Beam Optics
Mostrando 1-12 de 19 artigos, teses e dissertações.
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1. Generation of Non-diffraction Vortex Beam and Its Application in Digital Communication
Abstract An axicon-frustum basin-type Bessel resonator is designed for generating non-diffraction vortex beams with opposite propagation directions under different conditions. Based on the theory of geometric optics, the principle of creating vortex beams is analyzed in this axicon-frustum basin-shaped resonant cavity. It is shown that a non-diffraction vort
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 19/06/2019
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2. Effect of laser phototherapy in the prevention and treatment of chemo-induced mucositis in hamsters
The aim of this study was to investigate the effect of laser phototherapy (LPT) in the prevention and/or treatment of oral mucositis induced by 5-fluorouracil (5-FU; Eurofarma, São Paulo, Brazil) in hamsters. Ninety-six hamsters were divided into four groups (n = 24): Control (no treatment); Preventive [LPT from day (D) D-5 to D+5]; Therapeutic (LPT from D+
Braz. oral res.. Publicado em: 11/06/2013
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3. Sintonia dos parâmetros de operação do primeiro estágio de aceleração do Mícroton do IFUSP / Tuning the Operational Parameters of the First Microtron Stage
O Laboratório do Acelerador Linear (LAL) do Instituto de Física da Universidade de São Paulo está construindo um acelerador de elétrons do tipo Mícrotron. O acelerador possui dois estágios de aceleração: o Mícrotron booster e o Mícrotron Principal. Atualmente, o sistema injetor do acelerador, que é um acelerador linear, dispõe de um feixe de el�
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/03/2012
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4. Estudo da decomposição fotoquímica por exposição à luz UV de fotorresinas positivas
Positive photoresists are widely used in lithographic process in microelectronics and in optics for the fabrication of relief components. With the aim of identifying molecular modifications among positive photoresists unexposed and previously exposed to ultraviolet light the electron stimulated ion desorption technique coupled to time-of-flight mass spectrom
Química Nova. Publicado em: 2012
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5. Desenvolvimento de processo litográfico tri-dimensional para aplicação em microóptica integrada. / Development of three-dimensional lithographic process for application in integrated micro-optics.
O presente trabalho tem como objetivo desenvolver um processo de fabricação de elementos micro-ópticos utilizando-se litografia por feixe de elétrons, empregando o resiste SU-8, negativo e amplificado quimicamente, sobre substrato de Si. Para tanto, é realizado o estudo dos parâmetros do efeito de proximidade a, b e h para se modelar e controlar os efe
Publicado em: 2010
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6. Propagação não linear de pulsos em estruturas 1D com band gap fotonico / Nonlinear pulse propagation in one-dimensional photonic band gap structures
The interaction of ultrashort optical pulses with photonic band gap materials has been studied by considering light propagation through one-dimensional photonic band gap structures, composed of a periodic multilayer stack of dielectric materials whose unitary cell consists of a pair of layers with different refractive indices n1and n2, respectively. One of t
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/08/2009
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7. Simulation of the plasma meniscus with and without space charge using triode extraction system
In this work, simulation of the singly charged argon ion trajectories for a variable plasma meniscus is studied with and without space charge for the triode extraction system by using SIMION 3D (Simulation of Ion Optics in Three Dimensions) version 7 personal computer program. The influence of acceleration voltage applied to the acceleration electrode of the
Brazilian Journal of Physics. Publicado em: 2009-03
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8. Construção de uma armadilha magneto-ótica para aplicações em informação quântica e física atômica / Construction of a Magnet-Optical Trap for Aplications at Quantum Information and Atomic Physics
We built a magneto-optical trap (MOT) for rubidium as a first step for the trapping of a cloud of cold atoms in a periodic potential formed by light beams. This system will be used for experiments in atom physics, with possible applications in quantum information. A MOT is necessary to avoid the problems imposed by the thermal agitation of the atoms to the m
Publicado em: 2009
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9. Multicolor Quantum Correlations in the Optical Parametric Oscillator / Correlações quânticas multicolores no oscilador paramétrico ótico
We have investigated the collective quantum properties of the three bright light beams produced by an optical parametric oscillator (OPO) operating above threshold, named pump, signal, and idler. We have analyzed experimentally their intensity and phase quantum fluctuations, and how they are correlated. For the first time, we have observed the existence of p
Publicado em: 2008
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10. Acoplamento de dois feixes com lasers de femtossegundos em vapor de Rb
Femtosecond lasers operating in the mode-locked regime have a repetition rate determined by the round trip time of the pulse inside the laser cavity (TR = 2L/c). For Ti:sapphire lasers the repetition rate is typically of the order of 100 MHz, with TR 10 ns. Under this condition TR may be smaller then the population relaxation time (T1) and the coher
Publicado em: 2007
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11. Fabricação e caracterização de Guia de Onda Polimerica a base de PMMA modificado por plasma de CHF3 / Polymeric optical waveguides fabricated by plasma fluorination process
Polymeric optical devices have been studied in communication and interconnection optics due to the intrinsic versatility of polymers molecular structure, that allows advantageous refractive index modeling for core and cladding, and also to their easy fabrication process or patterning capability. PMMA, polymethylmetacrylate, shows the best optical properties
Publicado em: 2007
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12. Commissioning of the injector system of the IFUSP Microtron / "Início de operação e caracterização do sistema injetor do Mícrotron do IFUSP"
In this work we present the commissioning of the IFUSP Microtron injector system. We developed a new method to treat misalignments on a single lens as well as in a group of them. We installed an image acquisition system to acquire beam images from the fluorescent screen monitor. Emittance was measured and found to be (2,32 ± 0,05) pi.mm.mrad, independently
Publicado em: 2006