Person:
Canabal Boutureira, Héctor Alfonso

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First Name
Héctor Alfonso
Last Name
Canabal Boutureira
URI
https://hdl.handle.net/20.500.14352/79958
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
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1998 - 199912000 - 20011
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Author: Alonso Fernández, José × End date: 2019 ×

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Now showing 1 - 2 of 2
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    A generalization of Prentice's law for lenses with arbitrary refracting surfaces
    (Ophthalmic & Physiological Optics (OPO), 1998) Canabal Boutureira, Héctor Alfonso; Gómez Pedrero, José Antonio; Alonso Fernández, José; Bernabéu Martínez, Eusebio
    A generalization of the Prentice's law is presented in this paper. The idea consists of removing some (but not all) of the approximations that comprise the paraxial approach. In that way, we obtain a new formulation that permits us to compute the prismatic power of a lens made up of arbitrary refracting surfaces, and to improve the precision obtained by Prentice's law when applied to monofocal lenses. The resulting formalism is simple and manageable and its derivation leads us to a precise definition of the local dioptric power matrix, introduced in a previous paper, as well as a better understanding of the same.
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    Laser beam deflectometry based on a subpixel resolution algorithm
    (Optical Engineering, 2001) Canabal Boutureira, Héctor Alfonso; Alonso Fernández, José; Bernabéu Martínez, Eusebio
    A deflectometric method for the characterization of optical systems is presented. It is based on the use of a CCD camera and a subpixel resolution algorithm for the measurement of the deflection of a laser beam that propagates through the system. To obtain accurate results, three different algorithms for measuring the position of the deflected beam are tested and compared. Based on this comparison, an algorithm based on the calculation of the phase of the fast Fourier transform (FFT) is selected, and an accuracy of 0.024 pixels is obtained on the determination of the beam position in our setup. Using an XY scanning stage, the proposed method is completely automated and applied for the characterization of ophthalmic lenses. In this application, the gradients of the wavefront refracted by the lens are measured directly, and from them, the thickness and the local power of the lens are computed.