Person: Navarrete Fernández, María Cruz
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First Name
María Cruz
Last Name
Navarrete Fernández
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Óptica
Area
Optica
Identifiers
31 results
Search Results
Now showing 1 - 10 of 31
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 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 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.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 Theoretical method for the study of plasmon generation in hybrid multilayer-optical fiber structures(IEEE Sensors Journal, 2005) Esteban Martínez, Óscar; Navarrete Fernández, María Cruz; González Cano, AgustínA theoretical method is presented for the determination of the behavior of devices based on the deposition of multilayer structures on polished optical fibers. Plasmon generation in metallic layers is modeled. The method is based on the Rayleigh expansion of the electric fields and permits us to determine their distribution over the whole structure by an application of boundary conditions. Once the distribution is known, the power transmitted by the fiber can be computed as a function of the geometrical and refractive parameters of the device. The method is versatile and can be used as a theoretical tool for the design of devices of that type used for many different purposes. We present real experimental results obtained with an operative sensor that agree with the theoretical predictions of our technique and prove its suitability.Item Surface plasmon resonance sensors based on uniform-waist tapered fibers in a reflective configuration(Applied Optics, 2006) Esteban Martínez, Óscar; Díaz Herrera, Natalia; Navarrete Fernández, María Cruz; González Cano, AgustínWe present a configuration for surface plasmon resonance sensors based on uniform-waist tapered optical fibers and reflective elements. Once the fiber is tapered fulfilling the adiabatic criterion, a multilayer including a metallic medium is asymmetrically deposited on the uniform waist of the fiber. This feature provides the resonant excitation of multiple surface plasma waves. In addition, a mirror is produced at the fiber tip by a chemical Tollens reaction. In this way, the sensor operates in a reflective mode, more convenient for dip probes. When these sensors are spectrally interrogated, a high sensitivity of 10^4 refractive index units per nanometer is attained. These devices can be advantageously used for any kind of chemical sensing and biosensing.