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Development of optical sensors for early stage diagnosis of pathologies. Fourth Network-wide Gla CER Co workshop Rennes - October 22 nd – 23 rd , 2014. Yaroslav Shpotyuk. CNRS, Glasses and Ceramics Team, University of Rennes 1. Outline. Introduction Description of work Results
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Development of optical sensors for early stage diagnosis of pathologies Fourth Network-wide GlaCERCo workshop Rennes - October 22nd – 23rd, 2014 YaroslavShpotyuk CNRS, Glasses and Ceramics Team, University of Rennes 1 Fourth Network-wide GlaCERCo workshop Rennes –October 22nd – 23rd, 2014
Outline • Introduction • Description of work • Results • Conclusions Fourth Network-wide GlaCERCo workshop Rennes –October 22nd – 23rd, 2014
Introduction (I)Research and training activities Role in GlaCERco Project:ESR 9 Start date : 01 October 2012 End date: 31 March 2014 WorkPackage 3. Design, synthesis and characterisation of specialglassessuitable forphotonic devices. Secondment: Phosphate glasses doped with a rare-earth for medical applications Start date :October, 2013 Duration: 2 months
Introduction (I)Objectives: CNRS • WorkPackage 3. Design, synthesis and characterisation of special glasses suitableforphotonicdevices. • Topic:Optical sensor characterization. • Main Objectives: • to fabricate Se\Te-based glasses with extended optical windows towards far IR, which allows detect new vibration modes of targeted molecules as signatures of early stage pathologies; • to develop rare-earth doped optical fibres pumped in visible or NIR and re-emitted in mid-IR as secondary remote sources for probing some biological liquids or tissues; • Investigate the stability of this glasses against environment (oxidation etc.) and physical ageing; • Improve the process of purification to avoid absorption in IR • caused by H2O, CO2, O-based bonds, etc.
Introduction (I)Objectives: Abo Academy • Preparation of rare-earth doped glasses of B2O3-CaO/SrO-P2O5 systems using different CaO/SrO ratios. • Investigation of the effect of the glass composition on the structural, optical and thermal properties of the glasses as well as on the glass bioactivity response when in contact with simulated body fluid (SBF). • Preparation of preforms with good quality for further fiber drawing. • Investigation of the effect of the drawing on the structural, optical and thermal properties of the glasses as well as on the glass bioactivity response when in contact with SBF.
Introduction (I)Still looking for Postdoc position… Joint-supervision PhD defense: 08.10.2014 Topic: Radiation induced effects on optical properties of As-Sb-S glasses. Faculty of Electronics Ivan Franko National University of Lviv Supervisor: IhorPolovynko Topic: Development of optical sensors for early diagnosis of pathologies. Institute of Chemistry University of Rennes 1, CNRS Supervisors: Bruno Bureau and Catherine Boussard-Pledel Fourth Network-wide GlaCERCo workshop Rennes –October 22nd – 23rd, 2014
Outline • Introduction • Description of work • Results • Conclusions Fourth Network-wide GlaCERCo workshop Rennes –October 22nd – 23rd, 2014
Description of workThe field of research Chalcogenide glass (ChG) – is a glass containing one or more chalcogen elements (S, Se or Te) with other elements from IV-th and V-th groups of the Periodic Table (typically As, Sb, Bi, Ge, etc.) obtained by conventional melt quenching. • ChG– the unique disordered solids, being simultaneously: • inorganic polymers, in terms of their chemical nature, • semiconductors,in terms their electronic nature, • glasses,in terms of their thermodynamic nature.
