Sc-doped GeTe thin films prepared by radio-frequency magnetron sputtering.

Radio frequency magnetron co-sputtering method employing GeTe and Sc targets was exploited for the deposition of Sc doped GeTe thin films. Different characterization techniques (scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffraction, atomic force microscopy, sheet resistance temperature-dependent measurements, variable angle spectroscopic ellipsometry, and laser ablation time-of-flight mass spectrometry) were used to evaluate the properties of as-deposited (amorphous) and annealed (crystalline) Ge-Te-Sc thin films. Prepared amorphous thin films have GeTe, GeTeSc, GeTeSc, GeTeSc and GeTeSc chemical composition.

Surface functionalization of a chalcogenide IR photonic sensor by means of a polymer membrane for water pollution remediation.

Rapid, simultaneous detection of organic chemical pollutants in water is an important issue to solve for protecting human health. This study investigated the possibility of developing an reusable optical sensor capable of selective measurements utilizing a chalcogenide transducer supplemented by a hydrophobic polymer membrane with detection based on evanescent waves in the mid-infrared spectrum. In order to optimise a polyisobutylene hydrophobic film deposited on a chalcogenide waveguide, a zinc selenide prism was utilized as a testbed for performing attenuated total reflection with Fourier-transform infrared spectroscopy.

Volume detection based on porous silicon waveguide for CO mid-infrared spectroscopy.

A mid-infrared (mid-IR) porous silicon (PSi) waveguide gas sensor was fabricated. PSi guiding and confinement layers were prepared by electrochemical anodization. Ridge waveguides were patterned using standard i-line photolithography and reactive ion etching.

Praseodymium-Doped GeInSbSe Films Based on Argon Plasma Cosputtering for Infrared-Luminescent Integrated Photonic Circuits.

In this paper, we report on the infrared luminescence of amorphous praseodymium-doped GeInSbSe waveguides, which can be used as infrared sources in photonic integrated circuits on silicon substrates. Amorphous chalcogenide thin films were deposited by radiofrequency magnetron cosputtering using an argon plasma whose deposition parameters were optimized for chalcogenide materials. The micropatterning as ridge waveguides of the chalcogenide cosputtered films was performed using photolithography and plasma-coupled reactive ion etching techniques.

Ionic Conductivity and Structure of Glasses Synthesized by Mechanical-Milling Methods in the [NaS]-(100 - ) [0.5GeS-0.5GaS] System.

Chalcogenide glasses in the NaS-GeS-GaS pseudoternary system were synthesized using a combination route of melt-quenching and mechanical-milling methods. First, a glass rich in germanium (90GeS-10GaS) is synthesized by melt-quenching synthesis in a silica tube sealed under vacuum. This glass is used as a precursor for the second step of mechanochemistry to explore the NaS-GeS-GaS pseudoternary system.

Carbon dioxide mid-infrared sensing based on Dy-doped chalcogenide waveguide photoluminescence.

Climate-active gases, notably carbon dioxide (CO), methane (CH), and nitrous oxide (NO), display fundamental absorption bands in the mid-infrared (mid-IR). The detection and monitoring of those gases could be enabled by the development of mid-IR optical sources. Broadband mid-IR on-chip light emission from rare-earth-doped chalcogenide photonic integrated circuits could provide a compact, efficient, and cost-effective gas sensing solution.

Surface Functionalization with Polymer Membrane or SEIRA Interface to Improve the Sensitivity of Chalcogenide-Based Infrared Sensors Dedicated to the Detection of Organic Molecules.

Priority substances likely to pollute water can be characterized by mid-infrared spectroscopy based on their specific absorption spectral signature. In this work, the detection of volatile aromatic molecules in the aqueous phase by evanescent-wave spectroscopy has been optimized to improve the detection efficiency of future optical sensors based on chalcogenide waveguides. To this end, a hydrophobic polymer was deposited on the surface of a zinc selenide prism using drop and spin-coating methods.

Tailoring of Multisource Deposition Conditions towards Required Chemical Composition of Thin Films.

