Person: González Cano, Agustín
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First Name
Agustín
Last Name
González Cano
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
13 results
Search Results
Now showing 1 - 10 of 13
Item Moving the wavelength detection range in surface plasmon resonance sensors based on tapered optical fibers(Fourth European Workshop on Optical Fibre Sensors, 2010) Díaz Herrera, Natalia; González Cano, Agustín; Viegas, Diana Catarino das Neves; Santos, José Luis; Navarrete Fernández, María Cruz; Esteban Martínez, ÓscarIt is shown how the design possibilities offered by double-layer uniform-waist tapered optical fibers (DLUWTs) permit to move the wavelength detection range to adapt the response of the sensors to varied conditions. In particular, we have obtained very good experimental curves showing that we can achieve plasmon resonances in the C-band of the optical communications, around 1.5 μm, for the range of refractive indices of aqueous media, highly interesting in the biosensors field. Also, we show results for other interesting wavelength region, around 500 nm, where we can take advantage of the absorption peaks of the analytes. Finally, we explore the possibilities of using InN as a dielectric material for the second layer of the deposition. These results contribute to considerably expand the applicability and performance of SPR fiber sensors.Item Miniature Fiber Bragg Grating Strain Rosette Based on Lossless Tapers(21st International Conference on Optical Fiber Sensors, 2011) Viegas, Diana Catarino das Neves; Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, Agustín; Santos , Jose Luis; Araújo, Fernanda MendesA miniature fiber Bragg grating strain rosette is presented. The proposed design is made possible through the development of low curvature radius lossless tapers, thus offering advantages in miniaturization of the rosette configuration. We report on the experimental validation of the miniature rosette design, demonstrating its effective operation.Item Uniform-waist tapered optical fibers with double-layer deposition.(Second European Workshop On Optical Fibre Sensors: Proceedings, 2004) González Cano, Agustín; Díaz Herrera, Natalia; Navarrete Fernández, María Cruz; Esteban Martínez, Óscar; Bueno Guillén, Francisco JavierNovel devices consisting of uniform-waist tapered optical fibers with a double layer (metal plus dielectric) deposition are presented and their properties in terms of optical transmission are studied. Excitation of surface plasmons in the metallic layers is experimentally shown. These devices can be used as basis for new sensors.Item Phase measurement method for stress analysis from photoelastic data(Iutam Symposium On Advanced Optical Methods and Applications in Solid Mechanics, 2000) Quiroga Mellado, Juan Antonio; González Cano, AgustínIn recent years, phase measuring techniques have been applied to the problem of extracting information from photoelastic data. In this work, a complete method for stress analysis from photoelastic fringe patterns is presented. The photoelastic phase maps are obtained with a circular polariscope. For the isoclinics calculation a four-step phase-shift algorithm is used. A white light source is used to avoid problems of low modulation in the fringe pattern. Isochromatics are calculated by a new algorithm developed by us that overcomes the problems associated to low modulation areas produced by isoclinics. The isochromatic parameter can be determined without sign ambiguity. We have also developed a method for analysis of the measurement errors produced by errors in the elements of the polariscope. Finally, using the equilibrium equations, we can obtain the values of the main stresses in the sample from the isoclinic and isochromatic parameters.Item An experimental evaluation of the behavior of SPR fiber sensors in absorptive medium when plasmons are tuned to absorption peak: method for selective measurement(21st International Conference on Optical Fiber Sensors, 2011) Leite, I.; Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, Agustín; Esteban Martínez, ÓscarIn this work we present experimental results that confirm the influence of an absorptive surrounding medium in the behavior of conventional SPR fiber sensors. It can be observed that when a plasmon resonance coincides with a wavelength absorbed by the medium, the depth of the dip is affected, as predicted in the simulations. The results are important from the basic point of view, since the influence of absorptive medium in plasma waves has not been sufficiently studied up to date and they can also be used as the basis for a new method of SPR-based refractometry selective to specific analytes without the need of the addition of recognizing elements to the transducer.Item Application of regularization methods to the analysis of photoelastic fringe patterns(Interferometry 99: Techniques and Technologies, 1999) Quiroga Mellado, Juan Antonio; González Cano, AgustínIn this work we present the application of a regularization algorithm to the processing of photoelastic hinge patterns. The method used is a modified phase tracking algorithm applied to phase-shifted images. In particular, we present an algorithm for isoclinics-isochromatics separation that uses only five images. The performance of the method is discussed and experimental results are presented.Item Fiber-optic salinity probe(Second European Workshop On Optical Fibre Sensors: Proceedings, 2004) Díaz Herrera, Natalia; Esteban Martínez, Óscar; Navarrete Fernández, María Cruz; González Cano, AgustínAn optical-fiber salinometer has been evaluated during a two-week measurement campaign in the Baltic Sea. The obtained results in three different tests are presented in comparison with those obtained with a standard electric CTD sonde commercially available.Item On the dependence on isoclinics of the modulation of isochromatic phase maps(Optik, 1999) Quiroga Mellado, Juan Antonio; González Cano, AgustínIn this work we evaluate the dependence on isoclinics of the modulation of the isochromatic phase maps when phase-shifting algorithms are applied to experiments of photoelasticity. This dependence makes conventional phase-shifting algorithms unsuitable for that application.Item Improved performance of SPR optical fiber sensors with InN as dielectric cover(21st International Conference on Optical Fiber Sensors, 2011) Esteban Martínez, Óscar; Naranjo Vega, Fernando Bernabé; Díaz Herrera, Natalia; Valdueza Felip, Sirona; Navarrete Fernández, María Cruz; González Cano, AgustínIn this work, the performance of uniform-waist tapered optical fiber sensors based on SPR with Indium Nitride (InN) as dielectric layer has been experimentally studied. The obtained results show that the overall performance in terms of reliability, long term stability and sensitivity is improved. Furthermore, the dependence of the sensitivity with the thickness of the dielectric layer is also studied, showing that increases as the thickness decreases while the well known trend to excite the surface plasmons at longer wavelengths or higher refractive index of the outer medium is kept. Thus, a novel application of the InN to optical fiber sensors is demonstrated. The use of this material would be of great interest to produce new, improved, SPR-based devices for chemical and biological sensing.Item Fiber-optics sensor for in situ salinity measurement.(14th International Conference On Optical Fiber Sensors, 2000) Esteban Martínez, Óscar; Navarrete Fernández, María Cruz; González Cano, Agustín; Bernabeu Martínez, EusebioThe degree of salinity of water is measured by determining its refractive index with a fiber-optics sensor. The physical principle of the device is the attenuation of the optical power guided by the fibre by the resonant coupling with surface plasmons of a metal layer deposited on the polished cladding of the fibre. The linearity and accuracy of the sensor make it suitable for in situ measurements.