Open Access
High sensitivity lossy-mode resonance refractometer using low refractive index PFA planar waveguide
(Elsevier, 2023) Domínguez Rodríguez, Ismel; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Ascorbe Muruzabal, Joaquín; Del Villar, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work a new strategy to improve the sensitivity of refractometers based on lossy-mode resonances has been proved. The proximity of the PFA (tetrafluoroethylene-perfluoro polymer) substrate refractive index to that of water has permitted to implement an optical refractometer with a sensitivity of 41,034 nm per refractive index unit (nm/RIU) for refractive indices ranging from 1.3318 to 1.3347. The work is supported with both theoretical and experimental results. This high sensitivity can be used for the development of LMR based chemical sensors and biosensors, where a low limit of detection is required, with the additional advantage of a simple disposable planar configuration.
Open Access
Increasing the sensitivity of an optic level sensor with a wavelength and phase sensitive single-mode multimode single-mode (SMS) fiber structure
(IEEE, 2017) Fuentes Lorenzo, Omar; Del Villar, Ignacio; Vento Álvarez, José Raúl; Socorro Leránoz, Abián Bentor; Gallego Martínez, Elieser Ernesto; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
The sensitivity of a liquid level sensor based on a single-mode-multimode-single-mode fiber structure has been increased by hydrofluoric acid etching. The etching process was analyzed and monitored both theoretical and experimentally, which permitted to observe that a sinusoidal spectrum can be obtained for low diameters. As an example, a 2.77 fold sensitivity increase was attained by etching from diameter 125 to 50 μm. Moreover, the sinusoidal shape of the optical spectrum permitted to monitor liquid level changes both in wavelength and phase. The cross sensitivity of the sensor to refractive index and temperature was also studied.
Open Access
Fiber optic ammonia sensor using Bromocresol Green pH indicator
(IEEE, 2014-12-15) Rodríguez Rodríguez, Adolfo Josué; May Arrioja, Daniel A.; Domínguez Cruz, René; Ruiz Zamarreño, Carlos; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We report a fiber optic sensor for low levels of ammonia gas detection based on the use a Bromocresol Green (BCG) pH indicator attached to the optical fiber employing hydrophobic and gas permeable polyurethane film named Tecoflex® as attraping matrix. Highly reproducible and reversible fiber optical sensors have been achieved employing simple and short fabrication processes. The advantage for employ a BCG pH indicator is to take advantage of the basicity of ammonia exhibiting a wide spectral response (500 nm-750 nm) and shows recovery times of less than 15 s. The Tecoflex® film provides additional advantages to be measured to the sensitive area of the sensor, such as operation even in extremely dry environments, efficient transport and prevent leakage or detachment of the BCG pH indicator. The combination of the BCG pH indicator and Tecoflex® film provides a reliable and robust fiber optic ammonia gas sensor.
Open Access
Strategies for fabrication of hydrogen peroxide sensors based on electrostatic self-assembly (ESA) method
(Elsevier, 2004) Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Echeverría Morrás, Jesús; Claus, Richard O.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
An optical fiber sensor has been fabricated for detection of 5 M–0.1mM concentrations of hydrogen peroxide with a linear response. The deposition method used is electrostatic self-assembly (ESA) of polymer cationic and anionic layers. Prussian Blue (PB) has been included in the polycation layers. The optical fiber sensor is included in a reflection setup, where the measuring technique is based on the slope of the optical reflected power change caused by oxidation of Prussian White (PW) to Prussian Blue. The sensor recovers after immersion in a reductive agent and is immune against a variety of components. Measurement of hydrogen peroxide has been proved successfully in a wide range pHs between 3 and 9. Some techniques have been applied in order to avoid the lost of indicator.
Open Access
Beyond near-infrared lossy mode resonances with fluoride glass optical fiber
(Optica, 2021) Vitoria Pascual, Ignacio; Ruiz Zamarreño, Carlos; Ozcariz Celaya, Aritz; Imas González, José Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The objective of this Letter consists of the exploration of the lossy mode resonance (LMR) phenomenon beyond the nearinfrared region and specifically in the short wave infrared region (SWIR) and medium wave infrared region (MWIR). The experimental and theoretical results show for the first time, to the best of our knowledge, not only LMRs in these regions, but also the utilization of fluoride glass optical fiber associated with this phenomenon. The fabricated devices consist of a nanometric thin-film of titanium dioxide used as LMR generating material, which probed extraordinary sensitivities to external refractive index (RI) variations. RI sensitivity was studied in the SWIR and MWIR under different conditions, such as the LMR wavelength range or the order of resonance, showing a tremendous potential for the detection of minute concentrations of gaseous or biological compounds in different media.
