0000000000060518
AUTHOR
J. Ojeda-castaneda
showing 3 related works from this author
Non-Conventional Tunable Spatial Filtering
1987
A virtual display of the Fraunhofer diffraction pattern of any object is formed in the transverse source plane by theyirtual diffracted rays extqn0ing in the region to the left of the screen containing the transparencyl),2). Except for a few cases '')"°), the concept of virtual Fourier transform appears not to have been made use of. The main idea of this paper is, bearing in mind the property referred to in the above paragraph, to describe a novel spatial filtering technique. In this way, one can obtain different filtered images, by simply moving the point source along the optical axis. The basic theory is described below.
Geometrical Transformations In The Fraunhofer Plane
1987
A virtual display of the Fraunhofer diffraction pattern is generated solely by illuminating the object with a point source. If this pattern is imaged with an anamorphic system, several linear geometrical transformations can be achieved. Furthermore, a nonsymmetrical Fourier transformer with a variable degree of anamorphic magnification on the Fraunhofer pattern can be implemented.
Focal Length Measuring Technique Using The Talbot Effect
1987
The Talbot effect - or self-imaging phenomenon - is applied to the measurement of focal lengths. The technique only requires axial distances to be measured and is suitable for both converging and diverging thick lenses.