Walter D. Furlan

Learn More
PURPOSE The relationship between astigmatic refractive errors and their associated visual acuity has been studied in recent years in the context of refractive power space. The influence of the axis of astigmatism remains a matter of controversy. Our goal in this study is to provide additional experimental evidence to clarify this subject. The influence of(More)
A new optical implementation of the Radon-Wigner display for one-dimensional objects is presented, making use of the fractional Fourier transform approach. The proposed setup makes use of only two conventional refractive elements: a cylindrical lens and a varifocal lens. Although the exact magnifications cannot be achieved simultaneously for all the(More)
We propose a new class of one-dimensional (1D) photonic waveguides: the fractal photonic crystal waveguides (FPCWs). These structures are photonic crystal waveguides (PCWs) etched with fratal distribution of grooves such as Cantor bars. The transmission properties of the FPCWs are investigated and compared with those of the conventional 1D PCWs. It is shown(More)
PURPOSE To evaluate the reliability of measuring CS with uncalibrated iPads. METHODS Six random iPads with retina display were calibrated with a colorimeter and the correlation between Luminance (L) and pixel level (y) was computed according to an exponential function. The mean and confidence interval (±2SD) obtained from the six iPads were calculated and(More)
Purpose: To present a new fast and reliable application for iPad (ST) for screening stereopsis at multiple distances. Methods: A new iPad application (app) based on a random dot stereogram was designed for screening stereopsis at multiple distances. Sixty-five subjects with no ocular diseases and wearing their habitual correction were tested at two(More)
Devil's lenses (DLs) were recently proposed as a new kind of kinoform lens in which the phase structure is characterized by the "devil's staircase" function. DLs are considered fractal lenses because they are constructed following the geometry of the triadic Cantor set and because they provide self-similar foci along the optical axis. Here, DLs are(More)
An experimental device to show in a single display all the di rac-tion patterns generated by a 1D fractal structure is proposed. It is found that in addition to being the optimum display to see the evolution of the di racted eld through free space, some interesting features, such as continuous evaluation of self-similarity from the object to the far eld,(More)
An optical setup to obtain all the fractional correlations of a one-dimensional input in a single display is implemented. The system works as a multichannel parallel correlator for a continuous set of fractional orders and presents a variable shift variance. Some experimental results together with computer simulations are performed to illustrate the(More)
  • 1