Open Access
Single-mode-multimode-single-mode and lossy mode resonance-based devices: a comparative study for sensing applications
(Springer-Verlag, 2015) Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Corres Sanz, Jesús María; Del Villar, Ignacio; Hernáez Sáenz de Zaitigui, Miguel; Socorro Leránoz, Abián Bentor; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC
Open Access
Tapered single-mode optical fiber pH sensor based on lossy mode resonances generated by a polymeric thin-film
(IEEE, 2012) Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Lossy mode resonances can be generated with certain polymeric nanostructures, such as those obtained with a multilayered assembly of poly(allylamine hydrochloride) and poly (acrylic acid). This coating is adsorbed by the electrostatic self assembly technique onto a tapered single-mode optical fiber, in order to evaluate its performance when detecting pH. According to the results reported in this work, the high sensitivity given by a tapering process in a single-mode optical fiber is increased by the effect of this kind of electromagnetic resonances. Particularly, in a pH range from 4.0 to 6.0 the overall wavelength shift of this sensor reaches 200 nm and the transmission at the resonance wavelengths can fall down to -50 dB. These data provide results which can be taken into account to detect pH with high accuracy.
Open Access
Fiber-optic biosensor based on lossy mode resonances
(Elsevier, 2012) Socorro Leránoz, Abián Bentor; Corres Sanz, Jesús María; Del Villar, Ignacio; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Open Access
Fiber-optic immunosensor based on lossy mode resonances induced by indium tin oxide thin-films
(IEEE, 2017) Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC
A novel immunosensor based on lossy mode resonances (LMRs) induced in optical fibers is developed in this contribution. Indium tin oxide (ITO) is sputtered on the optical substrate to generate an LMR in the transmission spectrum. Type G immunoglobulins (IgGs) are then attached to the ITO-coated fiber using (3-glycidyloxypropyl)trimethoxysilane (GPTMS). A phosphate buffer saline solution containing anti-IgGs is used to detect the biological reactions. The presented device is capable of detecting anti-IgG concentrations up to 10 nM. These results will permit the fabrication of biosensors based on a covalent attachment of bioreceptors over an LMR inducing thin-film.
Open Access
A comparative study between SMS interferometers and lossy mode resonace optical fiber devices for sensing applications
(SPIE, 2015) Socorro Leránoz, Abián Bentor; Hernáez Sáenz de Zaitigui, Miguel; Del Villar, Ignacio; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Optical fiber sensors are of great interest due to their intrinsic advantages over electronic sensors. In this work, the sensing characteristics of two different and novel optical fiber devices are compared, after simultaneously depositing a thin-film using the layer-by-layer assembly deposition process. The first one is an SMS structure, formed by splicing two single-mode fiber pigtails on both sides of a coreless multimode fiber segment. This structure induces an interferometric phenomenon that generates several attenuation and transmission bands along the spectrum. These bands are sensitive to variations in the surrounding refractive index, although this sensitivity has been enhanced by a TiO2/PSS thin-film. The other device is a 40 mm uncladded segment of a 200 µm-core multimode optical fiber. When coated by a TiO2/PSS thinfilm, part of the light transmitted into the uncladded core is coupled into the thin-film, generating a lossy mode resonance (LMR). The absorption peaks due to these phenomena red-shift as long as the thin-film thickness increases or the external RI becomes higher. The performance of these devices as refractometers and relative humidity sensors are tested. Results show that the LMR-based sensor is more sensitive in both situations, in spite of its lower sensitivity. Particularly, it presents a 7-fold sensitivity enhancement when measuring surrounding medium refractive index changes and a 10-fold sensitivity enhancement when measuring environmental relative humidity. To our knowledge, this is the first time that a comparative study between SMS and LMR sensors is performed.
Open Access
Recent developments in fiber optics humidity sensors
(MDPI, 2017) Ascorbe Muruzabal, Joaquín; Corres Sanz, Jesús María; 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 wide range of applications such as health, human comfort, agriculture, food processing and storage, and electronic manufacturing, among others, require fast and accurate measurement of humidity. Sensors based on optical fibers present several advantages over electronic sensors and great research efforts have been made in recent years in this field. The present paper reports the current trends of optical fiber humidity sensors. The evolution of optical structures developed towards humidity sensing, as well as the novel materials used for this purpose, will be analyzed. Well-known optical structures, such as long-period fiber gratings or fiber Bragg gratings, are still being studied towards an enhancement of their sensitivity. Sensors based on lossy mode resonances constitute a platform that combines high sensitivity with low complexity, both in terms of their fabrication process and the equipment required. Novel structures, such as resonators, are being studied in order to improve the resolution of humidity sensors. Moreover, recent research on polymer optical fibers suggests that the sensitivity of this kind of sensor has not yet reached its limit. Therefore, there is still room for improvement in terms of sensitivity and resolution.
Open Access
Spectral width reduction in lossy mode resonance-based sensors by means of tapered optical fibre structures
(Elsevier, 2014) Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Open Access
Optimization of sensors based on multimode interference in single-mode–multimode– single-mode structure
(IEEE, 2013) Del Villar, Ignacio; Socorro Leránoz, Abián Bentor; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
By coating a single-mode–multimode–single-mode (SMS) structure with a complex refractive index thin-film the central wavelength of the transmission and attenuation bands of the optical spectrum can be shifted. By adequate selection of multimode segment length and diameter, the thin-film thickness and the thin-film refractive index, the sensitivity of the device to the surrounding medium refractive index, the thickness of the thin-film or the refractive index of the thin-film can be optimized. Experimental results are corroborated numerically with the transfer matrix method.
Open Access
Lossy mode resonances dependence on the geometry of a tapered monomode optical fiber
(Elsevier, 2012) Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Open Access
Humidity sensor based on Bragg gratings developed on the end facet of an optical fiber by sputtering of one single material
(MDPI, 2017) Ascorbe Muruzabal, Joaquín; Corres Sanz, Jesús María; 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
The refractive index of sputtered indium oxide nanocoatings has been altered just by changing the sputtering parameters, such as pressure. These induced changes have been exploited for the generation of a grating on the end facet of an optical fiber towards the development of wavelength-modulated optical fiber humidity sensors. A theoretical analysis has also been performed in order to study the different parameters involved in the fabrication of this optical structure and how they would affect the sensitivity of these devices. Experimental and theoretical results are in good agreement. A sensitivity of 150 pm/%RH was obtained for relative humidity changes from 20% to 60%. This kind of humidity sensors shows a maximum hysteresis of 1.3% relative humidity.