New Publications are available for Infrared and Raman spectra and scattering (condensed matter)
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New Publications are available now online for this publication.
Please follow the links to view the publication.<i xmlns="http://pub2web.metastore.ingenta.com/ns/">In situ</i> synthesis of highly qualified TBA-silicalite-2 zeolite membranes on biomorphous charcoal supports
http://dl-live.theiet.org/content/journals/10.1049/mnl.2012.0503
Highly qualified tetrabutylammonium (TBA)-silicalite-2 layers were successfully grown via a simple <i xmlns="http://pub2web.metastore.ingenta.com/ns/">in situ</i> hydrothermal synthesis in microchannels of biomorphic porous charcoals from the reactant system TBAOH–TEOS–H<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O. All the charcoal supports were previously oxidised and vacuum-infiltrated to favour the anchoring of the silicalite-2 crystals. The as-prepared products were characterised in detail by power X-ray diffraction, Fourier transform infrared spectra and field emission scanning electron microscopy. The experimental results indicate that the uniform and dense TBA-silicalite-2 zeolite membranes consisting of spherical and columnar crystals were prepared on the inner surface of biomorphic charcoal by different synthesis temperatures and times. As a new zeolite adsorbent hybrid material, the silicalite-2 zeolite/porous charcoal composite was evaluated by the N<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> adsorption–desorption isotherm tests, which exhibit high-Brunauer–Emmett–Teller surface area and microspore volume with 168 m<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sup>/g<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">1</sup> and 0.05 cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sup>/g<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">1</sup>, respectively. The obtained charcoal–zeolite membranes may have potential applications in catalysis and separation.Alter the sheet resistance of carbon nanotube-coated cellulose fabric with argon plasma pretreatment
http://dl-live.theiet.org/content/journals/10.1049/mnl.2012.0431
Cellulose fabrics were coated with single-walled carbon nanotubes (SWCNTs) by a dip-drying process. Scanning electron microscopy (SEM) and Raman spectroscopy analyses indicate the attachment of SWCNTs. The sheet resistance of SWCNT-coated fabrics can be altered by modifying the raw cellulose fabrics with low-pressure argon plasma. An initial plasma ablation of up to 3 min results in the decrease of sheet resistance, which can be ascribed to the increase of fibre surface roughness, evidenced by SEM analyses. A further increase in the extent of plasma ablation brings about the increase in sheet resistance, which is associated with the incorporation of oxygen functionalities, supported by the data obtained on colour strength measurements.Interaction of polymethacrylate-<i xmlns="http://pub2web.metastore.ingenta.com/ns/">g</i>-PEO comb copolymers with natural bentonite in aqueous systems
http://dl-live.theiet.org/content/journals/10.1049/mnl.2012.0251
Natural bentonite was successfully modified using polymethacrylate-<i xmlns="http://pub2web.metastore.ingenta.com/ns/">g</i>-polyethylene oxide (PEO) comb copolymer. Changes in the surfaces and microstructure of the resultant organo-bentonite were characterised by Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy and high-resolution transmission electron microscopy, respectively. FTIR results indicated the presence of the copolymer on the surface of organo-bentonite. XRD measurements showed that the copolymer molecules were intercalated into the bentonite layers. TG analysis and electron microscopy micrographs demonstrated the interlayers of bentonite were intercalated by the copolymers with surface adsorption to a certain extent.Characterisation of protein adsorption on different liquid crystal phthalocyaninethin films
http://dl-live.theiet.org/content/journals/10.1049/iet-nbt.2009.0011
