/description#description; Joanne C. Baggett, Tanya M. Monro, Kentaro Furusawa, Vittoria Finazzi and D. J. Richardson

Fiber optic sensors and self-reference techniques for temperature measurements in different industrial sectors

Tapetado Moraleda, Alberto
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
36.03%
El objetivo de este trabajo se centra especialmente en el desarrollo de sensores de fibra óptica y técnicas de autoreferencia para la medida de la temperatura en diferentes entornos industriales. El primer objetivo de este trabajo consiste en el diseño y desarrollo de un sensor de fibra óptica de bajo coste para la medida de la temperatura en transformadores de potencia y aplicaciones biomédicas. En estas aplicaciones, el uso de sensores de temperatura tradicionales resulta inadecuado debido a la presencia de fuertes interferencias electromagnéticas que pueden perturbar la lectura de la temperatura. Uno de los requisitos fundamentales para diseñar un sensor de temperatura que pueda usarse en aplicaciones biomédicas es el uso de materiales biocompatibles en su fabricación. En este sentido, una configuración simple que permite cumplir con los requisitos mencionados anteriormente es la modulación por intensidad en fibras poliméricas. Este tipo de sensores basan la lectura de la temperatura en medir las variaciones de potencia óptica en función de los cambios de temperatura que se aplican sobre el sensor. En este contexto, el uso de la tecnología asociada con la fibra óptica de plástico ofrece ventajas competitivas frente a otros materiales...

Effects of the coating in single-mode slab waveguide with varying curvature:a new approach to understanding bend loss

Durniak, Celine; Love, John
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
56.31%
We present analytical and numerical results that describe and quantify bend loss. Our approach is based on the coupling between fundamental and cladding modes with changing curvature in single-mode waveguides with finite cladding and absorbing coating.

Bend Loss in Silica Optical Fibre with Low Refractive Index Coating

Bulla, Douglas; Love, John
Fonte: Conference Organising Committee Publicador: Conference Organising Committee
Tipo: Conference paper
Relevância na Pesquisa
56.38%
Silica optical fibre, coated with low refractive index material, was characterized against bend losses. The fibre showed low bend loss compared with similar fibre coated with standard refractive index material, and with a standard SMF.

Suppression of Cladding-mode Coupling in Single-mode Slab Waveguides of Varying Curvature

Durniak, Celine; Love, John
Fonte: Conference Organising Committee Publicador: Conference Organising Committee
Tipo: Conference paper
Relevância na Pesquisa
36.09%
Bend loss can be quantified by following coupling between fundamental and cladding modes with changing curvature on a finite cladding, single-mode slab waveguide. A delineation criterion provides a boundary between approximately adiabatic and non-adiabati

Resonant Bend Loss in Leakage Channel Fibers

Barankov, R. A.; Wei, K.; Samson, B.; Ramachandran, S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/05/2012
Relevância na Pesquisa
36.25%
Leakage channel fibers, designed to suppress higher-order modes, demonstrate resonant power loss at certain critical radii of curvature. Outside the resonance, the power recovers to the levels offset by the usual mechanism of bend-induced loss. Using C$^2$-imaging, we experimentally characterize this anomaly and identify the corresponding physical mechanism as the radiative decay of the fundamental mode mediated by the resonant coupling to a cladding mode.; Comment: 3 pages, 4 figures, submitted to Optics Letters

Predicting macrobending loss for large-mode area photonic crystal fibers

Nielsen, M. D.; Mortensen, N. A.; Albertsen, M.; Folkenberg, J. R.; Bjarklev, A.; Bonacinni, D.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/04/2004
Relevância na Pesquisa
36.37%
We report on an easy-to-evaluate expression for the prediction of the bend-loss for a large mode area photonic crystal fiber (PCF) with a triangular air-hole lattice. The expression is based on a recently proposed formulation of the V-parameter for a PCF and contains no free parameters. The validity of the expression is verified experimentally for varying fiber parameters as well as bend radius. The typical deviation between the position of the measured and the predicted bend loss edge is within measurement uncertainty.; Comment: Accepted for Optics Express

Effect of Bend Loss on Parabolic Pulse Formation by Active Dispersion Tailored Fibers