Open Access
High sensitivity optical fiber pH sensor using poly(acrylic acid) nanofibers
(IEEE, 2013-12-19) Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Rodríguez García, Yoany; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work a new optical fiber pH sensor based on the deposition of poly(acrylic acid) (PAA) using the electrospinning technique is presented. The optical fiber structure consists of a 4 cm segment of hollow core fiber (50/150¿m) spliced between two standard multimode fibers onto which the nanoweb is deposited. The sensitive layer is a membrane composed by PAA nanofibers deposited onto the surface of an optical fiber. The sensor has a repetitive behavior and low hysteresis in the pH range 4-7, with an average sensitivity of 0,53 dB/pH.
Open Access
Humidity sensor based on a long-period fiber grating coated with a hydrophobic thin film
(2010) Urrutia Azcona, Aitor; Rivero Fuente, Pedro J.; Goicoechea Fernández, Javier; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
In this work it is proposed a novel fiber optic humidity sensor based on a functionally coated long-period fiber grating (LPG). The coating is composed of tetraorthosilicate matrix functionalized with perfluorooctyltriethoxysilane and its fabrication was performed by the sol-gel technique using a dip coating process using the LPG as substrate. This technique allows to fabricate sensitive films in a fast and simple way compared to other overlay fabrication techniques. The fabricated sensor was tested in a programmable temperature and climatic chamber. Relative humidity (RH) was varied in range from 20%RH to 80%RH at room temperature. The results showed a smooth exponential-like wavelength shift of the LPG attenuation band.
Open Access
Sensitivity enhancement by diameter reduction in low cutoff wavelength single-mode multimode singlemode (SMS) fiber sensors
(IEEE, 2017) Goñi Carnicero, Jaime; Del Villar, Ignacio; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Two different low cutoff wavelength single-mode fibers were used in single-mode multimode single-mode (SMS) configuration with the aim of designing sensors operating at short wavelengths, where optical sources and spectrometers are less expensive than in telecommunications bands. The diameter of the SMS structure was reduced with an etching process based on hydrofluoric acid immersion. The results prove that the devices can operate at wavelength ranges from 600 to 1200 nm and that multiple peaks can be obtained, each one with a different sensitivity that is proportional to the wavelength. Moreover, a fivefold increase in sensitivity to refractive index can be obtained. This high sensitivity indicates the possibility to apply this simple and cost-effective device in other applications such as biosensors or chemical sensors.
Open Access
Tunable electro-optic wavelength filter based on lossy-guided mode resonances
(Optical Society of America, 2013) Corres Sanz, Jesús María; Ascorbe Muruzabal, Joaquín; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work an optical fiber tunable filter based on lossy guided-mode resonances (LGMR) is proposed. It consists of a multilayer structure deposited onto the surface of a plastic cladding removed multimode fiber. The first layer is used to generate the LGMR and to work as the first electrode as well; the second one to tune the filter and the outer layer forms the other electrode. The fabricated filter has demonstrated a good sensitivity to the applied voltage showing a change of the LGMR wavelength of 0.4 nm/V. Among other applications, this filter is intended to be used as electro-optic wavelength filter or modulator.
Open Access
Analysis of one-dimensional photonic band gap structures with a liquid crystal defect towards development of fiber-optic tunable wavelength filters
(Optical Society of America, 2003) Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Claus, Richard O.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
A theoretical analysis of a fiber optical photonic band gap based tunable wavelength filter is presented. The design presented here is based on the quarter wave reflector with a liquid crystal defect layer in the middle of the structure. The filter generated by the structure is shifted in wavelength as the voltage applied to the structure is modified. Some critical parameters are analyzed: the effect of the consideration of fiber as the first layer and not the input medium in the shape of the filter, the number of layers of the structure, and the thickness of the defect layer. This last parameter determines the width of the wavelength sweep of the filter, but is limited by the creation of more defects. Some rules of practical implementation of this device are also given.