The model to tailor the required chemical composition of thin films fabricated via multisource deposition, exploiting basic physicochemical constants of source materials, is developed. The model is experimentally verified for the two-source depositions of chalcogenide thin films from Ga-Sb-Te system (tie-lines GaSb-GaTe and GaSb-Te). The thin films are deposited by radiofrequency magnetron sputtering using GaSb, GaTe, and Te targets.

Prediction of fatty acids composition in the rainbow trout Oncorhynchus mykiss by using Raman micro-spectroscopy.

The importance of poly-unsaturated fatty acids (PUFAs) in food is crucial for the animal and human development and health. As a complementary strategy to nutrition approaches, genetic selection has been suggested to improve fatty acids (FAs) composition in farmed fish. Gas chromatography (GC) is used as a reference method for the quantification of FAs; nevertheless, the high cost prevents large scale phenotyping as needed in breeding programs.

Genetic architecture and genomic selection of fatty acid composition predicted by Raman spectroscopy in rainbow trout.

Background: In response to major challenges regarding the supply and sustainability of marine ingredients in aquafeeds, the aquaculture industry has made a large-scale shift toward plant-based substitutions for fish oil and fish meal. But, this also led to lower levels of healthful n-3 long-chain polyunsaturated fatty acids (PUFAs)-especially eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids-in flesh. One potential solution is to select fish with better abilities to retain or synthesise PUFAs, to increase the efficiency of aquaculture and promote the production of healthier fish products.

Arsenic-Doped SnSe Thin Films Prepared by Pulsed Laser Deposition.

Pulsed UV laser deposition was exploited for the preparation of thin Sn As Se ( = 0, 0.05, 0.5, and 2.

Toward Chalcogenide Platform Infrared Sensor Dedicated to the In Situ Detection of Aromatic Hydrocarbons in Natural Waters via an Attenuated Total Reflection Spectroscopy Study.

The objective of this study is to demonstrate the successful functionalization of the surface of a chalcogenide infrared waveguide with the ultimate goal of developing an infrared micro-sensor device. First, a polyisobutylene coating was selected by testing its physico-chemical compatibility with a Ge-Sb-Se selenide surface. To simulate the chalcogenide platform infrared sensor, the detection of benzene, toluene, and ortho-, meta- and para-xylenes was efficaciously performed using a polyisobutylene layer spin-coated on 1 and 2.

Co-sputtered Pr-doped Ga-Ge-Sb-Se active waveguides for mid-infrared operation.

This work reports on the properties of luminescent waveguides based on quaternary Ga-Ge-Sb-Se amorphous thin films doped with praseodymium. The waveguides were fabricated via magnetron co-sputtering, followed by inductively coupled plasma reactive ion etching. The initial thin film thickness and optical properties were assessed and the spectroscopic properties of the waveguides were measured.

Comparative study of Er-doped Ga-Ge-Sb-S thin films fabricated by sputtering and pulsed laser deposition.

Despite the renewed interest in rare earth-doped chalcogenide glasses lying mainly in mid-infrared applications, a few comprehensive studies so far have presented the photoluminescence of amorphous chalcogenide films from visible to mid-infrared. This work reports the fabrication of luminescent quaternary sulfide thin films using radio-frequency sputtering and pulsed laser deposition, and the characterization of their chemical composition, morphology, structure, refractive index and Er photoluminescence. The study of ErI level lifetimes enables developing suitable deposition parameters; the dependency of composition, structural and spectroscopic properties on deposition parameters provides a way to tailor the RE-doped thin film properties.

Linear and nonlinear optical properties of co-sputtered Ge-Sb-Se amorphous thin films.

Amorphous Ge-Sb-Se thin films were co-sputtered from ${{\rm GeSe}_4}$GeSe and ${{\rm Sb}_2}{{\rm Se}_3}$SbSe targets. Depending on the film composition, linear optical properties were studied by ellipsometry. The Kerr coefficient and two-photon absorption coefficient were estimated using Sheik-Bahae's formalism for co-sputtered films of ${{\rm GeSe}_4} {\text -} {\rm Sb}_2{{\rm Se}_3}$GeSe-SbSe compared to ${{\rm GeSe}_2}{\text -}{\rm Sb}_2{{\rm Se}_3}$GeSe-SbSe pseudo-binary system and ${{\rm As}_2}{{\rm Se}_3}$AsSe as reference.

