RESUMO
A method for determining the position of the zero-order fringe in a metrological experiment with digital speckle pattern interferometry is proposed. It is based on an averaging procedure with shifted images obtained before and after a load is applied. This technique is a complement to the phase-shifting methods. Experimental examples are shown.
RESUMO
We implement optical logic operations, using a polarization-encoding architecture based on digital speckle pattern interferometry (DSPI). The method is based on the intensity dependence of DSPI on the rotation of the polarization direction in the paths of the interferometer between acquisition of frames. The 16 two-input logic operations can be achieved and stored in a host computer. This scheme also offers the possibility of creating dynamic logic gates.
RESUMO
A method for digital holographic contouring that uses a diffraction grating to generate the reference beam and to introduce adequate phase delay in the object beam is described.
RESUMO
A new arrangment for an electronic speckle pattern interferometer is reported in which an off-axis reference beam is used, thereby eliminating alignment problems.
RESUMO
A simple electronic speckle-shearing-pattern interferometer, in which the image of an object is focused and sheared with a split lens onto a diffuser, is described. The sheared images on the diffuser are focused by a television camera and then digitized and processed in a host computer. The results obtained for two basic types of shearing, lateral and radial, are presented.
RESUMO
A general expression for the problem of on-axis light distribution in converging spherical waves, diffracted at a circular aperture, is obtained. The solution is valid for small as well as for high Fresnel numbers (N) and also includes a tilt in the aperture. The influence of the tilt on the focal shift related to small values of N, and the symmetry of the field with respect to the geometrical focal plane, are analyzed.
