Open Access
Fiber optic sensor based on fluorescence quenching for heavy metal detection
(IEEE, 2020) Fuentes-Rubio, Yadira A.; Domínguez Cruz, René; Baldovino Pantaleón, Oscar; Ruiz Zamarreño, Carlos; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, we present the preliminary results of a fiber optic sensor based on fluorescence quenching induced by mercury (Hg) concentrations presence in aqueous solutions. The fabrication of the sensor head consists of a methyl red coating over multimode fiber tip using thermoplastic polyurethane to immobilize the thin layer. The sensor device was tested in a Hg molar concentration ranges 10-10,000 nmol/L. The experimental results show a linear dependence of the induced fluorescence quenching related to the Hg molar concentration.
Open Access
Luminescence-based optical sensors fabricated by means of the layer-by-layer nano-assembly technique
(MDPI, 2017) Acha Morrás, Nerea de; Elosúa Aguado, César; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
Luminescence-based sensing applications range from agriculture to biology, including medicine and environmental care, which indicates the importance of this technique as a detection tool. Luminescent optical sensors are required to be highly stable, sensitive, and selective, three crucial features that can be achieved by fabricating them by means of the layer-by-layer nano-assembly technique. This method permits us to tailor the sensors0 properties at the nanometer scale, avoiding luminophore aggregation and, hence, self-quenching, promoting the diffusion of the target analytes, and building a barrier against the undesired molecules. These characteristics give rise to the fabrication of custom-made sensors for each particular application.
Open Access
A comparative study of two different approaches for the incorporation of silver nanoparticles into layer-by-layer films
(Springer, 2014) Rivero Fuente, Pedro J.; Goicoechea Fernández, Javier; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, a comparative study about the incorporation of silver nanoparticles (AgNPs) into thin films is presented using two alternative methods, the in situ synthesis process and the layer-by-layer embedding deposition technique. The influence of several parameters such as color of the films, thickness evolution, thermal post-treatment, or distribution of the AgNPs along the coatings has been studied. Thermal post-treatment was used to induce the formation of hydrogel-like AgNPs-loaded thin films. Cross-sectional transmission electron microscopy micrographs, atomic force microscopy images, and UV-vis spectra reveal significant differences in the size and distribution of the AgNPs into the films as well as the maximal absorbance and wavelength position of the localized surface plasmon resonance absorption bands before and after thermal post-treatment. This work contributes for
Open Access
SnO2-MOF-Fabry-Pérot humidity optical sensor system based on Fast Fourier transform technique
(SPIE, 2016) López Aldaba, Aitor; López Torres, Diego; Ascorbe Muruzabal, Joaquín; Rota Rodrigo, Sergio; Elosúa Aguado, César; López-Amo Sáinz, Manuel; Arregui San Martín, Francisco Javier; Corres Sanz, Jesús María; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
In this paper, a new sensor system for relative humidity measurements based on a SnO2 sputtering deposition on a microstructured optical fiber (MOF) low-finesse Fabry-Pérot (FP) sensing head is presented and characterized. The interrogation of the sensing head is carried out by monitoring the Fast Fourier Transform phase variations of the FP interference frequency. This method is low-sensitive to signal amplitude variations and also avoids the necessity of tracking the evolution of peaks and valleys in the spectrum. The sensor is operated within a wide humidity range (20%-90% relative humidity) with a maximum sensitivity achieved of 0.14rad/%. The measurement method uses a commercial optical interrogator as the only active element, this compact solution allows real time analysis of the data.
Open Access
Design rules for lossy mode resonance based sensors
(Optical Society of America, 2012) Del Villar, Ignacio; Hernáez Sáenz de Zaitigui, Miguel; Ruiz Zamarreño, Carlos; Sánchez Zábal, Pedro; Fernández Valdivielso, Carlos; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
Lossy mode resonances can be obtained in the transmission spectrum of cladding removed multimode optical fiber coated with a thin-film. The sensitivity of these devices to changes in the properties of the coating or the surrounding medium can be optimized by means of the adequate parameterization of the coating refractive index, the coating thickness and the surrounding medium refractive index (SMRI). Some basic rules of design, which enable the selection of the best parameters for each specific sensing application, are indicated in this work.
Open Access
A comprehensive review: materials for the fabrication of optical fiber refractometers based on lossy mode resonance
(MDPI, 2020) Ozcariz Celaya, Aritz; Ruiz Zamarreño, Carlos; Arregui San Martín, Francisco Javier; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA26
Lossy mode resonance based sensors have been extensively studied in recent years. The versatility of the lossy mode resonance phenomenon has led to the development of sensors based on different configurations that make use of a wide range of materials. The coating material is one of the key elements in the performance of a refractometer. This review paper intends to provide a global view of the wide range of coating materials available for the development of lossy mode resonance based refractometers.
