Person:
Sánchez Brea, Luis Miguel

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First Name
Luis Miguel
Last Name
Sánchez Brea
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Óptica
Area
Optica
Identifiers
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Now showing 1 - 3 of 3
  • Publication
    Diffractive optical elements with square concentric rings of equal width
    (John Wiley & Sons INC, 2010-04) Alda, Javier; Sánchez Brea, Luis Miguel; Salgado Remacha, Francisco Javier; Rico-García, José María
    A diffractive optical element having equal-width concentric square rings is analyzed in this article. This constant width makes possible its realization using spatial light modulators or square pixels phase screens. It allows a simple analytical treatment, and the element is also simulated using the Rayleigh-Sommerfeld approach. An experimental verification of its performance has been compared with the simulated results.
  • Publication
    Optimal phase distributions for polygonal Fresnel lenses
    (IEEE, 2010) Alda, Javier; Salgado Remacha, Francisco Javier; Sánchez Brea, Luis Miguel; Rico-García, José María; González, Francisco Javier
    Polygonal Fresnel zone plates can be configured in a variety of forms depending on the number of sides of the polygon and the number of phase steps used. This contribution deals with some specific polygonal designs that tessellate the plane: triangles, squares, and hexagons. The phase distribution is chosen as a continuous one to form a polygonal kinoform. The selected designs have been simulated and its behaviour compared. Although their performance is worse than the circular Fresnel plate, they may present some other advantages as the tessellation capability, and the possibility to fabricate them as extruded profiles.
  • Publication
    Optimized square Fresnel zone plates for microoptics applications
    (SPIE, 2009-06-17) Rico-García, José María; Salgado Remacha, Francisco Javier; Sánchez Brea, Luis Miguel; Alda, Javier
    Polygonal Fresnel zone plates with a low number of sides have deserved attention in micro and nanoptics, because they can be straightforwardly integrated in photonic devices, and, at the same time, they represent a balance between the high-focusing performance of a circular zone plate and the easiness of fabrication at micro and nano-scales of polygons. Among them, the most representative family are Square Fresnel Zone Plates (SFZP). In this work, we propose two different customized designs of SFZP for optical wavelengths. Both designs are based on the optimization of a SFZP to perform as close as possible as a usual Fresnel Zone Plate. In the first case, the criterion followed to compute it is the minimization of the difference between the area covered by the angular sector of the zone of the corresponding circular plate and the one covered by the polygon traced on the former. Such a requirement leads to a customized polygon-like Fresnel zone. The simplest one is a square zone with a pattern of phases repeating each five zones. On the other hand, an alternative SFZP can be designed guided by the same criterion but with a new restriction. In this case, the distance between the borders of different zones remains unaltered. A comparison between the two lenses is carried out. The irradiance at focus is computed for both and suitable merit figures are defined to account for the difference between them.