Elosua Cesar

• PhD
• Research Associate at Public University of Navarre

This work exemplifies how incorporating organosilane modifiers into silica matrices allows for tuning the optical response of reflection photonic sensors through customizing the textural properties of hybrid xerogel sensing films. Xerogels with propyl molar percentages 0, 5, and 10% are used to construct photonic probes (OFS0pTEOS, OFS5pTEOS and OF...

The incorporation of organic groups into sol-gel silica materials is known to have a noticeable impact on the properties and structure of the resulting xerogels due to the combination of the properties inherent to the organic fragments (functionality and flexibility) with the mechanical and structural stability of the inorganic matrix. However, the...

Citation: Elisa, M.; Sava, B.A.; Eftimie, M.; Nicoara, A.I.; Vasiliu, I.C.; Rusu, M.I.; Bartha, C.; Enculescu, M.; Kuncser, A.C.; Oane, M.; et al. A Nanocomposite Sol-Gel Film Based on PbS Quantum Dots Embedded into an Amorphous Host Inorganic Matrix. Materials 2023, 16, 7105. Abstract: In this study, a sol-gel film based on lead sulfide (PbS) quan...

We present a zinc oxide (ZnO) out-cladding, overlaid optical fiber Bragg grating sensor, for the detection of vapors of common alcohols and acetone at concentrations lower than 25 ppm while operating at room temperature (RT). The optical fiber sensing results indicate a chemostriction effect occurring in the ZnO layer when exposed to volatile organ...

IV-VI semiconductor quantum dots embedded into an inorganic matrix represent nanostructured composite materials with potential application in temperature sensor systems. This study explores the optical, structural, and morphological properties of a novel PbS quantum dots (QDs)-doped inorganic thin film belonging to the Al2O3-SiO2-P2O5 system. The f...

The idea of utilizing game elements in non-gaming situations has sparked a lot of attention in recent years, especially in topics such as education and training. Game-based techniques appear to be an increasing trend in a wide range of learning areas, including health, social policy, and engineering, among others, not only in primary school but als...

There exists an increasing interest in monitoring low concentrations of biochemical species, as they allow the early-stage detection of illnesses or the monitoring of the environment quality. Thus, both companies and research groups are focused on the development of accurate, fast and highly sensitive biosensors. Optical fiber sensors have been wid...

Eu, Er, Yb-Er, and Dy-doped phosphate glasses were prepared by a wet-route processing of chemical precursors followed by melt-quenching and annealing. XRD measurements highlighted the amorphous nature of the investigated glasses. UV-Vis absorption spectra revealed peaks specific to f-f electronic transitions of the doping ions whereas FTIR and Rama...

This chapter lists the advantages of using optical fibre as technology for gas or volatile organic compounds (VOC) sensing, emphasizing the possibility of multiplexing. It describes sensing materials used to develop optical fibre sensors (OFSs) with the aim of detecting gases and VOCs. The chapter explains the different mechanisms of transduction o...

A simple method to prepare a nano pattern along the surface of an optical fiber is applied in this Letter to develop a pH sensor. The template is made of a block copolymer that defines specific locations where gold nano particles are adsorbed on forming clusters. The average diameter of the resulting agglomerates is 121 nm, and the mean distance be...

Introduction Gold nanoparticles (Au NP) exhibit interesting optical, physical and chemical features that can be tuned by modifying their morphology or by functionalizing them [1]. Therefore, a wide variety of sensing applications based on optical fiber have been developed using them, such as the colorimetric detection of toxic metal ions, cysteine...

Since the first publications related to microstructured optical fibers (MOFs), the development of optical fiber sensors (OFS) based on them has attracted the interest of many research groups because of the market niches that can take advantage of their specific features. Due to their unique structure based on a certain distribution of air holes, MO...

A fluorescent optical fiber sensor for the detection of mercury (Hg2+) ions in aqueous solutions is presented in this work. The sensor was based on a fluorophore-labeled thymine (T)-rich oligodeoxyribonucleotide (ON) sequence that was directly immobilized onto the tip of a tapered optical fiber. In the presence of mercury ions, the formation of T–H...

In this paper, the influence of the thickness of metallic-oxide coatings, ITO and SnO 2, on the sensitivity of a Microstructured Optical Fiber (MOF) Fabry-Pérot (FP) has been studied with the aim of developing ammonia gas fiber optic sensors. Also, the distribution of the optical power that can be coupled to the metallic-oxide sensing films is inve...

