Open Access
SnO2 based optical fiber refractometers
(SPIE, 2012) Sánchez Zábal, Pedro; Ruiz Zamarreño, Carlos; Hernáez Sáenz de Zaitigui, Miguel; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
In this work, the fabrication and characterization of refractometers based on lossy mode resonances (LMR) is presented. Tin dioxide (SnO2) films deposited on optical fibers are used as the LMR supporting coatings. These resonances shift to the red as a function of the external refractive index, enabling the fabrication of robust and highly reproducible wavelength-based optical fiber refractometers. The obtained SnO2-based refractometer shows an average sensitivity of 7198 nm/refractive index unit (RIU) in the range 1.333-1.420 RIU.
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
Nanodeposition of materials with complex refractive index in long period fiber gratings
(IEEE, 2005) Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Achaerandio Alvira, Miguel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
An overlay of higher refractive index than the cladding is deposited on a Long Period Fiber Grating (LPFG). This permits to improve in a great manner the sensitivity of the device to ambient and overlay refractive index changes. This causes large shifts of the attenuation bands in the transmission spectrum. To obtain a maximum sensitivity for specific refractive indices of the overlay and the ambient, an optimum overlay thickness must be selected. If the refractive index of the overlay is complex there is an additional phenomenon of vanishing of the attenuation bands in the transmission spectrum. This occurs for specific thickness values of the overlay. The problem is analyzed with a numerical method based on LP mode approximation and coupled mode theory. Experimental results are contrasted with theoretical ones
Open Access
Monitoring the etching process in LPFGs towards development of highly sensitive sensors
(MDPI, 2017) Del Villar, Ignacio; Cruz, José Luis; Socorro Leránoz, Abián Bentor; Díaz Lucas, Silvia; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa eta Elektronikoa; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería Eléctrica y Electrónica; Gobierno de Navarra / Nafarroako Gobernua: 2016/PI008; Gobierno de Navarra / Nafarroako Gobernua: 2016/PC025; Gobierno de Navarra / Nafarroako Gobernua: 2016/PC026
In this work, the monitoring of the etching process up to a diameter of 30 µm of two LPFG structures has been compared, one of them had initially 125 µm, whereas the second one had 80 µm. By tracking the wavelength shift of the resonance bands during the etching process it is possible to check the quality of etching process (the 80 µm fibre performs better than de 125 µm fibre), and to stop for a specific cladding mode coupling, which permits to obtain an improved sensitivity compared to the initial structure.
Open Access
Generation of lossy mode resonances with different nanocoatings deposited on coverslips
(Optical Society of America, 2020) Fuentes Lorenzo, Omar; Goicoechea Fernández, Javier; Corres Sanz, Jesús María; Del Villar, Ignacio; Ozcariz Celaya, Aritz; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The generation of lossy mode resonances (LMRs) with a setup based on lateral incidence of light in coverslips is a simple platform that can be used for sensing. Here the versatility of this platform is proved by studying the deposition of different coating materials. The devices were characterized with both SEM and AFM microscopy, as well as ellipsometry, which allowed obtaining the main parameters of the coatings (thickness, refractive index and extinction coefficient) and relating them with the different sensitivities to refractive index attained with each material. In this way it was possible to confirm and complete the basic rules observed with lossy mode resonance based optical fiber sensors towards the design of simpler and more compact applications in domains such as chemical sensors or biosensors.
Open Access
D-shape optical fiber refractometer based on TM and TE lossy mode resonances
(SPIE, 2014) Zubiate Orzanco, Pablo; Ruiz Zamarreño, Carlos; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza
The fabrication and characterization of an optical fiber refractometer based on Lossy Mode Resonances (LMR) is presented. TiO2/ poly (sodium 4-styrenesulfonate) coatings deposited on side-polished D-shaped optical fibers are used as LMR supporting coatings. LMRs are sensitive to the external medium refractive index and D-shaped optical fibers enable the observation of TE and TM LMR polarizations. These refractometers based on TE and TM LMR showed an average sensitivity of 2737 nm/RIU and 2893 nm/RIU respectively for a surrounding medium refractive index (SMRI) range from 1.35 to 1.41.
