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Ignacio Del Villar

Other affiliations: Universidad Pública de Navarra
Bio: Ignacio Del Villar is an academic researcher from University of Navarra. The author has contributed to research in topics: Optical fiber & Refractive index. The author has an hindex of 25, co-authored 100 publications receiving 2347 citations. Previous affiliations of Ignacio Del Villar include Universidad Pública de Navarra.


Papers
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Journal ArticleDOI
TL;DR: The deposition of an overlay of higher refractive index than the cladding in a Long Period Fiber Grating permits to improve the sensitivity to ambient refractiveIndex changes in a great manner, and henceforward fast shifts of the resonance wavelength of the attenuations bands in the transmission spectrum are studied.
Abstract: The deposition of an overlay of higher refractive index than the cladding in a Long Period Fiber Grating (LPFG) permits to improve the sensitivity to ambient refractive index changes in a great manner. When the overlay is thick enough, one of the cladding modes is guided by the overlay. This causes important shifts in the effective index values of the cladding modes, and henceforward fast shifts of the resonance wavelength of the attenuations bands in the transmission spectrum. This could be applied for improving the sensitivity of LPFG sensors. The problem is analysed with a numerical method based on LP mode approximation and coupled mode theory, which agrees with so far published experimental results.

357 citations

Journal ArticleDOI
TL;DR: Repeated experiments confirm a big leap in performance thanks to the capability to detect femtomolar concentrations in human serum, improving the detection limit by 3 orders of magnitude when compared with other fiber-based configurations.
Abstract: The advent of optical fiber-based biosensors combined with that of nanotechnologies has provided an opportunity for developing in situ, portable, lightweight, versatile, and high-performance optical sensing platforms. We report on the generation of lossy mode resonances by the deposition of nanometer-thick metal oxide films on optical fibers, which makes it possible to measure precisely and accurately the changes in optical properties of the fiber-surrounding medium with very high sensitivity compared to other technology platforms, such as long period gratings or surface plasmon resonances, the gold standard in label-free and real-time biomolecular interaction analysis. This property, combined with the application of specialty structures such as D-shaped fibers, permits enhancing the light–matter interaction. SEM and TEM imaging together with X-EDS tool have been utilized to characterize the two films used, i.e., indium tin oxide and tin dioxide. Moreover, the experimental transmission spectra obtained af...

172 citations

Journal ArticleDOI
TL;DR: Lossy mode resonances can be obtained in the transmission spectrum of cladding removed multimode optical fiber coated with a thin-film and basic rules of design, which enable the selection of the best parameters for each specific sensing application, are indicated in this work.
Abstract: 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. Some basic rules of design, which enable the selection of the best parameters for each specific sensing application, are indicated in this work.

168 citations

Journal ArticleDOI
TL;DR: Lossy-mode resonance (LMR)-based optical sensing technology has emerged in the last two decades as a nanotechnological platform with very interesting and promising properties as mentioned in this paper, which enables one to tune the position of the resonance in the optical spectrum, to excite the resonance with both transverse electric (TE) and transverse magnetic (TM) polarized light.
Abstract: Lossy-mode resonance (LMR)–based optical sensing technology has emerged in the last two decades as a nanotechnological platform with very interesting and promising properties. LMR complements the metallic materials typically used in surface plasmon resonance (SPR)–based sensors, with metallic oxides and polymers. In addition, it enables one to tune the position of the resonance in the optical spectrum, to excite the resonance with both transverse electric (TE) and transverse magnetic (TM) polarized light, and to generate multiple resonances. The domains of application are numerous: as sensors for detection of refractive indices voltage, pH, humidity, chemical species, and antigens, as well as biosensors. This review will discuss the bases of this relatively new technology and will show the main contributions that have permitted the optimization of its performance to the point that the question arises as to whether LMR–based optical sensors could become the sensing platform of the near future.