Due to the risks that water contamination implies for human health and environmental protection, monitoring the quality of water is a major concern of the present era. Therefore, in recent years several efforts have been dedicated to the development of fast, sensitive, and selective sensors for the detection of heavy metal ions. In particular, fluo...

A discrete sensor based on a SnO2-FP (Fabry-Pérot) cavity is presented and characterized in real soil conditions. Results are compared, for the first time to our knowledge, with a commercial capacitive sensor and gravimetric measurements.

Soil moisture content has always been an important parameter to control because it is a deterministic factor for site-specific irrigation, seeding, transplanting, and compaction detection. In this work, a discrete sensor that is based on a SnO2–FP (Fabry-Pérot) cavity is presented and characterized in real soil conditions. As far as authors know, i...

In this paper, different core structures of microstructured optical fibers (MOFs) for low-finesse Fabry–Pérot (FP) sensors are experimentally compared to get the highest sensitivity. These devices are designed for volatile organic compounds (VOCs) measurements. Indium tin oxide (ITO) thin films were deposited by sputtering on the MOFs and different...

In this paper, a multiplexing system for simultaneous interrogation of optical fiber sensors which measure different parameters is presented and validated. The whole system has been tested with 6 different sensing heads with different purposes: one temperature sensing head, two relative humidity sensors and three VOCs leak sensors; all of them base...

In this paper, a new optical fiber sensor for relative humidity measurements is presented and characterized. The sensor is based on a SnO2 sputtering deposition on a microstructured optical fiber (MOF) low-finesse Fabry-Pérot (FP) sensing head. The feasibility of the device as a breathing sensor is also experimentally demonstrated. The interrogatio...

Luminescence-based sensing applications range from agriculture to biology, including medicine and environmental care, which indicates the importance of this technique as a detection tool. Luminescent optical sensors are required to be highly stable, sensitive, and selective, three crucial features that can be achieved by fabricating them by means o...

The measurement of chemical and biomedical parameters can take advantage of the features exclusively offered by optical fibre: passive nature, electromagnetic immunity and chemical stability are some of the most relevant ones. The small dimensions of the fibre generally require that the sensing material be loaded into a supporting matrix whose morp...

An optical fiber sensor for ethanol detection in exhaled breath has been developed. It has been fabricated by functionalizing a Long Period Grating with a metal-organic framework, ZIF-8. The sensor’s response was tested by exposure to exhaled breath of a person before and after the ingestion of alcoholic drinks, showing a higher wavelength differen...

In this paper, we experimentally compare several core structures of Microstructured Optical Fibers (MOFs) for low-finesse Fabry-Pérot (FP) sensors. These sensors are designed for Volatile Organic Compounds (VOCs) measurements. We deposit Indium Tin Oxide (ITO) thin films by sputtering on the MOFs and different optical phase responses of the FP were...

In order to improve the sensitivity of an interferometric humidity sensor based on a photonic crystal fiber with a sputtered SnO2 nanocoating, a study of the effect of its thickness on the sensitivity is presented in this paper. Sensors with coatings of different thickness were performed by applying distinct sputtering times in order to obtain an o...

In this work, different luminescence-based optical fiber oxygen sensors have been fabricated by means of the Layer-by-Layer nanoassembly technique. The sensing material employed has been a platinum metalloporphyrin, platinum tetrakis pentafluorophenylporphine (Pt-TFFP), which has been entrapped into anionic micelles. Poly(diallyldimethylammonium ch...

In this paper, an optical fiber interferometric humidity sensor is presented. The device consists of 1 cm-long segment of photonic crystal fiber (PCF) spliced to standard single mode fibers (SMFs), forming aninterferometer: the two collapsed interfaces between PCF and SMF segments produce the excitation andrecombination of core and cladding modes....

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...

In this work, a comparative study of luminescent optical fiber oxygen sensors fabricated by means of Layer-by-Layer nanoassembly technique (LbL) has been carried out. The oxygen-sensitive fluorophore is the same in all the cases, the metalloporphyrin platinum tetrakis pentafluorophenylporphin (Pt-TFPP), which was deposited using LbL method by entra...

