Person:
Díaz Herrera, Natalia

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First Name
Natalia
Last Name
Díaz Herrera
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
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UCM identifierORCIDScopus Author IDDialnet ID

Search Results

Now showing 1 - 10 of 21
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    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, Óscar
    We 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.
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    Extension of Surface Plasmon Resonance in fiber optic sensors into the visible region
    (Fifth European Workshop On Optical Fibre Sensors, 2013) Navarrete Fernández, María Cruz; Díaz Herrera, Natalia; González Cano, Agustín; Esteban Martínez, Óscar
    In this work we experimentally show how the technology of surface plasmon resonance (SPR) in doubly deposited uniform-waist tapered optical fiber sensors (DLUWTs) can be extended into the visible region (around 520 nm) by changing the thicknesses of the deposited layers. In this way, by using DLUWTs we can cover, in an easy and versatile way, a total wavelength range over 1000 nm wide, having shown in the past how this same kind of sensors can be usable in the communication band. The possibilities of fiber sensors can then be applied to the region of visible wavelengths, which is very interesting from the biological point of view.
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    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, Agustín
    We 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.
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    Improved performance of SPR sensors by a chemical etching of tapered optical fibers
    (Optics and Lassers in Engineering, 2011) Díaz Herrera, Natalia; Esteban Martínez, Óscar; Navarrete Fernández, María Cruz; González Cano, Agustín; Benito Peña, María Elena; Orellana Moraleda, Guillermo
    We present the results of a chemical attack on the optical fiber surface previous to the deposition of the double layer (metal plus dielectric) in Double-layer uniform-waist tapered fibers (DLUWTs) used for the development of SPR sensors. It is shown how this simple chemical treatment increases the roughness of the surface and permits improvement of the stability of the deposits and the general performance of the sensors. The obtained devices are robust and very compact, their sensitivity is good and repeatability of the measurements is remarkably increased. The procedure can be useful for any fiber-optic sensor.
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    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 Mendes
    A 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.
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    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, Ivo
    Conventional 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.
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    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, Óscar
    It 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.
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    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, Boris
    A 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.
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    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 Cruz
    Experimental 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.
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    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, Óscar
    In 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.