High Harmonic Generation
Mostrando 1-12 de 13 artigos, teses e dissertações.
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1. Geração de harmônicos de pulsos laser de femtossegundo pela técnica de conversão de frequência em capilares preenchidos com gases nobres / Harmonics generation of femtosecond laser pulses by the technique of frequency conversion in noble gas filled capillaries
O propósito principal desta tese foi a implementação e estudo da geração de pulsos laser de femtossegundos em comprimentos de onda curtos (ultravioleta profundo, ultravioleta de vácuo e ultravioleta extremo) pela técnica de conversão de frequência em capilar preenchido com gás nobre. Esta técnica de conversão de frequência tem feito diversas con
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/06/2012
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2. Estudo das transiÃÃes de fase do RbBi0,31 3Nd0,02 W8/3O9, submetido a variaÃÃes de pressÃo hidrostÃtica e temperatura. / Studies of phase transitions of RbBi0,313Nd0,02W8/3O9 submit variation of hydrostatic pressure en temperature
Tungsten bronzes has attracted great attention owing to it is interesting physical properties. Hexagonal tungsten of the form AxWO3 (with A = K, Rb, Cs), are well know superconductors. The RbBi1/3W8/3O9 (RBW) material, belongs to the valence balanced hexagonal tungsten materials with ABxW3-xO9 stoichiometry (with A = Cs, K, Rb, Tl, and B = Bi, Nd, Ta, Zr, Sc
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/02/2009
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3. Desenvolvimento de um laser de Nd:YLF bombeado por diodo laser e duplicado em frequencia para 657 nm / Development of a diode pumped Nd:YLF laser, frency doubled to 657 nm
Atomic clocks are used today in a number of scientific and technological applications, ranging from tests of relativity, or variations of fundamental constants, to the use in navigation and telecommunication. The next generation of such high precision devices will be based on optical transitions of suitable laser cooled and trapped atoms. In this work we des
Publicado em: 2009
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4. Raman spectroscopy in kdp crystals and nanotubos of carbon (Implantation of the Technique) / Espectroscopia Raman em cristais de kdp e nanotubos de carbono (Implantação da Técnica)
Currently, physicist have developed new techniques for characterization materials, mainly in the field of new materials that are being produced from existing materials such as glass, ceramics, polymers, semiconductor and superconductor materials, magnetic materials, etc. In that line, the Group of Physic of materials of Amazon has acquired new techniques for
Publicado em: 2008
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5. Projeto de um retificador trifásico regenerativo com elevado fator de potência e controle em coordenadas dq0 implementado no DSP TMS320F2812
This work presents the design of a regenerative three-phase switching rectifier with high power factor and control in dq0 coordinates implemented on DSP TMS320F2812 of Texas InstrumentsTM. The controls have used the Clark and Park transformations and the bilinear equation of Tustin, so that the design of the digitals controllers, carried through on the frequ
Publicado em: 2006
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6. GLASS ELECTROTHERMAL POLING AND CHARACTERIZATION TECHNIQUES / POLARIZAÇÃO ELETROTÉRMICA DE VIDROS E TÉCNICAS DE CARACTERIZAÇÃO
It is possible to create a second order non linearity in silica samples with the poling process. The glass samples with an induced X(2) have a potential application on the fabrication of optical devices such as modulators and frequency converters. In the electrothermal poling process, high voltage and high temperature are applied to the samples forming an io
Publicado em: 2004
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7. Espectroscopia Ãptica nÃo linear em sistemas atÃmicos envolvendo nÃveis de Rydberg
In this thesis we study nonlinear optical effects in alkali vapors, in which Rydberg levels play the role of near resonant intermediate levels, focusing our attention in processes such as: four wave mixing (FWM), two photon absorption, sum frequency generation (SF) and difference frequency generation (DF). We analyze a FWM process with two-photon transitions
Publicado em: 2002
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8. ULTRA-SHORT OPTICAL PULSES GENERATION USING RATIONAL MODE-LOCKING IN FIBER LASERS / GERAÇÃO DE PULSOS ÓPTICOS ULTRACURTOS USANDO A TÉCNICA DE MODE-LOCKING RACIONAL EM LASERS A FIBRA
This work describes a simple and stable harmonically mode- locked erbium-doped fiber ring laser, that produces high power, ~ 1 ps transform-limited sech optical pulses. Pulse trains with different high repetition rates were obtained using harmonic mode-locking and rational harmonic mode- locking techniques. The temporal and spectral characteristics of the pu
Publicado em: 2000
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9. Invited Review Article: Imaging techniques for harmonic and multiphoton absorption fluorescence microscopy
We review the current state of multiphoton microscopy. In particular, the requirements and limitations associated with high-speed multiphoton imaging are considered. A description of the different scanning technologies such as line scan, multifoci approaches, multidepth microscopy, and novel detection techniques is given. The main nonlinear optical contrast
American Institute of Physics.
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10. Nonlinear optical measurement of membrane potential around single molecules at selected cellular sites
Membrane potential around single molecules has been measured by using the nonlinear optical phenomenon of second harmonic generation. This advance results from the interaction between a highly dipolar molecule with a selectively directed highly polarizable 1-nm gold particle. With this approach, a second harmonic signal, which is enhanced by the nanoparticle
The National Academy of Sciences.
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11. Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence
Multiphoton microscopy relies on nonlinear light–matter interactions to provide contrast and optical sectioning capability for high-resolution imaging. Most multiphoton microscopy studies in biological systems have relied on two-photon excited fluorescence (TPEF) to produce images. With increasing applications of multiphoton microscopy to thick-tissue “i
National Academy of Sciences.
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12. The role of London forces in defining noncentrosymmetric order of high dipole moment–high hyperpolarizability chromophores in electrically poled polymeric thin films
Graphs of second harmonic generation coefficients and electro-optic coefficients (measured by ellipsometry, attenuated total reflection, and two-slit interference modulation) as a function of chromophore number density (chromophore loading) are experimentally observed to exhibit maxima for polymers containing chromophores characterized by large dipole moment
The National Academy of Sciences of the USA.