A method is proposed to determine lifetime of luminescent emissions based on the phase shift measurement employing the digitalized Lissajous representation: this diagram has been typically used with analogical algorithms, whereas the proposed method is performed in digital domain, showing an improved accuracy and repeatability. The procedure is stu...

In this paper, a new sensor system for relative humidity measurements based on a SnO2 sputtering deposition on a microstructured optical fiber (MOF) low-finesse Fabry-Perot (FP) sensing head is presented and characterized. The interrogation of the sensing head is carried out by monitoring the Fast Fourier Transform phase variations of the FP interf...

An optrode able to detect glucose dissolved in water has been implemented. The device is based on the luminescence emission of a Molecularly Imprinted Polymer synthesized specifically for glucose detection, therefore its intensity changes in presence of glucose. This sensing material is attached onto a cleaved ended polymer-clad optical fibre and i...

Nanometer scale coatings with a complex refractive index deposited on optical fibre permit to obtain attenuation bands in the transmission spectrum, whose central wavelength coincides with the moment when a mode guided in the optical fibre cladding starts to be guided in the coating. Due to the complex refractive index of the coating, the guided mo...

Fiber optic sensors have been developed taking advantage on the synergy between the properties of nanostructured materials and the ones that characterize an optical fiber. The mechanical properties of optical fiber introduce some restrictions to the techniques used for the deposition of materials. As an alternative to the classical deposition proce...

An optical fiber sensor to measure gaseous oxygen is presented in this work. The device is based on platinum tetrakis pentrafluorophenyporphine (PtTFPP), a reagent that shows a luminescence at 650 nm when it is illuminated at 390 nm. The emitted signal decreases as oxygen concentrations increases. This sensing material is deposited onto a cleaved-e...

A sensor based on luminescence has been prepared depositing the luminescent complex platinum tetrakis pentrafluorophenyporphine (PtTFPP) onto a plastic-clad silica (PCS) optical fiber. The sensing film is constructed in terms of Layer-by-Layer method. A LED centered at 400 nm was used to interrogate the sensor in a reflection configuration, registe...

In the last 4 years, experimental evidences about the potential use of optical sensors based on Lossy Mode Resonances (LMR) have been presented in the literature. These LMR sensors have some similarities with Surface Plasmon Resonance (SPR) sensors, the gold standard in label-free, real-time biomolecular interaction analysis. In these new LMR senso...

Multimode interference (MMI) devices have demonstrated to be simple and inexpensive fiber based photonic devices. This paper reviews the application of MMI devices to develop a variety of fiber sensors and tunable lasers.

Purpose: 90Y-microspheres are widely used for the radioembolization of metastatic liver cancer or hepatocellular carcinoma and there is a growing interest for imaging 90Y-microspheres with PET. The aim of this study is to evaluate the performance of a current generation PET/CT scanner for 90Y imaging and to optimize the PET protocol to improve the...

We propose a novel multifrequency phase-modulation method for luminescence spectroscopy using a rectangular-wave modulated excitation source with a short duty cycle. It is used for obtaining more detailed information about the luminescence system: the information provided by different harmonics allows estimating a model for describing the global fr...

An inorganic short chain polymer, poly(sodium phosphate), PSP, together with poly(allylamine hydrochloride), PAH, is used to fabricate layer-by-layer (LbL) films. The thickness, roughness, contact angle, and optical transmittance of these films are studied depending on three parameters: the precursor solution concentrations (10-3 and 10-4 M), the n...

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 The resonances appear in the visible region of the spectrum filtering specific wavelengths while the resonances shift to the red as a fun...

The particular behavior of poly(sodium phosphate) (PSP) when it is deposited by means of the spraying layer-by-layer (LbL) technique has been used here to enhance the response of optical fiber humidity sensors. The roughness of the PSP films varies depending on the concentration of the polymeric solutions. In this work, it is demonstrated that this...

A transmission sensor able to detect Volatile Organic Compounds (VOCs) has been developed using optical fiber with Plastic Cladding (PCS). Specifically, 1.5 cm of the cladding was removed in order to deposit an organometallic compound whose chemical structure is [Au2Ag2(C6F5)(4)(C6H5C CC6H5)(2)](n) along this section. This complex reacts reversely...

Four optical fiber sensors have been grouped in an array which is able to distinguish odors of different drinks. The sensing materials employed have been deposited onto optical fibers following the electrostatic self assembly method. The responses have been characterized in terms of reflected optical power; more specifically, the dynamic range and...