Bovine serum albumin (BSA) protein adsorption on thin spun films of different metal octakishexylthiophthalocyanine [(C<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub>S)<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sub>PcM, M=Cu, Ni] derivatives is investigated by using three independent spectroscopic measurements namely Raman spectroscopy, ellipsometry and surface plasmon resonance imaging. Thermally induced molecular self-reorganisations in the phthalocyanine films are found to have produced the changes in the surface energy which, in turn, control protein adsorption. The amount of BSA adsorption on [(C<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub>S)<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sub>PcNi] is more limited than that on [(C<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub>S)<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sub>PcCu] and this observation is consistent with the results on the surface wettability obtained from the contact angle measurements. The shift from the plasmonic resonance wavelength because of the BSA adsorption was significantly larger for the heat-treated [(C<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub>S)<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sub>PcCu] than as-deposited film. Similar measurements on the [(C<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub>S)<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sub>PcNi] films showed a limited BSA adsorption. The results of surface plasmon resonance experiments are consistent with those obtained from Raman spectroscopic and ellipsometric techniques.Functionalisation of nylon with carbon nanotubes to make thermally stable fabric and wearable capacitor
http://dl-live.theiet.org/content/journals/10.1049/mnl.2011.0726
Single-walled carbon nanotubes (SWCNT) are dispersed in water and attached to nylon fabric by a simple immersing–drying procedure, which is evidenced by data obtained using Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Thermalgravimetric analysis reveals the temperature at which the functionalised nylon fabric reaches its maximum weight loss rate increases about 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">o</sup>C with respect to the pristine nylon. This improvement in thermal oxidation stability can be ascribed to the strong free-radical accepting capacity of nanotubes and their high thermal conductivity. The SWCNT functionalised nylon is then used to make a capacitor structure, which possesses the merits of being lightweight, little hysteresis and low power dissipation.Synthesis of carbon nanotubes by combustion of a paraffin wax candle
http://dl-live.theiet.org/content/journals/10.1049/mnl_20070035
A method for the synthesis of multi-walled carbon nanotubes (MWCNTs) using paraffin wax candles is reported. The MWCNTs were grown on a cobalt-coated silicon wafer with a combustion rate of 80 s at a flame temperature of 700°C. The MWCNTs are 15–20 nm in diameter and ∼1–3 µm in length. Raman spectroscopy revealed that the <i xmlns="http://pub2web.metastore.ingenta.com/ns/">I</i><sub xmlns="http://pub2web.metastore.ingenta.com/ns/">G</sub>/<i xmlns="http://pub2web.metastore.ingenta.com/ns/">I</i><sub xmlns="http://pub2web.metastore.ingenta.com/ns/">D</sub> ratio is 0.88. The growth of the MWCNTs was studied using different combustion times. The amount of MWCNTs decreased for experiments longer than 80 s, presumably because the MWCNTs were burned off with a long stay in the flame.Properties of graphene produced by the high pressure–high temperature growth process
http://dl-live.theiet.org/content/journals/10.1049/mnl_20070074
The authors report on a new method for the synthesis of graphene, a mono-layer of carbon atoms arranged in a honey comb lattice, and the assessment of the properties of obtained graphene layers using micro-Raman characterisation. Graphene was produced by a high pressure–high temperature (HPHT) growth process from the natural graphitic source material by utilising the molten Fe–Ni catalysts for dissolution of carbon. The resulting large-area graphene flakes were transferred to the silicon–silicon oxide substrates for the spectroscopic micro-Raman and scanning electron microscopy inspection. The analysis of the <i xmlns="http://pub2web.metastore.ingenta.com/ns/">G</i> peak, <i xmlns="http://pub2web.metastore.ingenta.com/ns/">D</i>, <i xmlns="http://pub2web.metastore.ingenta.com/ns/">T</i>+<i xmlns="http://pub2web.metastore.ingenta.com/ns/">D</i> and 2<i xmlns="http://pub2web.metastore.ingenta.com/ns/">D</i> bands in the Raman spectra under the 488 nm laser excitation indicate that the HPHT technique is capable of producing high-quality large-area single-layer graphene with a low defect density. The disorder-induced <i xmlns="http://pub2web.metastore.ingenta.com/ns/">D</i> peak ∼1359 cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> while very strong in the initial graphitic material is completely absent in the graphene layers. The proposed method may lead to a more reliable graphene synthesis and facilitate its purification and chemical doping.Inkjet printing of palladium alkanethiolates for facile fabrication of metal interconnects and surface-enhanced Raman scattering substrates
