Search

Your search keyword '"Otón, José M."' showing total 12 results
Start Over Author "Otón, José M." Search Limiters Available in Library Collection
12 results on '"Otón, José M."'

1. Low-Impact Air-to-Ground Free-Space Optical Communication System Design and First Results

Author

Carrasco-Casado, Alberto, Oton, Eva, Vergaz, Ricardo, Geday, Morten A., Sanchez-Pena, Jose M., and Oton, Jose M.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

An air-to-ground free-space optical communication system has been designed and partially developed. The design covers both the communications between the airborne and the ground station, and the acquisition, tracking and pointing. A strong effort has been made in order to achieve the minimum payload power, size and weight, for which a MEMS modulating retroreflector has been chosen. In the ground station, a new technique for fine pointing, based on a liquid crystal device, is proposed and will be demonstrated, as well as other improvements with the aim of optimizing the ground station performance., Comment: 4 pages, 9 figures, IEEE 2011 International Conference on Space Optical Systems and Applications (ICSOS). arXiv admin note: substantial text overlap with arXiv:1506.08854

Published
2015
Full Text
View/download PDF

2. Aggregation-induced emission enhancement (AIEE)-active Pt(II) metallomesogens as dyes sensitive to Hg2+ and dopant agents to develop stimuli-responsive luminescent polymer materials

Author

Cuerva De Alaiz, Cristian, Campo Santillana, José Antonio, Cano Esquivel, María Mercedes, Caño-García, Manuel, Otón, José M., Lodeiro, Carlos, Cuerva De Alaiz, Cristian, Campo Santillana, José Antonio, Cano Esquivel, María Mercedes, Caño-García, Manuel, Otón, José M., and Lodeiro, Carlos

Abstract

The luminescence properties of Pt(II) compounds can be modulated by controlling the assembly of their molecules both in the solution and in the solid state. This fact constitutes a powerful tool for developing materials with stimuli-responsive luminescence properties. Herein, we describe the self-assembly behaviour of several series of Pt(II) metallomesogens in two different media upon controlled conditions. On the one hand, we explore the ability of several metal cations to induce the formation of Pt⋯Pt aggregates in solution, with the main goal of enhancing the phosphorescent emission of these compounds. On the other hand, since these compounds exhibit liquid crystalline mesophases and the temperature can control the aggregation, we have fabricated Pt(II) compound-doped polymer films and silicone membranes that show stimuli-responsive luminescent properties. In both cases, the interactions between the Pt(II) compounds and the metal cations, or the polymer matrices, play a key role in the aggregation-induced emission enhancement (AIEE) behaviour of the dyes. The effects of the alkyl chain length, the molecular asymmetry, and the nature of the ligands in the establishment of these interactions are also evaluated., Ministerio de Economía y Competitividad, MINECO/FEDER (Spain), project CTQ2015-63858-P, PROTEOMASS Scientific Society (Portugal), Associate Laboratory for Green Chemistry-LAQV/REQUIMTE, FCT/MEC (Portugal), project UID/QUI/50006/2013, Universidad Complutense de Madrid-Santander Universidades (Spain), Fundación Alfonso Martín Escudero (Spain), Ministerio de Economía y Competitividad (Spain) and European Social Fund - BES-2014-070964, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Published
2024

5. Optimizing Tunable LC Devices with Twisted Light.

Author

Otón, José M., Pereiro-García, Javier, Quintana, Xabier, Caño-García, Manuel, Otón, Eva, and Geday, Morten A.

Subjects
LIQUID crystal devices, ANGULAR momentum (Mechanics)
Abstract

Tunable circular devices made of liquid crystals or other materials, like lenses, axicons, or phase plates, are often constrained by limitations in size, tunability, power, and other parameters. These constraints restrict their use and limit their applicability. In this review, a thorough study of the use of light's orbital angular momentum in the manufacturing of liquid crystal (LC) devices is presented. Twisted light fosters the simultaneous optimization of most critical parameters. Experimental demonstrations of the unmatched performance of tunable LC lenses, axicons, and other elements in parameters such as lens diameter (>1″), power and tunability (>±6 diopters), fill factor (>98%), and time response have been achieved by reversible vortex generation created by azimuthal phase delay. This phase delay can eventually be removed within the optical system so that lens performance is not affected. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

12. Electrical Model for Thresholdless Antiferroelectric Liquid Crystal Cells

Author

Sánchez-Pena, José Manuel, Pérez Garcilópez, Antonia Isabel, Rodríguez, Isabel, Vázquez García, María Carmen, Urruchi del Pozo, Virginia, Quintana, X., Frutos Andreu, Juan José, and Otón, José M.

Subjects
Antiferroelectric liquid cristal, Hysteresis, Electrical model, Electrónica, V-shape switching
Abstract

The equivalent circuit for a thresholdless antiferroelectric liquid crystal (TLAFLC) cell has been derived using an electrical model. The model may be used to predict the TLAFLC dynamic behavior. The electrical response in the time domain of TLAFLC cells upon certain hypothesis has been obtained. Optical characteristics related to these electrical features have been derived as well. The equivalent circuit model reasonably reproduces the voltage across the cell, switching currents and the optical hysteresis obtained by experimental methods. The procedure for determining the voltage-dependent capacitance due to induced spontaneous polarization is shown. On the basis of the proposed model, we also suggest a number of clues to optimize some electrical parameters of liquid crystal materials as well as driving schemes. Publicado

Published
2002

Catalog

Books, media, physical & digital resources
See catalog results