Open Access
Study and optimization of self-assembled polymeric multilayer structures with neutral red for pH sensing applications
(Hindawi / Wiley, 2008) Goicoechea Fernández, Javier; Arregui San Martín, Francisco Javier; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The characterization of nanostructured thin films is critical in the design and fabrication of optical sensors. Particularly, this work is a detailed study of the properties of layer-by-layer electrostatic self-assembled multilayer (LbL) structures fabricated using poly(allylamine hydrochloride) (PAH) and Neutral Red (NR) as cations, and poly(acrylic acid) (PAA) as polyanion. These LbL films, due to the colorimetric properties of the NR, are suitable for sensor applications such as pH sensing in the physiological range. In the (PAH+NR/PAA) LbL structure, it has been observed a very important influence of the pH of the solutions in the properties of the resultant films. Different techniques such as spectroscopy and atomic force microscopy (AFM) are combined to characterize the films, and the results are analyzed showing coherence with previous works. The LbL structure is finally optimized and dramatically improved nanostructured films were fabricated, showing good sensing properties, short response times, and good stability.
Open Access
Route towards a label-free optical waveguide sensing platform based on lossy mode resonances
(IFSA Publishing, 2019) Ruiz Zamarreño, Carlos; Zubiate Orzanco, Pablo; Ozcariz Celaya, Aritz; Elosúa Aguado, César; Socorro Leránoz, Abián Bentor; Urrutia Azcona, Aitor; López Torres, Diego; Acha Morrás, Nerea de; Ascorbe Muruzabal, Joaquín; Vitoria Pascual, Ignacio; Imas González, José Javier; Corres Sanz, Jesús María; Díaz Lucas, Silvia; Hernáez Sáenz de Zaitigui, Miguel; Goicoechea Fernández, Javier; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Del Villar, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua,0011-1365-2017- 000117; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA26
According to recent market studies of the North American company Allied Market Research, the field of photonic sensors is an emerging strategic field for the following years and it is expected to garner $18 billion by 2021. The integration of micro and nanofabrication technologies in the field of sensors has allowed the development of new technological concepts such as lab-on-a-chip which have achieved extraordinary advances in terms of detection and applicability, for example in the field of biosensors. This continuous development has allowed that equipment consisting of many complex devices that occupied a whole room a few years ago, at present it is possible to handle them in the palm of the hand; that formerly long duration processes are carried out in a matter of milliseconds and that a technology previously dedicated solely to military or scientific uses is available to the vast majority of consumers. The adequate combination of micro and nanostructured coatings with optical fiber sensors has permitted us to develop novel sensing technologies, such as the first experimental demonstration of lossy mode resonances (LMRs) for sensing applications, with more than one hundred citations and related publications in high rank journals and top conferences. In fact, fiber optic LMR-based devices have been proven as devices with one of the highest sensitivity for refractometric applications. Refractive index sensitivity is an indirect and simple indicator of how sensitive the device is to chemical and biological species, topic where this proposal is focused. Consequently, the utilization of these devices for chemical and biosensing applications is a clear opportunity that could open novel and interesting research lines and applications as well as simplify current analytical methodologies. As a result, on the basis of our previous experience with LMR based sensors to attain very high sensitivities, the objective of this paper is presenting the route for the development of label-free optical waveguide sensing platform based on LMRs that enable to explore the limits of this technology for bio-chemosensing applications.
Open Access
Fabrication of Bragg gratings on the end facet of standard optical fibers by sputtering the same material
(IEEE, 2016) Ascorbe Muruzabal, Joaquín; Corres Sanz, Jesús María; Del Villar, Ignacio; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
A sputtering process has been applied to deposit quarter-wavelength stacks on the end facet of cleaved optical fibers by using only one sputtering target. Standard multimode optical fibers were used as substrates to fabricate broadband filters, and the experimentally measured spectral responses of these devices are shown. Periodical changes in the refractive index of the coating have been achieved by changing the vacuum chamber pressure. A reflected peak with a full-width at half-maximum of 20 nm centered at 440 nm has been obtained, which provides a good structure for the development of optical fiber sensors working with the wavelength detection technique. This optical structure can be used for several purposes: as tunable wavelength filters or optical fiber sensors or to improve the performance of fluorescence sensors. A theoretical analysis of these structures corroborates the experimental results and allows some rules to be obtained.
Open Access
High sensitivity humidity sensor based on cladding-etched optical fiber and lossy mode resonances
(Elsevier, 2016) Ascorbe Muruzabal, Joaquín; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work a high sensitivity optical fiber humidity sensor (OFHS) is presented. The configuration chosen for this purpose is a cladding-etched single mode optical fiber (CE-SMF) coated with a thin film of tin oxide (SnO2). The etching has been made using hydrofluoric acid (HF) and the coating has been fabricated by means of sputtering. Tin oxide was used to build the nano-coating which produces the Lossy Mode Resonance (LMR) and works as sensitive material. Theoretical and experimental results are shown and compared. The device was tested using a climatic chamber in order to obtain the response of the OFHS to relative humidity. Changes greater than 130 nm have been obtained for relative humidity varying from 20% to 90%, which gives a sensitivity of 1.9 nm/%RH.