A simple interferometric method to measure the calibration factor and displacement amplification in piezoelectric flextensional actuators

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise teórica e experimental de um método interferométrico de detecção de fase óptica, auto-consistente e com elevada faixa dinâmica, aplicado à caracterização de atuadores piezoelétricos flextensionais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise teórica de uma nova técnica de processamento de sinais interferométricos baseada na modulação triangular da fase óptica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Método de detecção interferométrica de fase, com baixa profundidade de modulação, aplicado à medição de deslocamentos nanométricos em atuadores e mini-manipuladores piezoelétricos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Demodulação de sinais interferométricos de saída de sensor eletro-óptico de tensões elevadas utilizando processador digital de sinais

Pós-graduação em Engenharia Elétrica - FEIS

Sensor em fibra óptica aplicado à caracterização de atuadores piezoelétricos flextensionais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação da temperatura eletrônica da fase plasma e estudo da morfologia, estrutura molecular e crescimento do polímero proveniente de um plasma de benzeno excitado por tensão contínua

Pós-graduação em Física - FEG

Um estudo do efeito da composição dos vidros teluretos sobre os índices de refração linear e não linear

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Novas técnicas de detecção de fase óptica em interferômetros homódinos aplicadas à caracterização de atuadores piezoelétricos flextensionais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Geração de segundo harmônico em vidros teluritos TeO2 – LiNbO3

Pós-graduação em Ciência dos Materiais - FEIS

Efeito da incorporação de flúor nas propriedades de superfície de filmes DE aC:H

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Novas configurações de interferômetros de quadratura e de técnicas de detecção de fase óptica baseadas em phase unwrapping

Pós-graduação em Engenharia Elétrica - FEIS

Processo de esmerilhamento, polimento e caracterização de um Shear Plate

Shearplate is an optical glass plate having two flat surfaces and a small angle between them. The use of a high quality shear plate is essential to implement shear interferometric technique . The shear interferometry is a technique used to evaluate the light beam collimation. In order to guarantee the shearplate quality , the complete manufacturing process must be thoroughly monitored. In the manufacturing process, the first step consisted of the glass selection. The selected glass has been submitted to the process of cutting, gluing, chamfering, grinding and polishing. Each phase has been strictly monitored. The quality of the final result depends extremely on an appropriate starting condition, which arises from the grinding process, as the polishing process only recovers the brightness of the part, acting on a small scale on the wearing off of the part, as well as not changing the structured obtained in the grinding process. Respecting all stages of the manufacturing process, the quality of the part has evolved to a good result. The best result obtained showed PV distance of 162 nm, slightly less than λ / 4. This result is significant because the dimensions of the piece with respect to the dimensions of the polisher what interferes directly in the results. The closer are the dimensions of piece and the dimensions of the polisher, the greater the difficulty in controlling the propagation of errors

Medição interferométrica de fase óptica através do método de segmentação do sinal amostrado

Pós-graduação em Engenharia Elétrica - FEIS

New Improved Version of J 1 ...J 4 Interferometry Method and its Application to Nanometric Vibration Measurements

Piezoelectric ceramics, such as PZT, can generate subnanometric displacements, bu t in order to generate multi- micrometric displacements, they should be either driven by high electric voltages (hundreds of volts ), or operate at a mechanical resonant frequency (in narrow band), or have large dimensions (tens of centimeters). A piezoelectric flextensional actuator (PFA) is a device with small dimensions that can be driven by reduced voltages and can operate in the nano- and micro scales. Interferometric techniques are very adequate for the characterization of these devices, because there is no mechanical contact in the measurement process, and it has high sensitivity, bandwidth and dynamic range. A low cost open-loop homodyne Michelson interferometer is utilized in this work to experimentally detect the nanovi brations of PFAs, based on the spectral analysis of the interfero metric signal. By employing the well known J 1 ...J 4 phase demodulation method, a new and improved version is proposed, which presents the following characteristics: is direct, self-consistent, is immune to fading, and does not present phase ambiguity problems. The proposed method has resolution that is similar to the modified J 1 ...J 4 method (0.18 rad); however, differently from the former, its dynamic range is 20% larger, does not demand Bessel functions algebraic sign correction algorithms and there are no singularities when the static phase shift between the interferometer arms is equal to an integer multiple of  /2 rad. Electronic noise and random phase drifts due to ambient perturbations are taken into account in the analysis of the method. The PFA nanopositioner characterization was based on the analysis of linearity betw een the applied voltage and the resulting displacement, on the displacement frequency response and determination of main resonance frequencies.