Open Access
Planar-waveguide-lmr-based sensors: engineering the depth of characteristic curves
(IEEE, 2023) Shrivastav, Anand M.; Del Villar, Ignacio; Ascorbe Muruzabal, Joaquín; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Lossy mode resonance (LMR)-based sensors have been proven as one of the exponentially growing research fields since the last decade. These sensors have demonstrated their capabilities in the detection of several physical, chemical, and biological entities, such as refractive index, humidity, gases, enzymes, etc. Conventionally, LMR-based sensors are developed using optical fiber as the sensing platform, but to increase the broad range of applications and better tenability, planar waveguide substrates for LMR realization have been introduced in the last few years. This provides a greater degree of freedom for the sensor design such as tunability in substrate thickness, material, and better surface immobilization. The current study focuses on evaluating the effect of substrate thickness on LMR-based optical sensors to achieve higher sensing performance. For experiments, 150-μm-thick glass coverslips are used as the thin planer substrate, which is then coated with a few nanometers thick LMR-supported SnO 2 layer using the dc sputtering method. Furthermore, to monitor the effect of the changing substrate thickness, the width of the glass coverslip is reduced through the chemical etching process using the 40% HF solution, and simultaneously, the changes in LMR spectra are analyzed. The study shows that the depth of LMR curves strongly depend on the thickness of the waveguide providing LMRs with lower substrate thickness possesses higher depth. Greater depth in LMR curves is a crucial factor in identifying the minimum transmission wavelength of resonance, making it easier to track and detect the targeted parameter. This characteristic greatly enhances the applicability of LMR-based sensors in industrial applications.
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.
Embargo
Experimental study of sensing performance using hyperbolic mode resonances
(Elsevier, 2025-01-01) Matías Maestro, Ignacio; Del Villar, Ignacio; Corres Sanz, Jesús María; González Salgueiro, Lázaro José; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Surface plasmon resonance (SPR) and lossy mode resonance (LMR) are prominent sensing mechanisms utilized across various fields. The Kretschmann configuration is commonly employed for SPR, while LMR is favored in planar waveguides or optical fibers due to high incidence angles. Recently, hyperbolic mode resonance (HMR) has emerged as a hybrid approach, combining metallic and dielectric thin films. This study explores the impact of incidence angle on HMR using the Kretschmann configuration. Four samples with varying gold (Au) and tin dioxide (SnO2) layer thicknesses were fabricated and characterized using Atomic Force Microscopy (AFM). Experimental setups employed the Kretschmann configuration for reflectance spectrum analysis. Results indicate enhanced sensitivity and figure of merit (FoM) with an additional SnO2 layer compared to the case without SnO2. Particularly with a 36 nm Au thickness the sensitivity doubles and the FoM improves by 16 %. Numerical simulations validate these findings, confirming the optimized performance of HMR for specific layer thicknesses and incidence angles.
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
Generation of lossy mode resonances in planar waveguides toward development of humidity sensors
(IEEE, 2019) Fuentes Lorenzo, Omar; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Del Villar, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Lossy mode resonances (LMRs) are typically obtained with optical fibre. The Kretschmann configuration is an alternative but LMRs are generated with angles approaching grazing incidence. In this work, a new setup is explored, based on the lateral incidence of light on conventional planar waveguides such as glass slides or coverslips. Indium tin oxide was deposited onto both types of waveguides generating LMRs. The results of the simulations carried out agree well with the experimental results. As an example of the potential of this new and simple optical configuration, a humidity sensor with a sensitivity of 0.212 nm/% relative humidity (RH) in the range from 65% to 90% of RH was developed, which expedites the development of other types of sensors already explored with LMR-based optical fibre sensors.
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
Optical fiber vacuum sensor based on modal interferometer and PDMS coating
(IEEE, 2019) Ascorbe Muruzabal, Joaquín; Fuentes Lorenzo, Omar; 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
This work studies the behavior of polydimethylsiloxane (PDMS) as a transducer for optical vacuum pressure measurements. The optical structure chosen for this device is a modal interferometer achieved by splicing a coreless multimode optical fiber between two single mode fibers. Then, an etching process is applied to the obtained device, in order to decrease the diameter of the fiber and increase the sensitivity. Finally, the fiber is coated by dip-coating with a layer of PDMS, which changes its volume with pressure changes. The device has been studied in the 1x10(-3) mbar to 10 mbar range with a wavelength shift of 4 nm. A maximum sensitivity of 35 nm/mbar was obtained. The simple fabrication process, which can be applied to more sensitive structures, suggest that PDMS can be a good choice for the development of optical fiber vacuum sensors.
Open Access
Lossy mode resonances generated in planar configuration for two-parameter sensing
(IEEE, 2021-04-29) Fuentes Lorenzo, Omar; Corres Sanz, Jesús María; Domínguez Rodríguez, Ismel; Del Villar, Ignacio; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
This work shows a new sensor structure for simultaneous measurement of two parameters, temperature and refractive index. The optical configuration consists of incidence of light on the edge of a soda-lime coverslip fully coated with a CuO thin film and partially coated with a PDMS thick layer. This planar configuration permitted to generate two separated lossy mode resonances (LMRs): one centered at 600 nm and the other at 1000 nm. The second resonance is induced by the PDMS layer and it can be used to measure the temperature due to its high thermo-optic coefficient (the sensitivity is -1.75 nm/°C in the temperature range from 20 to 40 °C), whereas the first resonance is used for sensing refractive index with sensitivity of 1460 nm/RIU in the refractive index range from 1.3328 and 1.37. Finally, a calibration test was carried out using a calibrated oil series with refractive index ranging from 1.33 to 1.36. This work demonstrates the possibility of generating multiples resonances in a single structure as simple as a coverslip, which can be used as a multi-parameter interchangeable sensor, especially suitable for biological applications or the detection of heavy metals in water.
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.