Description of workThe aim of the activity The spectral range of IR spectroscopy allows to probe the vibrational fingerprint of biomolecules. Evanescent wave in optical fiber interacts with environment, allowing identification of molecules at the basis of spectrum analysis
Description of workThe aim of the activity Main requirements to the glass properties to be used in FEWS: • transparent in IR up to 20 m; • good mechanical and thermodynamic properties (T=Tx–Tg> 100 oC); • well purified; Additional task: active fibers • transparent in visible or NIR (up to 1.5 m ); • glass with low phonon energy. • ability to introduce rare-earth ions; To ensure high solubility of rare-earth ions, the ChVS matrix should contain Ga additions Studied glasses: • Dopands • Pr3+ • Tb3+ • As-Se based • GaxTe20As30-xSe50; • Gax(As0.4Se0.6)100-x-yTey; • Ge-Se-Te based • Ga5Ge20Sb10Se65-xTex • Ga10Ge15Te75-xMx (M=Se, CsCl)
Description of workThe aim of the activity • Region of interest in the Vis/NIR for laser pumping • (optical band gap more than 0.8 eV (less than 1500nm) • Region of interest in the IR for biosensing • (up to 20m)
Description of workThe aim of the activity Tx – Tg > 100 oC For the successful fiber drawing difference between TxandTg should be at least 100 oC
Description of workThe aim of the activity • Why use RE? • To have secondary remote sources of light in the IR region from 1 to 10 m. • In case of Pr3+ the large numbers of bands in mid IR offers the promise of high-brightness sources for remote sensing. Energylevel diagrams of Pr3+ showing IR emission To ensure solubility of rare-earth elements, the glassy matrix should contain some additions like Ga
Description of workThe aim of the activity Effect of Ga-addition on solubility of RE Without Ga 1% of Ga
Outline • Overview • Description of work • Results • Conclusions Fourth Network-wide GlaCERCo workshop Rennes –October 22nd – 23rd, 2014
Results Gax(As0.4Se0.6)100-x system:Ga effects in glassy arsenic selenide Restricted functionality at high Ga content is caused by spontaneous crystallization. Ga2Se3 cubic phase, space group: Fourth Network-wide GlaCERCo workshop Rennes –October 22nd – 23rd, 2014
Results Ga2(As0.4Se0.6)98-yTey system: Teeffects in Ga-based arsenic selenide Te effects: (1) decrease in the phonon energy of glassy matrix and stretching in the IR transmittance ; (2) covalent bonds delocalization– long-wave shift in the fundamental optical absorption edge (decrease in Eg). The restricted functionality at high Te content is connected with spontaneous crystallization: Ga2Se3 cubic phase, space group:
Results Ga2(As0.4-zSbzSe0.6)98 system:AsSbeffects in Ga-based arsenic selenide glass Sb effects: (1) enhanced concentration limit (due toGa) in phase separation and crystallization; (2) metallization of chemical bonds – small long-wave shift in optical absorption edge (decrease in Eg). Partial substitution of As by Sb in As2Se3-based glass allows to introduce more Ga without crystallization
Results GaxTe20As30-xSe50 system (Ga-TAS-235):Ga effects in TAS-235 Glass forming region: (a) glasses (b)tendency to phase separation Restricted functionality at high Ga content is caused by spontaneous crystallization: Gа2 – the Rayleigh scattering on crystallites with character sizes of 200-300 nm; Gа5 – the Rayleigh scattering + the Mie scattering on intrinsic microscopic inhomogeneities. Ga2 • - dominant crystalline phase under small Ga content (3–5 %)is • HT-modification of cubic -Ga2Se3. • additional extractions of cubic -Ga2Se3appear under higherGacontent (above 5 %). Ga5 Micrographs of Gа1 surface (homogeneous glass),Gа2 (droplets of homogeneous nano- inclusions of -Ga2Se3cubic phase with 200–300 nm diameter)and Gа5microcrystallitesof - and - Ga2Se3cubic phases with more than 10 m size).
Results Ga5Ge20Sb10Se65-xTex system :Te effects
Results RE doping and fiber drawing of Ga2(As0.4Se0.6)88Te10 glass Optical loss spectra in fiber drawn from glassy Ga2(As0.4Se0.6)88Te10alloy, doped with 500 ppm Pr3+ (insert – micrograph of fiber cross section). Optical transmission spectra of glassy samples RE1 and RE2 as compared with Ga2(As0.4Se0.6)88Te10. Optical loss spectra in fiber drawn from glassy Ga2(As0.40Se0.60)88Te10 alloy, purified via single-step (black line) and three-step distillation (red line).
Outline • Overview • Description of work • Results • Conclusions Fourth Network-wide GlaCERCo workshop Rennes –October 22nd – 23rd, 2014
Conclusions (I) • Glass forming ability of Ga-doped chalcogenides of ~100 compositions, such as • GaxAs30-xSe50Te20 • Gax(As0.4Se0.6)100-x-yTey • Ga5Ge25Se70-xTex • Ga5Ge20Sb10Se65-xTex • Ga10Ge15Te75-xSex • Ga10Ge15Te75-CsCl • was studied; • It was established that Ga2Se3 crystalline phase is destroying covalent-bonding network arrangement of the most glassy systems which were studied; • Selected compositions were successfully doped with rare-earth elements and drawn into fibers.