Mostrando ítems 1-10 de 135
Talbot and Lau phenomena implementation via a photorefractive converter
We propose a novel implementation of the Lau and Talbot effects. It employs a grating registered as modulation of birefringence in a Bi12SiO20 crystal. The systems proposed allow to control the visibility and in particular ...
DC term filtering techniques in digital holography
In numerical hologram reconstruction like in optical holography, there exist different diffraction orders, which many times produce difficulties for the image visualizations. In numerical reconstruction, the filtering of ...
Analysis of vibrations in a plate using interferometric methods
In this work some frequencies and modes of vibration of a thin plate were determined using interferometric methods like: real-time holographic interferometry, time-average holographic interferometry, digital speckle pattern ...
Speckle photography through different multiaperture pupils
(SPIE/ 18th Congress of the International Commission for Optics, 1999-07-19)
An image multiplexing method based on the internal modulation of speckle grains by employing different multiple aperture pupils for recording is proposed. The interferometric fringes profile and visibility in the Fourier ...
Double aperture speckle method using a BSO crystal for in plane displacement
The possibility of using a BSO crystal as a recording medium of specklegrams with carrying frequency fringes, to storage multiple interferograms, for uniform in-plane displacements, is presented. Experimental results are shown.
Speckle photography with different pupils in a multiple-exposure scheme
(Optical Society of America, 2000-01-01)
The use of different multiple-aperture pupils for recording each image in speckle photography is proposed -- The introduction of suitable spatial frequency carriers, by internally modulating imaged speckles, allows one to ...
Improvement of the signal-to-noise ratio in digital holography
(Sociedad Mexicana de Física, 2005-02)
A fundamental problem in optical and digital holography is the presence of speckle noise in the reconstruction process, which essentially diminishes the signal to noise ratio (SNR). For many applications, that reduction ...
Phase-difference images by digital holography applied to 3D surface contouring
(Academia Colombiana de Ciencias Exactas Físicas y Naturales, 2005-06)
The problem to determine the 3D-contour of objects with all sizes and shapes is a hot topic in diverse fields of optical research and engineering. Through the use of the numerical reconstruction of digital recorded holograms, ...
Logic operations by using modulated speckle
An alternative image multiplexing technique is proposed. In the arrangement implemented, the input is imaged by introducing a multiple aperture pupil in the imaging lens. Then, the speckle pattern is modulated by several ...
Obtención de estructuras de relieve en materiales de registro de haluros de plata
Diffraction transmission gratings were recorded in AGFA-8E75 film, chemically treated under processes with D-19 + potassium ferrocyanide and a chemical processing technique proposed for PE-2 film to obtain embossed stripes. ...