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
14 results
Search Results
Now showing 1 - 10 of 14
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 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 Selectivity of SPR fiber sensors in absorptive media: An experimental evaluation(Sensors and Actuators B - Chemical, 2011) Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, Agustín; Esteban Martínez, Óscar; Leite, IvoConventional surface plasmon resonance (SPR) fiber sensors show selective behavior when resonance wavelengths are tuned to absorption peaks of the surrounding medium, as it is experimentally shown and evaluated in this paper by using a doubly-deposited uniform-waist tapered optical fiber (DLUWT) and a dye as a test material. This behavior is clearly distinguishable from the usual response to nonabsorbing media and can be used to develop a new concept of SPR transducers. At the same time, the obtained results, which are in accordance with the theoretical predictions permit to increase the basic knowledge on surface plasma waves excitation in optical fibers.Item Plasmonic sensor based on tapered optical fibers and magnetic fluids for measuring magnetic fields(Sensors and actuators A - Physical, 2017) Rodriguez Schwendtner, E.; Díaz Herrera, Natalia; Navarrete Fernández, María Cruz; González Cano, Agustín; Esteban Martínez, ÓscarWe present a new sensor based on the combination of Surface Plasmon Resonance (SPR) with magneto-refractive materials. We use doubly-deposited uniform-waist tapered optical fibers (DLUWTs), that have shown their good performance and versatility as refractometers, and magnetic fluids as transducers to measure magnetic fields in an all-optical-fiber configuration. We experimentally show the feasibility of our approach, by demonstrating the physical principle of the device and characterizing the performance of the sensors, which show very good sensitivity and resolution. In this way, we propose a new field of development for SPR optical fiber sensors to extend the field of application of the plasmonics-based technologies.Item Surface plasmon resonance in the visible region in sensors based on tapered optical fibers(Sensors and Actuators B - Chemical, 2014) Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, Agustín; Esteban Martínez, ÓscarDoubly deposited uniform-waist tapered optical fibers (DLUWTs) have shown their versatility and good performance as basis for surface plasmon resonance (SPR) sensors for a variety of wavelength ranges. In this work we experimentally show how these devices can be employed to extend the technology of SPR fiber sensors to the visible region, down to about 530 nm, with remarkable results in terms of sensitivity, plasmon definition and the availability of multiple plasmon resonances for each configuration. In this way, DLUWTs can be used to cover a range of more than 1000 nm for aqueous media only by changing the thickness of the deposits. Also, it is shown how these results can be used with the so-called absorption method to make selective the response of the sensors and a study is made on the influence of the taper waist in the performance of the devices. The number of SPR fiber sensors working in the visible region, of great interest in biological research, that have been depicted in the literature is very small, and the sensors that we present here notably improve their performance.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 Microfiber as light source for exciting fluorescence in a polymer optical fiber(Sensors and Actuators B - Chemical, 2016) Rodriguez Schwendtner, E.; Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; Esteban Martínez, Óscar; González Cano, AgustínWe present a new technique for exciting and collecting fluorescence with all-fiber devices, consisting of two different tapered fibers, a microfiber used as illuminating source and a polymer optical fiber where a fluorophore has been deposited and where the fluorescence takes place. We depict the fabrication of the device, characterize its performance and show the feasibility of our approach, the good performance obtained and the possibility of using the flexibility of the illuminating fiber to increase this performance and the compactness of the device.Item Advanced Plasmonic Fiber-Optic Sensor for High Sensitivity Measurement of Magnetic Field(IEEE Sensors journal, 2019) Rodriguez Schwendtner, Eva María; Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, Agustín; Esteban Martínez, ÓscarAn advanced plasmonic sensor for high sensitivity measurement of magnetic field is presented. It is based on the combination of a SPR refractometer (doubly-deposited tapered optical fiber) with magnetic fluids used as transducers. The device is compact and robust and has been theoretically analyzed and completely characterized, showing a very good experimental performance. We have studied the dependence of the response of the device with the direction of the field, confirming that, as expected, the sense of the variation of the refractive index is opposite for parallel and perpendicular fields, which is an interesting feature for practical applications. We have also evaluated the dependence on the concentration of the employed magnetic fluid and the influence of the chosen type of ferrofluid. In all these measurements the sensitivity experimentally obtained is amongst the highest reported in the literature for this kind of devices and we have extended the dynamic range. Finally, we have applied a novel, auto-referential, signal processing algorithm to the measurements, showing its possibilities. The obtained experimental results demonstrate the feasibility and the advantages of the application of SPR fiber-optic sensors to magnetic field measurements.Item A Polarization-Independent SPR Fiber Sensor(Plasmonics, 2010) Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, Agustín; Esteban Martínez, ÓscarThe resonance of surface plasma waves in metallic layers is a strongly polarization-dependent phenomenon by the very nature of the physical effect responsible of that resonance. This implies the necessity of polarization-controlling elements to be added to any operative surface-plasmon-resonance-based sensor. A fully symmetrical, circular-section double deposition of a metallic and a dielectric layer on a uniform-waist tapered optical fiber (SymDL-UWT) permits us to completely eliminate the dependence on polarization of the plasmon excitation, with the corresponding operative advantages and basic theoretical consequences. We depict the fabrication process of these transducers, which is based on the use of a simple and efficient rotating element developed by us, and show the characteristics of the produced devices. No such device has been depicted up to date. As our experimental results show, this kind of devices can be considered a very good option for the development of simple, compact, and efficient chemical and biological sensors.Item High-sensitive SPR sensing with Indium Nitride as a dielectric overlay of optical fibers(Sensors and Actuators B - Chemical, 2011) Esteban Martínez, Óscar; Díaz Herrera, Natalia; Naranjo Vega, Fernando Bernabé; Valdueza Felip, Sirona; Navarrete Fernández, María Cruz; González Cano, AgustínIn this work, an Indium Nitride (InN) dielectric overlay has been used to develop a surface plasmon resonance optical fiber sensor. Although InN is a very promising material in electronics industry, this is the first time that this kind of material is used for optical sensing. The obtained results show an improvement of the reliability and long term stability with respect to previous devices made with the same technology. More remarkably, the sensitivity increases up to 11,800 nm/RIU in the range of outer refractive indices between 1.415 and 1.429, the highest sensitivity achieved with this kind of devices. Therefore, 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 SPR-based devices for chemical and biological sensing.