Short Optical Pulses
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. Facile Synthesis of Tellurium Nanowires and Study of Their Third-Order Nonlinear Optical Properties
We report on the synthesis of single-crystalline tellurium nanowires with different aspect-ratios prepared via facile surfactant-assisted synthesis under mild conditions. Short and long Te nanowires were synthesized by the reduction of tellurium dioxide by hypophosphorous acid with the assistance of polyoxyethylene (23) laurylether and cetyltrimethylammonium
J. Braz. Chem. Soc.. Publicado em: 2017-01
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2. Acopladores de cristais fotÃnicos e acesso mÃltiplo por divisÃo de cÃdigo Ãptico (OCDMA) com pulsos ultracurtos em fibras de Bragg / Photonic crystals couplers and optical code division multiple access (OCDMA) with optical ultra-short pulses in linear fiber Bragg gratings
This paper presents numerical simulation studies of propagation/switching of ultra-short pulses in photonic crystal couplers and Optical Code Division Multiple Access (OCDMA) using Fiber Bragg Grating (FBG). For coding were obtained analytically Gold codes. In the analysis of photonic crystal couplers (microstructured) investigated the properties of the prop
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/02/2012
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3. 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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4. Estudo da estabilidade do acoplamento de modos de um laser a fibra dopada com érbio com pulsos de femtossegundos e taxa de 10 GHz
In this work we show a study of mode-locking stabilization in an Erbium doped fiber laser with assynchronous mode-locking generating ultra-short pulses at the rate of 10 GHz. The fiber effects are presented as well as the mode-locking techniques. Also is presented a study of energy pulse stabilization, frequency and cavity, in addition an overview of stabili
Publicado em: 2009
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5. AmplificaÃÃo Raman de pulsos curtos em fibras Ãpticas com ganho periÃdico / Raman amplification of short pulses in optical fibers with periodic gain
Optical Amplifiers amplify incident light through stimulated emission, the same mechanism which is used by lasers. Indeed, an optical amplifier, it is not but a laser without feedback. Its main ingredient is optical gain which is realized when the amplifier is under pumping process (optically or electrically) in order to cause population inversion at electro
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/04/2008
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6. Estudo e aplicações do fenômeno de absorção de dois fótons em moléculas azo-aromáticas / Studies and applications of two-photon absorption in azo-aromatic molecules
Here we investigated fundamental and applied aspects of the two-photon absorption process in azoaromatic compounds. Azoaromatic molecules have been studied in the last few years due to their applications in optical storage devices, light modulators and surface relief gratings, processes related to the photo-isomerization mechanism. The main focus of the resu
Publicado em: 2007
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7. Amplificadores Ãpticos, estudos de polarizaÃÃo e geraÃÃo de pulso usando processos paramÃtricos em fibras Ãpticas
The recent telecommunication development can be, to a large extent, attributed to the capacity of transmitting information (video, sound and data) at high transmission rates (Tbits/s) through the optical fiber. The constant advances in the technological development of active and passive devices based on optical fibers have enabled a steady increase in commun
Publicado em: 2007
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8. Construction and evaluation of a laser induced breakdown spectroscopy instrument: application in alloy samples / Construção e avaliação de um instrumento para espectroscopia de emissão em plasma induzido por laser (LIBS) : aplicação em ligas metalicas
In this work a time resolved LIBS instrument (TRELIBS) was built and its performance evaluated in qualitative and quantitative analysis. Additionally, exploratory studies are presented on the influence of parameters that affect the LIBS analysis. The instrument was built employing optical systems and devices of modern technology: an ICCD device, an echelle p
Publicado em: 2007
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9. GERAÇÃO DE PULSOS ÓPTICOS CURTOS E MULTIPLEXAÇÃO NO DOMÍNIO DO TEMPO / GENERATION OF OPTICAL SHORT PULSES AND TIME DOMAIN MULTIPLEXING
This master thesis demonstrates the principle of the functioning of an optical time domain multiplex system using short pulses. Through the effect of mode locked to fiber ring laser, optical short pulses are generated at repetition of 2.48 GHz to the step that the scheduling is attributed to the use of optic passive devices which compose the experimental set
Publicado em: 2006
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10. Mistura de quatro ondas na propagaÃÃo de pulsos Ãpticos ultra-curtos em fibras com dispersÃo decrescente para sistemas WDM / Mixture of four waves in the propagation of ultra-short optical pulses in fiber wither dispersion decreasing for WDM systems
Serà estudado nesta dissertaÃÃo o comportamento da propagaÃÃo de trÃs tipos de pulsos Ãpticos (Solitons, Quasisolitons e Gaussianos) ultracurtos na regiÃo de 1.55μm e a eficiÃncia de conversÃo destes na geraÃÃo de pulsos por meio do fenÃmeno nÃo-linear de mistura de quatro ondas (FWM) em uma fibra comum e em fibras com dispersÃo decrescen
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/12/2005
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11. CHARACTERISATION OF ALLOPTICAL WAVELENGTH CONVERSION BY CROSS-GAIN MODULATION IN SEMICONDUCTOR OPTICAL AMPLIFIERS / CARACTERIZAÇÃO DA CONVERSÃO DE COMPRIMENTO DE ONDA POR MODULAÇÃO DE GANHO CRUZADO EM AMPLIFICADORES ÓPTICOS SEMICONDUTORES
Wavelength conversion of optical signals by all-optical techniques is an innovative and necessary technology for wavelength routed networks in the near future; the cross-gain modulation method is one of the simplest, in form, to attain this goal. Two categories of the main technique are presented: the classic, also known as pump and probe, and a novel one, n
Publicado em: 2005
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12. "Não linearidades ópticas em azocompostos" / Optical nonlinearities in azocompounds
This work reports on the temperature dependence of linear and nonlinear properties of azocompounds solutions due to isomerization mechanisms. The dependence of pipi* transitions on the linear structure of azocompounds is already noticeble in the measurements of absorption spectra as function of the temperature for the trans isomer. Knowing the energy levels
Publicado em: 2004