http://dl-live.theiet.org/content/journals/10.1049/mnl.2010.0109
Pd hexadecanethiolate and Pd butanethiolate precursors were patterned using inkjet printing techniques to form metallic Pd interconnects upon thermolysis. Patterns with lateral dimensions of ∼50 µm were produced. The surface morphology of the Pd interconnects was examined using scanning electron microscopy. By printing four-probe patterns, the resistance as a function of the precursor concentration was determined, allowing estimates for the resistivity of the printed interconnects. To demonstrate the utility of this fabrication approach, an electronic circuit consisting of single-wall carbon nanotubes was inkjet printed and then contacted with Pd pads. These printed patterns have also been applied as surface-enhanced Raman scattering substrates that exhibit high sensitivity.Template-assistant synthesis of gold nanoparticles with mesoporous silica thin films
http://dl-live.theiet.org/content/journals/10.1049/mnl.2011.0480
Three kinds of amino-functional mesoporous silica thin films (AF-MSTFs) have been directly synthesised by the sol–gel dip coating. The Fourier transform infrared spectra show that the amino groups are introduced into the nanopores of AF-MSTFs successfully by co-condensation technology. The X-ray diffraction (XRD) and transmission electron microscope (TEM) characterisations find that the AF-MSTFs prepared by different surfactants have highly ordered mesostructures with different nanopore sizes and morphologies. By using AF-MSTFs as templates, associated with neutralisation reaction and hydrogen reduction, gold nanoparticles (GNPs) are formed well within the mesostructures with a narrow size distribution, which is verified by the observation of XRD, TEM and energy-dispersive X-ray analyses. Ultraviolet–visible spectra of the nanocomposites are additional evidence of the existence of GNPs. What is more, they imply that the size effect of GNPs and the structure variation of AF-MSTFs can modulate the optical properties of the nanocomposites.Preparation and photocatalytic activity of Cu<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">2+</sup>-doped 2, 4-dichlorophenol molecularly imprinted SiO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>–TiO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> nanocomposite
http://dl-live.theiet.org/content/journals/10.1049/mnl.2009.0114
A Cu<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">2+</sup>-doped 2, 4-dichlorophenol (2, 4-DCP) molecularly imprinted TiO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>–SiO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> nanocomposite catalyst was prepared by molecular imprinting technique in combination with sol–gel methods. The prepared material was characterised by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> adsorption measurements. The photocatalytic ability and selectivity of the material was also evaluated. The results show that the Cu<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">2+</sup>-doped imprinted material not only has good capacity but also favourable selectivity towards the photocatalytic degradation of the target pollutant, which was shown to be promising for selective removal of 2, 4-DCP from environmental samples.Nanocomposite prepared by immobilising gelatin and hydroxyapatite on bacterial cellulose nanofibres
http://dl-live.theiet.org/content/journals/10.1049/mnl.2010.0209
In the present work, a nanocomposite was synthesised by immobilising gelatin and hydroxyapatite (HAp) on the surface of bacterial cellulose (BC) nanofibres via crosslinking and biomineralisation. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy were employed to characterise the BC/gelatin/HAp nanocomposites. It was found that gelatin was formed and enwrapped on the surface of BC nanofibres, and the HAp particles were successively precipitated on the fibres of BC/gelatin composite. Furthermore, the mesenchymal stem cells were seeded on the obtained samples to test the cell compatibility.Transparent ATO/epoxy nanocomposite coating with excellent thermal insulation property
http://dl-live.theiet.org/content/journals/10.1049/mnl.2011.0558