167 citations

Journal ArticleDOI
TL;DR: A theoretical model for analyzing a multilayer cylindrical waveguide is presented that permits the phenomenon to be understood and predicted and results are corroborated with experimental ones obtained by electrostatic self-assembly.
Abstract: It was proved that the deposition of an overlay material onto a long-period fiber grating causes important shifts in the wavelengths of the typical attenuation bands that are caused by coupling between cladding and core modes [Opt. Lett.27, 682 (2002) ]. A theoretical model for analyzing a multilayer cylindrical waveguide is presented that permits the phenomenon to be understood and predicted. An overlay of higher refractive index than the cladding starts to guide a mode if a certain thickness value is exceeded. This causes large shifts in the resonance wavelength induced by the grating. One important application of this phenomenon to sensors is enhancement of the sensitivity of a long-period fiber grating to ambient conditions. Theoretical results are corroborated with experimental ones obtained by electrostatic self-assembly.

123 citations


Cited by
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Book ChapterDOI
27 Jan 2010

878 citations

Journal ArticleDOI
TL;DR: The miniaturized fiber inline Fabry-Perot interferometer, with an open micro-notch cavity fabricated by one-step fs laser micromachining, is reported for highly sensitive refractive index measurement.
Abstract: We report a miniaturized fiber inline Fabry-Perot interferometer (FPI), with an open micro-notch cavity fabricated by one-step fs laser micromachining, for highly sensitive refractive index measurement. The device was tested for measurement of the refractive indices of various liquids including isopropanol, acetone and methanol at room temperature, as well as the temperature-dependent refractive index of deionized water from 3 to 90 degrees C. The sensitivity for measurement of refractive index change of water was 1163 nm/RIU at the wavelength of 1550 nm. The temperature cross-sensitivity of the device was about 1.1x10(-6) RIU/degrees C. The small size, all-fiber structure, small temperature dependence, linear response and high sensitivity, make the device attractive for chemical and biological sensing.

395 citations

Journal ArticleDOI
TL;DR: In this paper, the fundamental concepts involved in various sensing approaches, and the differentiators which have led to commercial impact are discussed, as well as the future of fiber-optic sensors.
Abstract: Sensing via fiber optics has occupied R&D groups for over 40 years, and some important transitions into the commercial sector have been achieved. We look at the fundamental concepts involved in the various sensing approaches, and the differentiators which have led to commercial impact. We also look to the future of fiber-optic sensors.

372 citations

Journal ArticleDOI
TL;DR: The deposition of an overlay of higher refractive index than the cladding in a Long Period Fiber Grating permits to improve the sensitivity to ambient refractiveIndex changes in a great manner, and henceforward fast shifts of the resonance wavelength of the attenuations bands in the transmission spectrum are studied.
Abstract: The deposition of an overlay of higher refractive index than the cladding in a Long Period Fiber Grating (LPFG) permits to improve the sensitivity to ambient refractive index changes in a great manner. When the overlay is thick enough, one of the cladding modes is guided by the overlay. This causes important shifts in the effective index values of the cladding modes, and henceforward fast shifts of the resonance wavelength of the attenuations bands in the transmission spectrum. This could be applied for improving the sensitivity of LPFG sensors. The problem is analysed with a numerical method based on LP mode approximation and coupled mode theory, which agrees with so far published experimental results.

357 citations

Journal ArticleDOI
04 Jun 2007-Sensors
TL;DR: In this paper, the authors present a review of optical fiber biosensors in the last decade and discuss the trends in optical fiber sensor applications in real samples and discuss their applications in various analytical fields.
Abstract: Remarkable developments can be seen in the field of optical fibre biosensors in the last decade. More sensors for specific analytes have been reported, novel sensing chemistries or transduction principles have been introduced, and applications in various analytical fields have been realised. This review consists of papers mainly reported in the last decade and presents about applications of optical fiber biosensors. Discussions on the trends in optical fiber biosensor applications in real samples are enumerated.

277 citations