Ghosh, Dipankar; Basu, Mousumi
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 18/12/2009
Relevância na Pesquisa
46.44%
This work reports the performances of straight and bent active normal dispersion decreasing fibers (NDDF), with spatial nonlinear variation, to form parabolic self-similar pulses. The core radius changes along the NDDF length, thereby altering the transverse field distribution lengthwise. Hence bend loss is no longer a constant quantity. Including this loss variation, we investigate the performances of NDDFs as generators of parabolic self-similar pulses. In view of the small changes of relative refractive index differences during production, we obtain several NDDFs with variations of core radii. Suitable choice of index differences and bend radius of curvature of the fibers leads to obtain similaritons. Even for sufficiently small index differences and bend radii, parabolic pulses are formed at the cost of higher optimum length in comparison to straight fibers. The comparative study on the straight and bent NDDFs with different index difference values is helpful for fiber optic manufacturers to fabricate the proposed NDDFs.; Comment: 3 pages, 7 figures

Low bend loss waveguides enable compact, efficient 3D photonic chips

Arriola, Alexander; Gross, Simon; Jovanovic, Nemanja; Charles, Ned; Tuthill, Peter G.; Olaizola, Santiago M.; Fuerbach, Alexander; Withford, Michael J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/02/2013
Relevância na Pesquisa
46.31%
We present a novel method to fabricate low bend loss femtosecond-laser written waveguides that exploits the differential thermal stabilities of laser induced refractive index modifications. The technique consists of a two-step process; the first involves fabricating large multimode waveguides, while the second step consists of a thermal post-annealing process, which erases the outer ring of the refractive index profile, enabling single mode operation in the C-band. By using this procedure we report waveguides with sharp bends (down to 16.6 mm radius) and high (80%) normalized throughputs. This procedure was used to fabricate an efficient 3D, photonic device known as a pupil-remapper with negligible bend losses for the first time. The process will also allow for complex chips, based on 10's - 100's of waveguides to be realized in a compact foot print with short fabrication times.; Comment: 9 pages, 6 figures

Design of a Low Loss Metallo-Dielectric EBG Waveguide at Submillimeter Wavelengths

Llombart, Nuria; Mazzinghi, Agnese; Siegel, Peter H.; Freni, Angelo
Fonte: IEEE Publicador: IEEE
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em /07/2009
Relevância na Pesquisa
36.03%
In this letter we show the viability of using concentric cylindrically-periodic (CP) dielectrics to realize low-loss propagation at submillimeter wavelengths. Most of the power in the CP Waveguide (WG) is confined to an air core propagating a TE_(01) mode. The TM_(11) mode degeneracy is removed over a very wide bandwidth by a series of periodically spaced dielectric rings that are optimized in thickness and spacing. The new waveguide differs from classical Bragg fibers in that we use only a small number of dielectric layers (2-4), and terminate the outer layer with an external metal coating. We include several designs and describe the optimization procedure that was used to realize structures with low propagation and bend loss.

Effect of Additional Layers on Bend Loss in Buried Channel Waveguides

Tomljenovic-Hanic, Snjezana; Love, John; Ankiewicz, Adrian
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
66.37%
The authors propose a new strategy to increase or decrease bend loss in single-mode buried channel waveguides in a predictable manner. This strategy is based on the presence in the cladding of additional layers with different refractive indices on either

New Design for a Variable Optical Attenuator Based on a Bent Channel Waveguide

Tomljenovic-Hanic, Snjezana; Krolikowski, Wieslaw
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
46.19%
We present a new method for bend loss control in a curved channel optical waveguide and employ it in a novel design of a thermo-optic variable optical attenuator. We show that the introduced asymmetric refractive index profile of the wave-guide structure, combined with the optimal placement of the heating electrodes, leads to a significant increase of the dynamic range of the attenuator.

Low-Loss Singlemode Waveguide and Fibre Bends

Tomljenovic-Hanic, Snjezana; Love, John; Ankiewicz, Adrian
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
35.97%
A new theoretical strategy for reducing bend loss is presented. It is based on the concept of introducing both depressed and increased index regions into the cladding of planar waveguides on the outside of the bent core. A similar strategy can be applied

Analysis of Bend Loss in Waveguides Employing Photonic Band Gap Effect

Tomljenovic-Hanic, Snjezana; Ankiewicz, Adrian
Fonte: Kluwer Academic Publishers Publicador: Kluwer Academic Publishers
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
66.55%
We analyse bend loss properties of a band gap-guided periodic structure, and give reasons for the effects found. In many cases, a tight bend produces only a slight reduction in power transmitted. We also make a comparison of bend losses in conventional waveguides and bendresistant waveguides.