Transparent antimony-doped tin oxide (ATO)/epoxy nanocomposites, as glass thermal insulation coating, were prepared by incorporating ATO nanoparticles into a transparent epoxy matrix. The effect of ATO content on the optical and thermal insulation property of ATO/epoxy coating was studied. The results show that the ATO/epoxy coating with 1 wt% ATO has excellent optical properties, that is, visible light transmittance above 50% and shading coefficient of 0.54 are simultaneously achieved. In addition, the large temperature difference between the chambers coated respectively with the ATO/epoxy glass sheet and the common glass sheet indicates that the prepared ATO/epoxy nanocomposite coating has excellent thermal insulation property.Preparation of low-density TiO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>/poly(methyl methacrylate) composite particles by aqueous solution polymerisation
http://dl-live.theiet.org/content/journals/10.1049/mnl.2010.0206
Low-density TiO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>/poly (methyl methacrylate) composite particles were prepared by aqueous solution polymerisation in the presence of polyvinylpyrrolidone. The obtained composite particles were characterised by Fourier transform infrared spectra, field-emission scanning electron microscopy, transmission electron microscopy and differential thermal analysis–thermo gravimetric analysis. Results show that the composite particles with an average grain size of 189 nm and an estimated density of 1.55 g/cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sup> are successfully prepared.Formation of silica nanocapsules from nanoemulsions obtained by the phase inversion temperature method
http://dl-live.theiet.org/content/journals/10.1049/mnl.2009.0085
A method for preparation of silica nanocapsules is described, by interfacial polymerisation of nanoemulsions which are prepared by the phase inversion temperature (PIT) method. This is a low-energy emulsification technique which does not require any special equipment, such as high-pressure homogenisers. The nanoemulsions were prepared with decane as the oil phase, in which tetraethoxysilane (TEOS) was dissolved with an ethoxylated alcohol as the surfactant. The hydrolysis and polymerisation of the TEOS was performed under acidic and basic conditions using HCl and ammonia, respectively. The obtained nanocapsules with an average size between 100 and 300 nm, which were comprised of an oil core (decane) and silica shell, were characterised using dynamic light scattering, fourier transform infrared spectroscopy (FTIR), high-resolution scanning electron microscopy (HR-SEM) and by fluorescence of an encapsulated solvatochromic dye. The capsules could be positively or negatively charged by adsorption of ionic surfactants after they were formed.Synthesis and characterisations of poly(aniline-co-<i xmlns="http://pub2web.metastore.ingenta.com/ns/">o</i>/<i xmlns="http://pub2web.metastore.ingenta.com/ns/">m</i>-toluidine)/Sb<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> nanocomposites
http://dl-live.theiet.org/content/journals/10.1049/mnl.2010.0065
This study is focused on the preparation and characterisation of conducting poly(aniline-co-<i xmlns="http://pub2web.metastore.ingenta.com/ns/">o</i>/<i xmlns="http://pub2web.metastore.ingenta.com/ns/">m</i>-toluidine)/Sb<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> nanocomposites. These nanocomposites were synthesised by the oxidative chemical polymerisation with peroxydisulphate as an oxidant in aqueous hydrochloric acid (HCl) medium and Sb<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> as a nanomaterial under different experimental conditions. The nanocomposites were characterised by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis, high-resolution transmission electron microscopy and conductivity measurements. FTIR-based kinetics was proposed based on the relative intensities of FTIR peaks.Influence of synthesis temperature on synthesis of PVA-stabilised silver nanoparticles
http://dl-live.theiet.org/content/journals/10.1049/mnl.2011.0516
Polyvinyl alcohol (PVA)-stabilised silver nanoparticles have been synthesised by the simple reduction process at different temperatures ranging from 60 to 90°C. The as-synthesised silver nanoparticles were analysed by X-ray diffraction (XRD), energy-dispersive analysis of X-rays, transmission electron microscope, UV–vis absorption spectroscopy and Fourier transform infrared (FTIR) spectroscopy. XRD studies showed that the samples exhibited cubic structure. The average particle size was found to be ∼50 nm. FTIR spectra revealed that the synthesised nanoparticles were successively capped by PVA. Optical absorption spectra confirmed the uniformity of as-prepared silver nanoparticles and the absorption peak was observed in the range 390–421 nm.Fabrication of superhydrophobic surfaces with high adhesive forces towards water on steel substrates
http://dl-live.theiet.org/content/journals/10.1049/mnl.2012.0175
