Optical Filters
Mostrando 1-12 de 50 artigos, teses e dissertações.
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1. CONSTRUCTION OF A LOW-COST POLARIMETER FOR EDUCATIONAL PURPOSES
This paper describes the construction of a polarimeter for the identification of chemical substances. The device was built with low-cost materials, measures the phenomenon of optical activity and has educational applicability. The measurement of optical activity is achieved through the measurement of the resulting polarized radiation in a photodiode connecte
Quím. Nova. Publicado em: 2021-03
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2. Color electron microprobe cathodoluminescence of Bishunpur meteorite compared with the traditional optical microscopy method
Abstract Cathodoluminescence (CL) imaging is an outstanding method for sub classification of Unequilibrated Ordinary Chondrites (UOC) - petrological type 3. CL can be obtained by several electron beam apparatuses. The traditional method uses an electron gun coupled to an optical microscope (OM). Although many scanning electron microscopes (SEM) and electron
REM, Int. Eng. J.. Publicado em: 2018-04
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3. Optical cryptography through analog control of amplitude and delay of spectral slices: anlysis for NRZ and DQPSK signals. / Criptografia Ãptica mediante controle analÃgico da amplitude e do atraso de fatias espectrais: anÃlise para sinais NRZ e DQPSK.
This work investigates a technique to encrypt the optical signal for Transparent Optical Network, TON, in order to safeguard the confidentiality and guarantee the security of informations that are transmitted through the Telecommunications Network. The technique is assessed on the physical layer of the reference model for open systems interconnection, OSI, a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/11/2012
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4. PROTETORES SOLARES À BASE DE FILTROS INORGÂNICOS: DESENVOLVIMENTO E CARACTERIZAÇÃO
The inorganic sunscreens represented mainly by titanium dioxide (TiO2) and Zinc Oxide (ZnO), were classified as inert particles, therefore, they are pointed out as the best way to protect the skin against the harmful effects of ultraviolet radiation (UV). However, recent studies suggest that these particles have several stability problems that may lead to a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/01/2012
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5. 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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6. Transmission of a 20 Gb/s NRZ OOK signal throughout a 390 km fiber link and a cascade of 11 x 50 GHz filters and 9 x EDFAs
This paper presents a qualitative analysis of the impact caused by fiber propagation effects and by a cascade of optical filters, designed for 10 Gb/s NRZ OOK transmission, and optical amplifiers on a 20 Gb/s NRZ OOK optical signal traveling a 390 km fiber link. The choice for such bit rate and modulation format has been driven by the 50 GHz bandwidth of the
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2011-06
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7. Sistema de monitoramento óptico banda larga direto para fabricação de filmes finos multicamadas com sincronização sensorless / Broadband direct optical monitoring system for multilayer thin film manufacturing with sensorless synchronization
Para a fabricação de filtros ópticos com característica espectral crítica, utiliza-se a tecnologia de filmes finos multicamadas, a qual exige o monitoramento e controle de espessura dos filmes com alta precisão. O sistema tradicional de monitoramento de espessura de filmes, baseado em cristal ressonante, não atende aos requisitos de precisão e repeti
Publicado em: 2011
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8. Filtro de interferência variável e descrição de uma aplicação: dispositivo multicanal espectral para análise ambiental. / Variable interference filter and description of an application: multichannel spectral device for environmental analysis.
O presente trabalho apresenta o desenvolvimento de um método de obtenção e a caracterização de filtros ópticos de interferência de banda passante variável que, constituídos por refletores dielétricos multicamadas de filmes finos intercalados por cavidades de Fabry- Perot não planares com espessuras linearmente variáveis, apresentam a propriedade
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/02/2010
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9. Flexible tunable spectrum sliced microwave photonic filter using parallel Fabry-Pérot filters and Fiber Bragg Grating
A simple and low-cost spectrum sliced microwave photonic filter with high tunability has been implemented. This is based on use of two Fabry-Pérot filters with same free spectral range connected in parallel but one filter with an external fiber delay. An extension of this configuration with Fiber Bragg Grating (FBG) as delay element is also demonstrated. Th
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2010-12
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10. UV dominant optical emission newly detected from radioisotopes and XRF sources
The current paper reports first and definite experimental evidence for γ-, X-, or β radiation causing UV dominant optical radiation from (1) radiochemicals such as 131I; (2) XRF sources such as Rb XRF source present as salts; and (3) metal sources such as 57Co, and Cu XRF sources. Due to low quantum yield a need arose to develop two techniques with narrow
Brazilian Journal of Physics. Publicado em: 2010-03
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11. Projeto de filtros tipo "só-pólo" para malhas de sincronismo de fase de alta frequência. / Design of all-pole filters for high frequency phase locked loops.
The evolution of communication systems is discussed, with emphasis on optical technology. Special consideration is given to the continuous need for increasing the capacity of such systems, and the impact over future optical communication. In view of the great demands imposed over the capacity of future optical systems, an overview is presented of two recent
Publicado em: 2010
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12. Development of an optical fluorescence imaging system for medical use / Desenvolvimento de um sistema por imagem de fluorescência óptica para uso médico-odontológico
Optical fluorescence has been applied to several medical areas, as to monitor drug degradation and cancer detection, due to its high sensitivity, simplicity and fast response. Non-invasive and non-destructive assessment of tissues using this technique is very attractive for clinical diagnosis. Hence, the aim of was the development of an optical fluorescence
Publicado em: 2010