A novel optical fibre probe based on a tridentate bis(phosphinic amide)-phosphine oxide PhPO(C6H4POPhN(CH(CH3)2)2)2 (ligand 1) has been developed for the detection of europium(III) ions in water. The dip coating technique was used to deposit the ligand 1 encapsulated on a poly(vinyl chloride) membrane onto an optical fibre. The optimum deposition t...

An optical fiber sensor to monitor volatile organic compounds (VOCs) has been developed. The sensing material used is the organometallic [Au2Ag2(C6F5)4(NH3)2]n: its optical properties show reversible changes in presence of organic vapors. The main idea consists of using the sensing features of this material to prepare a sensor based on wavelength m...

Export Date: 20 July 2012, Source: Scopus, Art. No.: 5737748, doi: 10.1109/JSEN.2011.2131128, Language of Original Document: English, Correspondence Address: Fernandez-Vallejo, M.; Department of Electrical and Electronic Engineering, Public University of Navarra, Pamplona, Navarra 31006, Spain; email: montserrat.fernandez@unavarra.es, References: L...

The construction of single mode optical fibre (SMF) sensors to handle with volatile organic compounds (VOCs), has been optimized to operate at the third telecommunication window (1550nm). The main motivation is to take advantage of the photonic devices used in telecommunication systems that makes easier sensors multiplexing. Moreover, the low trans...

An experimental comparison of the stability performance of two different optical multiwavelength lasers is shown based on erbium highly doped fiber amplification. The two laser structures compared were: a star configuration using a 2x4 coupler to extract the signal from the ring to 4 FBGs and a structure with 4 active ring resonators that use both...

Health issues, such as Sick Building Syndrome (SBS), are being taken into account in new constructions, houses and several non industrial environments. SBS produces several manifestations, for example, respiratory irritative symptoms, headache and fatigue. It is caused by several factors. Most of them are related with the air quality, and the prese...

We propose a novel concept for hybrid networks that combine point and distributed Brillouin sensors in a cost-effective architecture that also deploys remote distributed Raman amplification to extend the sensing range. A 46-km proof-of-concept network is experimentally demonstrated integrating point vibration sensors based on fiber Bragg gratings a...

We propose a hybrid network that combine point and distributed Brillouin sensors in an architecture that also deploys remote distributed Raman amplification to extend the sensing range. A 46-km proof-of-concept network is experimentally demonstrated integrating point vibration sensors based on fiber-optic tapers, with distributed temperature sensin...

This paper presents the application of a new erbium-doped fiber ring laser configuration for the multiplexing of intensity sensors. The proposed scheme exploits two separated branches to generate simultaneous emission at four different wavelengths. Fiber Bragg gratings are used to select the operating wavelengths within the erbium-doped fiber ring....

In this work, a novel CWDM (Coarse Wavelength Division Multiplexing) network that multiplexes intensity modulated optical fibre sensors is presented. These transducers are based on a sensing material that suffers reversible changes in its optical properties in presence of organic vapours. This compound is fixed onto cleaved ended single mode optica...

An optical fiber sensor to detect volatile organic compounds (VOCs) is presented in this work. A material that shows a color change (from orange to green) in presence of organic vapors, is fixed onto a cleaved ended pigtail by electrostatic self assembly method. This way, when an optical signal is guided to the device head, changes in the sensing m...

A layer-by-layer assembly technique is used to coat layers of nano-thin-films of pH indicator on a U-bend optical fibre to create an effective sensor, using neutral red as the active element. The experimental results characterizing such a pH sensor shows a wide pH sensing range (from pH5 to pH10) fast response.

In this paper, a ring laser configuration for fibre sensing applications based on highly erbium-doped fibres is studied. The proposed configuration uses fibre Bragg grating reflectors in order to select the emission wavelengths. The experimental results have demonstrated that the topology arranged in a hybrid serial-tree configuration offers excell...

In this paper, we report the experimental demonstration of an amplified optical fiber double-ring network for the multiplexing of sensors. The network is designed to be inherently resilient to fiber failures because it enables simultaneous interrogation of all the optical fiber sensors using both rings. We demonstrate the feasibility of so-called "...