The present Letter reports a simple and effective two-steps immersion method to fabricate superhydrphobic surfaces with high adhesive forces towards water on steel substrates. The steel plates were firstly immersed in the aqueous CuSO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub> solution for 20 s, and then immersed in the stearic acid ethanol solution for 24 h. The sample surfaces were characterised by scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectrophotometry, X-ray diffraction and optical contact angle measurements. The results show that, after two-steps immersion processes, the cupric stearate microspheres with binary micro/nanometre-scale rough structures are formed on the steel surfaces. The as-prepared steel surfaces exhibit a good high adhesive superhydrophobicity with a 166.3° water contact angle and no rolling angle. The high adhesive superhydrophobic surfaces on steel substrates have a good potential application in no loss liquid transportation.Electrochemical polymerisation of poly(3-bromothiophene)/WO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> nanocomposite films
http://dl-live.theiet.org/content/journals/10.1049/mnl.2011.0038
Poly(3-bromothiophene) (PBrT) was electrochemically synthesised on nano-WO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> surface in the ionic liquid 1-butyl-3-metyllimidazolium hexafluorophosphate ([BMIM]PF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub>) by potentiodynamic method. The PBrT/WO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> films were characterised by Fourier transform infrared spectroscopies, scanning electron microscopy and energy-dispersive X-ray analysis. Electrochemistry properties of the prepared PBrT/WO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> films were characterised by cyclic voltammetry. The obtained PBrT/WO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> nanocomposite films displayed a significant enhancement of electrochemical activity than that of pure WO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> and PBrT films.Facile synthesis of Ag–Fe<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> core–shell composite nanoparticles by an <i xmlns="http://pub2web.metastore.ingenta.com/ns/">in situ</i> method
http://dl-live.theiet.org/content/journals/10.1049/mnl.2010.0149
A new synthetic method of Ag–Fe<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> core–shell composite nanoparticles is reported. The silver nanoparticles used as the seeds was synthesised by an <i xmlns="http://pub2web.metastore.ingenta.com/ns/">in situ</i> method in the presence of <i xmlns="http://pub2web.metastore.ingenta.com/ns/">p</i>-toluenesulfonic acid-doped polyaniline. Then the Fe<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> was coated on the surface of silver nanoparticles in the dimethylformamide solution. The core–shell structure of Ag–Fe<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> composite nanoparticles was confirmed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and UV-vis spectroscopy. The result showed that the average size of the Ag core and average thinkness of the Fe<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> shell are 38.0 and 5.5 nm, respectively. It provides an opportunity to synthesise other core–shell (Fe<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>O<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>) nanoparticles by one experiment.Emis data reviews. Properties of amorphous silicon: a book of EMIS data reviews
http://dl-live.theiet.org/content/journals/10.1049/ip-i-1.1985.0049
Profile dependence and measurement of absolute Raman scattering cross-section in optical fibres
http://dl-live.theiet.org/content/journals/10.1049/el_19891008
A simple measurement method for the absolute Raman scattering cross-section of an optical fibre is presented. This method does not require a high power pump laser and it measures the fibre directly. It is also shown that the calculation of the cross-section depends on the fibre structure, such as its refractive index profile and the differential attenuation between the pump wavelength and Raman wavelength.Multiphonon absorption in infra-red fluoride glasses
http://dl-live.theiet.org/content/journals/10.1049/el_19820137
Measurements of the infra-red edge absorption against frequency have been performed with both ZrF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub> and HfF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub> fluoride glasses. Results show that absorption in the 1600–1200 cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> frequency range (6–8 μm band) originates from multiphonon processes and depends on the glass composition.Raman spectra of hydrogen-treated optical fibres
