Optical Coherent
Mostrando 1-12 de 43 artigos, teses e dissertações.
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1. Low-Overhead Low-Complexity Carrier Phase Recovery Technique for Coherent Multi-Band OFDM-Based Superchannel Systems Enabled by Optical Frequency Combs
Abstract In this paper, we have designed a low-overhead low-complexity carrier phase tracking scheme for OFDM-based superchannel transmission system enabled by optical frequency combs. In this scheme, taking advantage of the broadband phase coherence provided by optical frequency combs among the OFDM-bands, the carrier phase retrieved from pilot-subcarriers
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03
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2. A Multilayer Approach for Optical Network Planning
With the increase in demand to Backbone networks, one became fundamental the application of new telecommunication technologies for efficient use of devices and optical links, such as xPSK modulations with dual polarization, dispersion compensating fibers, coherent detection and digital processing signals. Thus, network planning using analytical models have b
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-03
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3. Nonlinear effects compensation in Optical Coherent PDM-QPSK Systems
Nonlinear effects has been appointed as the main limitation in coherent optical fiber transmission. Digital Back-Propagation algorithms and Maximum Likelihood Sequence Estimation are two of the current studied methods to cope with such impairment and extend the systems maximum reach. In this article, we analyzed both methods in a 112 Gb/s Dual Polarization Q
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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4. Spectrally-efficient 17.6-Tb/s DWDM optical transmission system over 678 km with pre-filtering analysis
We present and analyze a 17.6-Tb/s DWDM optical transmission composed of 79 channels with 224-Gb/s RZ-DP-16QAM modulation format per-channel and coherent detection. A maximum reach of 678 km is obtained with an optical recirculation loop composed by 226 km of pure-silica core fibers and EDFA amplification only in a 50-GHz grid system with spectral efficiency
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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5. Spectrally-efficient 17.6-Tb/s DWDM optical transmission system over 678 km with pre-filtering analysis
We present and analyze a 17.6-Tb/s DWDM optical transmission composed of 79 channels with 224-Gb/s RZ-DP-16QAM modulation format per-channel and coherent detection. A maximum reach of 678 km is obtained with an optical recirculation loop composed by 226 km of pure-silica core fibers and EDFA amplification only in a 50-GHz grid system with spectral efficiency
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-06
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6. Sistemas CDMA ópticos coerentes baseados em codificação de fase espectral / Coherent optical CDMA systems based on spectral phase coding
In this work we perform a comprehensive analysis of a spectral phase-encoded time spreading optical code division multiple access (SPECTS-OCDMA) system. Despite being a numerical study, efforts were concentrated on the investigation of more realistic scenarios using as much information as possible from implemented test-beds in laboratories. In this context,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/12/2012
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7. Estudos de sistemas OFDM para comunicações ópticas / Studies OFDM systems for optical communications
The development of digital modulation formats in optical communications systems is considered to be a promising way to increase the spectral efficiency and to combat the effects of signal degradation in optical fiber without changing the infrastructure already deployed. In this context, the technique called OFDM (orthogonal frequency division multiplexing) e
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/10/2012
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8. Influência da adição de nanopartículas de TiO2 na obtenção de compósitos a base de liga AA2014 fabricada via metalurgia do pó / Influence of the addition of TiO2 nanoparticles in the composites formation based AA2014 alloy manufactured by powder metallurgy
Aluminum matrix composites and its alloys, especially AA2014, are widely used in automotive and aeronautics applications. The properties of this are very influenced by hardening treatment, however its use is limited at temperatures above 150C due to loss of properties caused by the growth of precipitates at this temperature. The addition of a new phase, fine
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/06/2012
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9. Predição e identificação de danos internos em batatas por meio do biospeckle laser / Prediction and identification of potatoes in internal damagethrough the laser biospeckle
Food damages due to mechanical impacts at post harvest different phases are one of the biggest issues faced by food industry. In potatoes, productivity decrease due to impacts and physical damages can get to 40% during processing, storage, transportation and commercialization phases. Intern injuries, or bruising, are one of the biggest factors losses at pota
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/06/2011
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10. Estudo de viabilidade de integração de micro-lâmpadas incandescentes com filtros interferenciais. / Study of viability of integration of incandescent micro-lamps with interferometric filters.
In the present work was realized a study of the viability of integrating two optical devices: incandescent micro-lamps and interferometric filters with the intention of obtaining a single device with specific characteristics. The fabrication of these optical devices was made using dielectric materials, obtained by plasma-enhanced chemical vapor deposition (P
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/04/2011
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11. Analysis of signal processing techniques for optical 112 Gb/s DP-QPSK receivers with experimental data
This paper evaluates several signal processing techniques for optical dual-polarization quadrature phase-shift keying (DP-QPSK) coherent receivers, using offline post-processing of experimental data. In addition to electronically separating the two polarization multiplexed signals, the investigated signal processing algorithms also compensate for chromatic d
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2011-06
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12. Microlasers de cavidades estadio aplicados a detecção nanovolumetrica / Stadium cavities microlasers applied to the nanovolumetric detection
This work presents the development of resonant cavities based on chaotic billiard geometries built with semiconductor active optical medium for sensing applications. In spite of the classically chaotic behavior of the stadium, the quantum description of the problem in the semi-classical limit shows unexpected accumulations of the density of probability on cl
Publicado em: 2010