Non-linear optical materials
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Recent papers in Non-linear optical materials
TeO2 –WO3 –Pb3O4 glasses codoped with Er3+ – Yb3+ ions have been prepared by melting and quenching process. Judd–Ofelt analysis has been performed to calculate the various radiative parameters viz., radiative lifetime , branching ratio... more
TeO2 –WO3 –Pb3O4 glasses codoped with Er3+ – Yb3+ ions have been prepared by melting and quenching process. Judd–Ofelt analysis has been performed to calculate the various radiative parameters viz., radiative lifetime , branching ratio and stimulated emission crosssections by using the absorption spectra. The nephelauxetic ratio, bonding and covalency parameters have been determined to get the information about the nature of bonding between the rare earth ions and neighbouring oxygen atoms. The near infrared (NIR) to visible frequency upconversion (UC) study upon excitations with 980 nm and 808 nm diode lasers has been performed. The variations observed in the UC emission intensity arising from the Er 3? ions have been explained on the basis of efficient energy transfer Yb3+ - Er3+ ions and back energy transfer Er3+-Yb3+ processes. On codoping with Yb 3? ions the intensity of the UC emission bands observed in the codoped glass upon excitation at 980 nm has been enhanced by many folds and explained on the basis of the oscillator strengths, UC emission crosssection and temporal evolution analysis. No tuning in the colour emitted from the codoped glass upon excitation at 980 nm is reported. The results suggested that the codoped glass may be suitable in making the NIR to visible upconverter and colour non-tunable optical devices.
L-histidine cadmium chloride monohydrate (LHCCM), a semiorganic nonlinear optical material was grown from aqueous solution by slow solvent evaporation method at room temperature. The LHCCM crystals were characterized by X-ray powder... more
L-histidine cadmium chloride monohydrate (LHCCM), a semiorganic nonlinear optical material was grown from aqueous solution by slow solvent evaporation method at room temperature. The LHCCM crystals were characterized by X-ray powder diffraction analysis. The presence of functional groups was identified through fourier transform infrared spectroscopy. Thermogravimetric and differential thermal analysis confirms that the crystal is stable up to 277°C. The dielectric constant was studied as a function of frequency for various temperatures. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester. The second harmonic generation behavior of LHCCM crystal was tested by modified Kurtz-Perry powder technique.
- by J Chandrasekaran and +1
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- Physics, Chemistry, Non-linear optical materials
Gold nanoparticles (NPs) exhibit strong surface plasmon resonance (SPR) in the visible spectral region. Lithium Zinc Calcium Fluoroborate glasses embedded with Au NPs were synthesized by conventional melt quench technique. The gold NPs... more
Gold nanoparticles (NPs) exhibit strong surface plasmon resonance (SPR) in the visible spectral region. Lithium Zinc Calcium Fluoroborate glasses embedded with Au NPs were synthesized by conventional melt quench technique. The gold NPs embedded glasses exhibited dichroic nature. A small kink around 44.61 ∘ in the X-ray diffraction (XRD) pattern suggests the presence of Au (2 0 0) in the matrix. High resolution-transmission electron microscopic (HR-TEM) measurements further confirmed the existence of spherical and ellipsoidal Au NPs. Thermogravimetric analysis (TGA) reveals the role of network modifiers in the matrix as the glasses that contained higher concentration of lithium oxide exhibits lower T g thereby resulting in creation of more non bridging oxides (NBO's). The Z-Scan studies were performed under non-resonant condition (800 nm) to analyze the application of these glasses for optical limiting devices.
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