http://dl-live.theiet.org/content/journals/10.1049/el_19840122
Chemical reactions in a Ge-P-silicate optical fibre exposed to hydrogen at 100 bar and 150°C for times up to 120 h are studied by Raman spectroscopy. Hydride and hydroxyl groups are formed, as Si-H and P-OH. The reaction kinetics are consistent with a defect-related mechanism. The saturation concentration of hydroxyl is about 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sup> ppm.Infra-red loss spectrum of hydrogen molecules in a silica fibre
http://dl-live.theiet.org/content/journals/10.1049/el_19830709
An infra-red loss spectrum of hydrogen molecules diffused into a fibre is reported, and assignments of loss peaks are discussed. It is found that there are ten loss peaks between 1.5 and 2.5 μm which are closely connected with the fundamental vibration mode of the hydrogen molecules.Nitrogen-related absorption bands in optical fibres
http://dl-live.theiet.org/content/journals/10.1049/el_19870101
Two absorption bands are reported in germanium-doped optical fibres containing low levels of nitrogen. The bands are not present in the fibre as drawn, but can be activated by exposure to elevated temperatures. Germanium, along with nitrogen, plays a role in forming the defects responsible for the absorption.New interpretation of structure of thermally grown silicon dioxide
http://dl-live.theiet.org/content/journals/10.1049/el_19870299
New evidence suggesting that the structure of thermally grown silicon dioxide films may not be totally amorphous is presented. Mathematical deconvolution of the Si—O absorption at 1075 cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> consistently reveals two distinct Gaussian lineshapes. Possible sources for these derived peaks are discussed.Hydrogen and deuterium gas-in-glass effects in single-mode optical fibres
http://dl-live.theiet.org/content/journals/10.1049/ip-j.1985.0037
The effect of molecular hydrogen on the attenuation spectra of single-mode optical fibres has been studied at ambient temperatures for a range of hydrogen pressures. From studies of the analogous deuterium spectra, peaks observed in the 1.0–1.3 µm region have been assigned to combination vibrational absorption effects, with two new peaks having been identified at 1.143 and 1.33 µm. An out-diffusion coefficient of 1.4 × 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−11</sup> cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sup> s<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> has been determined for deuterium in silica fibres at 20°C.Low-energy erbium implanted Si<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>N<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub>/SiO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub>/Si waveguides
http://dl-live.theiet.org/content/journals/10.1049/el_19921441
Photoluminescence spectroscopy studies of low energy erbium and erbium/oxygen-implanted silicon-nitride waveguides are compared. Emission spectra show peaks at 1533 and 1548nm. The optimum annealing temperature is determined to be 1175°C, yielding lifetimes up to 7ms and a several decade intensity increase. Er implantation yields more than 40% longer lifetime and higher intensity than Er/O.Use of rotational sideband absorption for high sensitivity methane detection with a 1.64 μm DFB laser
http://dl-live.theiet.org/content/journals/10.1049/el_19921345
High sensitivity methane detection using a 1.64 μm DFB laser in the rotational sideband of the <sup xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sup><i xmlns="http://pub2web.metastore.ingenta.com/ns/">v</i><sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> overtone region is demonstrated. A sensitivity of 2 ppm.m was achieved which is comparable with recent measurements in the purely vibrational Q branch and therefore relaxes the wavelength constraints of DFB lasers for methane sensing.Methane and carbon dioxide sensing using a DFB laser diode operating at 1.64 μm
http://dl-live.theiet.org/content/journals/10.1049/el_19930374
Selective gas sensing of CH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub> and CO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> using a single tunable 1.64 μm DFB laser diode is demonstrated for the first time. By precise wavelength tuning of the diode to non-coincident absorptions of the two gases in their overlapping spectral region we can detect both using absorption spectroscopy.