Amparo Pons Martí

Photoelastic Analysis of Partially Occluded Objects With an Integral-Imaging Polariscope

Polariscopes are the basic instruments used for the analysis of the stress state of transparent materials. Polarized light passing through a 3D object carries the integrated effect of the stress field along the light path. Therefore, conventional polariscopes are not able to discern the stress state of objects involving multiple plates with mutual occlusions. In this paper we propose a novel experimental system for three-dimensional stress analysis based on the combination of a polariscope and Synthetic Aperture Integral Imaging technique. Experimental results show the systems ability to recover the information of the stress distribution of a set of plates located at different depths having mutual occlusions.

Effective axial superresolution in single-photon 4Pi microscopy by Toraldo rings

We demonstrate theoretically the feasibility of single-photon 4Pi-confocal microscopy. By inserting a pair of properly designed multi-ring phase-only pupil filters in the illumination path of a 4Pi microscope the height of the sidelobes of the point spread function is importantly reduced, so that there is not ambiguity in the 3D image. Then, an axial resolution up to four times higher than that of single-photon confocal microscope can be effectively achieved.

Analysis of lens aberrations using a retinoscope as a Foucault test

It is presented a quite simple procedure for measuring the astigmatism aberration of lenses by using an optometric and ophthalmic instrument, the retinoscope, as a focimeter.

Inverse focal shift in truncated cylindrical waves

We report on a general analytical procedure to analyze the axial focusing properties of uniform cylindrical waves truncated by a rectangular window. The resulting on axis diffraction pattern explicitly depends on the square of the window height-to-width ratio. Depending on the value of this parameter, different kinds of axial behavior are observed. In particular, it is found that for low values of this parameter and low Fresnel number, an inverse focal-shift phenomenon can appear.

Image synthesis using the Lau effect

An image synthesizer based on the Lau effect which kes not require any lens and works with spatially incoherent light is implemented. 1.