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
52 results
Search Results
Now showing 1 - 10 of 52
Item Deposition of Graphene Oxide on an SPR Fiber Refractometer for Sensor Applications(Sensors, 2023) Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, AgustínGraphene-based materials have been increasingly incorporated to optical fiber plasmonic sensors due to the peculiar physical and chemical properties of these materials (hardness and flexibility, high electrical and thermal conductivity, and very good adsorption for many substances, etc.). In this paper, we theoretically and experimentally showed how the addition of graphene oxide (GO) to optical fiber refractometers permits the development of surface plasmon resonance (SPR) sensors with very good characteristics. We used doubly deposited uniform-waist tapered optical fibers (DLUWTs) as supporting structures because of their already proven good performance. The presence of GO as an effective third layer is useful to tune the wavelength of the resonances. In addition, the sensitivity was improved. We depict the procedures for the production of the devices and characterize the GO+DLUWTs produced in this way. We also showed how the experimental results are in agreement with the theoretical predictions and used these to estimate the thickness of deposited GO. Finally, we compared the performance of our sensors with other ones that have been recently reported, showing that our results are among the best reported. Using GO as the medium in contact with the analyte, in addition to the good overall performance of devices, permit consideration of this option as an interesting possibility for the future development of SPR-based fiber sensors.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 Generation of Surface Plasmons at Waveguide Surfaces in the Mid-Infrared Region(Plasmonics, 2012) Díaz Herrera, Natalia; González Cano, Agustín; Esteban Martínez, Óscar; Navarrete Fernández, María Cruz; Mizaikoff, BorisA technique is proposed to extend the application of surface-plasmon-based spectroscopy into the mid-infrared spectral regime, which is of substantial interest in the field of chemical analysis and biosensing. Surface plasmons can be excited for wavelengths of the order of 6 μm at corrugated waveguides for a given combination of materials and thicknesses, and for refractive indices of the surrounding medium corresponding to those of organic solvents. This approach can easily be extrapolated to other values of any of these parameters. Based on these considerations, a new generation of mid-IR SPR sensors can be developed with a diverse range of potential applications in chem/bio sensing.Item Interferencias de ondas esféricas por reflexiones múltiples en láminas transparentes : sensor óptico para el control automático de espesor(2002) González Cano, Agustín; Bernabeu, E.Se desarrollan modelos teóricos y resultados experimentales para la construcción de un sensor óptico interferencial para el control automático del espesor de laminas transparentes. El modelo teórico permite plantear el problema en términos abstractos para muestras de geometría e índice de refracción arbitrarios, bajo diversas aproximaciones, se ha podido llegar a una relación sencilla entre el periodo espacial de las franjas del interferograma y el espesor de la muestra. También se ha desarrollado un software especifico que, basándose en un método original de reducción de franjas, permite conocer el periodo espacial de un interferograma de modo automático. A partir de estos resultados, se ha construido un dispositivo experimental simple y de bajo coste, que puede ser útil para usos industriales.Item Refractive index sensing of aqueous media based on plasmonic resonance in tapered optical fibres operating in the 1.5 μm region(Sensors and Actuators B, Chemical, 2010) Díaz Herrera, Natalia; González Cano, Agustín; Viegas, Diana Catarino das Neves; Santos, José Luis; Navarrete Fernández, María CruzExperimental results are shown demonstrating that multiple surface plasma waves can be excited in optical fibres at the 1.5 μm optical communications region for the range of refractive indices of aqueous media using doubly deposited tapered fibre structures, well known to exhibit small or zero sensitivity to polarization. Well-defined plasmon dips were obtained with high sensitivity to the surrounding refractive index. This characteristic, together with the substantial flexibility for local and distributed measurement associated with optical fibre sensing supported by the C-Band technology, indicate that these devices can be very advantageously used for chemical, biological and environmental sensing.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 Measurement of the degree of salinity of water with a fiber-optic sensor(Applied Optics, 1999) Esteban Martínez, Óscar; Navarrete Fernández, María Cruz; González Cano, Agustín; Bernabeu Martínez, EusebioA fiber-optic sensor based on surface-plasmon resonance for the determination of the refractive index is used for measuring the degree of salinity of water. The transducing element consists of a multilayer structure deposited on a side-polished monomode optical fiber. Measuring the attenuation of the power transmitted by the fiber shows that a linear relation with the refractive index of the outer medium of the structure is obtained. The system is characterized by use of a varying refractive index obtained with a mixture of water and ethylene glycol. Experimental results show that the sensor can be used as a salinity-degree measurement device with environmental applications.Item A fast method to measure the irradiance response of image processing systems(Measurement Science and Technology, 1995) Quiroga Mellado, Juan Antonio; González Cano, Agustín; Bernabeu Martínez, EusebioA method to estimate in a fast and simple way the response of an image acquiring system (such as a charge-coupled device camera plus an image-processing board) for a monochromatic light source is presented. Two images, whose irradiances are related in a known way, are acquired, and the corresponding grey levels of the responses of the system are correlated pixel to pixel. From this correlation and the relationship between the irradiances of the images, a relative estimation of the irradiance response of the system can be obtained by means of simple algorithms. This method is fast and easy to implement and the results obtained are satisfactory.Item Simple model of compound waveguide structures used as fiber-optic sensors(Optics and Lassers in Engineering, 2000) Esteban Martínez, Óscar; Navarrete Fernández, María Cruz; González Cano, Agustín; Bernabeu Martínez, EusebioIn this work we present an application of a simple quasi-geometrical model to analyze the behavior of compound waveguide structures used as fiber-optic sensors. This theoretical model is based on the adjustment of the parameters of the structure from the experimental measures to predict the observed behavior of the device. It also takes into account the non-monocromaticity of the used source. In this way, it can be used as a design criterion for this kind of structures. It is applied to a refractive index fiber-optic sensor based on the excitation of surface plasmon in a metal layer by the light guided by a monomode fiber.