GaTe-SbTe thin-films phase change characteristics.

A radio frequency magnetron co-sputtering technique exploiting GaTe and ${\rm Sb}_2 {\rm Te}_3$SbTe targets was used for the fabrication of Ga-Sb-Te thin films. Prepared layers cover broad region of chemical composition (${\sim}{10.0 {-} 26.

Anodic bonding of mid-infrared transparent germanate glasses for high pressure - high temperature microfluidic applications.

High pressure/high-temperature microreactors based on silicon-Pyrex® microfabrication technologies have attracted increasing interest in various applications providing optical access in high-pressure flow processes. However, they cannot be coupled to infrared spectroscopy due to the limited optical transparency (up to ~2.7 μm in the infrared region) of the Pyrex® glass substrate employed in the microreactor fabrication.

Amorphous Ge-Bi-Se Thin Films: A Mass Spectrometric Study.

The Ge-Bi-Se thin films of varied compositions (Ge content 0-32.1 at. %, Bi content 0-45.

Comparison of Clusters Produced from SbSe Homemade Polycrystalline Material, Thin Films, and Commercial Polycrystalline Bulk Using Laser Desorption Ionization with Time of Flight Quadrupole Ion Trap Mass Spectrometry.

This study compared SbSe material in the form of commercial polycrystalline bulk, sputtered thin film, and homemade polycrystalline material using laser desorption ionization (LDI) time of flight mass spectrometry with quadrupole ion trap mass spectrometry. It also analyzed the stoichiometry of the SbSe clusters formed. The results showed that homemade SbSe bulk was more stable compared to thin film; its mass spectra showed the expected cluster formation.

Ge-Sb-Te Chalcogenide Thin Films Deposited by Nanosecond, Picosecond, and Femtosecond Laser Ablation.

Ge-Sb-Te thin films were obtained by ns-, ps-, and fs-pulsed laser deposition (PLD) in various experimental conditions. The thickness of the samples was influenced by the Nd-YAG laser wavelength, fluence, target-to-substrate distance, and deposition time. The topography and chemical analysis results showed that the films deposited by ns-PLD revealed droplets on the surface together with a decreased Te concentration and Sb over-stoichiometry.

7 to 8 µm emission from Sm doped selenide fibers.

We report on the observation of the long wave-infrared (LWIR) emission centered at 7.3 µm of Sm doped chalcogenide fibers. The chemical composition of the selenide glass host matrix (GaGeSbSe) enables the drawing of 500 ppm and 1000 ppm Sm doped fibers.

Co-doped Dy and Pr GaGeSbS fibers for mid-infrared broad emission.

Rare earth ion doped materials are means to obtain cost-effective infrared light sources, with enough brilliance for applications such as gas sensing. Within a sulfide matrix, the simultaneous luminescence of both Pr and Dy in the GaGeSbS glass is reported. The use of these two rare earths is giving rise to a broad continuous luminescence in the 2.

8 μm luminescence from a Tb GaGeSbSe fiber.

In this Letter, we report for the first time, to the best of our knowledge, on an emission at 8 μm from Tb-doped GaGeSbSe chalcogenide fibers with doping levels at 1000 ppm and 500 ppm. These fibers were drawn following conventional melt-quenching methods and pumped at 2.05 μm using a Tm: YAG laser.

Laser Desorption Ionization of AsCh (Ch = S, Se, and Te) Chalcogenides Using Quadrupole Ion Trap Time-of-Flight Mass Spectrometry: A Comparative Study.

Laser desorption ionization using time-of-flight mass spectrometer afforded with quadrupole ion trap was used to study AsCh (Ch = S, Se, and Te) bulk chalcogenide materials. The main goal of the study is the identification of species present in the plasma originating from the interaction of laser pulses with solid state material. The generated clusters in both positive and negative ion mode are identified as 10 unary (S and As ) and 34 binary (As S ) species for AsS glass, 2 unary (Se ) and 26 binary (As Se ) species for AsSe glass, 7 unary (Te ) and 23 binary (As Te ) species for AsTe material.