Open Access
Etched and nanocoated SMS fiber sensor for detection of salinity concentration
(MDPI, 2017) Cardona-Maya, Yamile; Del Villar, Ignacio; Socorro Leránoz, Abián Bentor; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Botero-Cadavid, Juan F.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua: 2016/PI008; Gobierno de Navarra / Nafarroako Gobernua: 2016/PC025; Gobierno de Navarra / Nafarroako Gobernua: 2016/PC026
An optical fibre refractometer has been developed by etching and deposition of a thin film of indium tin oxide (ITO) on a single-mode-multimode-single-mode (SMS) fibre structure. The interference between modes in this structure is sensitive to the refractive index changes of the surrounding medium, achieving sensitivities of up to 7000 nm/RIU in the 1.333–1.338 RIU range. A salinity sensor has been implemented as a practical application of this proposed structure. Fast Fourier transform (FFT) analysis and tracking of an interference dip were used to monitor the interference between modes obtaining sensitivities of 0.99 nm/PSU and 0.025 rad/PSU, respectively.
Open Access
Multimode – coreless – multimode fiber-based sensors: theoretical and experimental study
(IEEE, 2019) San Fabián García, Noé; Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Díaz Lucas, Silvia; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
This paper presents a complete study on the spectral behavior of a multimode-coreless-multimode fiber-optic structure, as well as its application as a refractometer and a liquid level sensor. The combination of two standard multimode fibers fused to a coreless fiber segment allows generating narrow interferometric bands in the optical spectrum, whose sensitivity can be improved by an adequate selection of the dimensions of the device (the coreless segment length and the diameter of the sensing area). A second way to improve the performance of the device is to deposit a thin film of SnO2, which allows increasing the sensitivity up to 314 nm/RIU. This widens the number of applications where this structure can be used. As an example, a liquid level sensor with 0.73 nm/mm sensitivity is presented.
Open Access
Optical fiber refractometers based on indium tin oxide coatings with response in the visible spectral region
(Elsevier, 2011) Ruiz Zamarreño, Carlos; López, S.; Hernáez Sáenz de Zaitigui, Miguel; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
This work presents the fabrication of optical fiber refractometers based on indium tin oxide (ITO) coatings with response in the visible spectral region. ITO thin-films have been sputtered by employing a rotating mechanism that enables the fabrication of smooth homogeneous coatings onto the optical fiber core. The ITO coated optical fiber devices present several resonances in the visible and infra-red region. These resonances show high optical power attenuations (more than 10 dB) in the visible spectral region, which produces changes in the colour of the output visible light. Therefore, since these resonances shift as a function of the surrounding medium refractive index (SMRI), it is feasible to determine the refractive index of the outer medium in contact with the ITO coating by simply monitoring the chromatic coordinates of the visible output light.
Open Access
Experimental study and sensing applications of polarization-dependent lossy mode resonances generated by D-shape coated optical fibers
(IEEE, 2015) Zubiate Orzanco, Pablo; Ruiz Zamarreño, Carlos; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The fabrication and characterization of an optical fiber refractometer based on Lossy Mode Resonances (LMR) is presented. TiO2/ poly (sodium 4-styrenesulfonate) (PSS) coatings deposited on side-polished D-shaped optical fibers are used as LMR supporting coatings. LMRs are sensitive to the external medium refractive index and D-shaped optical fibers enable the observation of TE and TM LMR polarizations. These refractometers based on TE and TM LMR showed an average sensitivity of 2737 nm/RIU and 2893 nm/RIU respectively for a surrounding medium refractive index (SMRI) range from 1.35 to 1.41. This work also explores the utilization of previously described refractometers in the context of two common industrial applications such as the determination of the sugar content or °Brix in beverages and the salt concentration in sea water.