Sistema embarcado para operação e alinhamento de sensor de frentes de onda do tipo quadricélula

• Ano de defesa: 2011
• Autor(a) principal: Thiago de Oliveira Coura
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Sensor de frentes de onda; Aberração óptica; Quadricélula; Hartmann-Shack; Sistema embarcado; Óptica adaptativa; Sensor de posição; Polinômios de Zernike; Sistema microcontrolado; Engenharia elétrica
• Link de acesso: http://hdl.handle.net/1843/BUOS-8TAMZJ

This work deals with the development of a system for data acquisition and transmission; and the operation of a Hartmann wavefront sensor, using a position-sensitive device of the quad-cell type, with a low cost microcontrolled system. Adaptive optics involves techniques for real-time detection and correction of phase distortions in light beams. These aberrations can be proportional to modifications of the refraction index along the optical path due to atmospheric turbulence or imperfections in the refractive or reflective optical components. Applications involve CD/DVD readers and writers, astronomic observation through turbulent atmosphere, laser-based ophthalmic surgeries or in industrial applications in inspection of precision components. Wavefront sensorsthat use the Hartmann(-Shack) method employ conventional cameras and need successive and time consuming processing steps for the determination of phase aberration. However, wavefront sensors of the quad-cell type represent an improvement over conventionalcameras rendering the computational effort less intense, therefore leading to higher operational frequencies. A distinction of this work, considering the advantages of quad-cells, lies in the reconstruction of wavefronts for the first five Zernike terms targeting the alignment of the Hartmann mask under five degrees of freedom. This is possible by means of an optimized algorithmic approach to reconstruct the wavefrontthat allows the entire process to be performed in the system itself.