A family of vapochromic complexes has been used to develop optical fiber sensor transducers; these materials show reversible changes in their optical properties in presence of some solvents, so they can be used to detect volatile organic compounds (VOCs). The materials’ common chemical structure is described by the formula [Au2Ag2(C6F5)4L2]n, where...

A new amplified CWDM (coarse wavelength division multiplexing) self-referencing sensor network using phase-shifted fibre Bragg gratings (PS-FBGs) is experimentally demonstrated in this work. The network uses the PS-FBGs to address intensity sensors in a transmissive configuration, obtaining simultaneously in reflection a wavelength encoded referenc...

An optical fibre sensing element for detecting methanol and ethanol in the vapour phase was constructed based on an organometallic compound with the empirical formula [Au2Ag2(C6F5)4(C10H14)]n. This compound was fixed to a microporous xerogel support, which was synthesized using the sol–gel technique. The optical fibre device was designed to operate...

A novel vapochromic complex has been used to develop an optical fiber device sensitive to pyridine vapors. In solid state, this material is blue, and in the presence of pyridine vapors, its color changes to pink-white. The vapochromic material is solved in tetrahydrofuran (THF) and immobilized in a plasticized polymeric, fixing it onto a cleaved en...

A new amplified CWDM (Coarse Wavelength Division Multiplexing) self-referencing sensor network using phase-shifted fiber Bragg gratings (PS-FBGs) is experimentally demonstrated in this work. The network uses the PS-FBGs to address intensity sensors in a transmissive configuration, obtaining simultaneously in reflection a wavelength encoded referenc...

An optical fibre sensor has been implemented towards pyridine vapors detection;to achieve this, a novel vapochromic material has been used, which, in solid state, suffers achange in colour from blue to pink-white in presence of pyridine vapours. This complex isadded to a solution of PVC (Poly Vinyl Chloride), TBP (Tributylphosphate) andtetrahydrofu...

Sensors and Actuators B: Chemical j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s n b Optical fibre sensing element based on xerogel-supported [Au 2 Ag 2 (C 6 F 5) 4 (C 14 H 10)] n for the detection of methanol and ethanol in the vapour phase a b s t r a c t An optical fibre sensing element for detecting methanol a...

An optical fibre sensor for detection of volatile organic compounds (VOCs) has been implemented. This device is based on a vapochromic material presented in the form of bright red powders, which suffers reversible changes in its optical properties when exposed to some organic vapours. The sensor head consists of a nano interferometer doped with the...

Two different kinds of sensors have been developed by using the same kind of vapochromic complexes. The vapochromic materials [Au 2 Ag 2 (C 6 F 5) 4 L 2 ] n have different colours depending on the ligand L. These materials change, reversibly, their optical properties, colour and fluorescence, in the presence of the vapours of volatile organic compo...

Volatile organic compound (VOC) detection is a topic of growing interest withapplications in diverse fields, ranging from environmental uses to the food or chemicalindustries. Optical fiber VOC sensors offering new and interesting properties whichovercame some of the inconveniences found on traditional gas sensors appeared over twodecades ago. Than...

A fiber optic sensor for Volatile Organic Compounds (VOCs) detection has beendeveloped and characterized for some organic gasses. The sensor is based on a novelvapochromic material, which is able to change its optical properties in presence of organicvapors in a reversely way. A nano Fabry Perot is constructed onto a cleaved ended opticalfiber pigt...

A fibre optic sensor for detection of some volatile organic compounds (VOCs) is presented. This device is based on a new vapochromic material of formula [Au2Ag2(C6F5)4(C6H5N)2], presented in the form of bright red powders. This material changes its optical properties as colour or refractive index when exposed to some organic vapours, recovering its...

We describe a new gold-silver complex based on 2,2-bipyridine, whose formula is Au 2 Ag 2 C 6 F 5 4 C 5 H 4 N-C 5 H 4 N 2 n , used to detect volatile organic compounds VOCs such as ethanol, methanol, and acetic acid. This organometallic material is presented in the form of bright yellow powder, and suffers a change in its optical properties when it...

A new vapochromic material based on a gold–silver complex and diphenylacetyl, of formula [Au 2 Ag 2 (C 6 F 5) 4 (C 6 H 5 C≡CC 6 H 5)], has been developed and used for the detection of some volatile organic compounds (VOCs). The material is presented in the form of dark green powders. When the powders are in presence of VOC, its colour changes, yiel...