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Petric M.,Jozef Stefan Institute | Petric M.,Jozef Stefan International Postgraduate School | Bohinc R.,Jozef Stefan Institute | Bucar K.,Jozef Stefan Institute | And 5 more authors.
Inorganic Chemistry | Year: 2016

The electronic structure of phosphorus, sulfur, and chlorine in compounds with Td and C3v local symmetries was studied with high-resolution Kβ X-ray emission spectroscopy (XES) in the tender X-ray range. Measured spectra are compared to the results of ab initio quantum chemical calculations based on density functional theory (DFT). The spectral structure is reproduced by the model spectra of isolated XO4n- and XO3n-(X = P, S, or Cl) anions incorporating only the first coordination sphere around the central atom. The main spectral components can be explained by the molecular orbital theory. Finally, the potential of XES spectroscopy combined with DFT calculations to study the electronic structure of third-row elements in a slightly larger molecule is investigated. © 2016 American Chemical Society. Source


Yue F.,Max Born Institute For Nichtlineare Optik Und Kurzzeitspektroskopie | Yue F.,East China Normal University | Tomm J.W.,Max Born Institute For Nichtlineare Optik Und Kurzzeitspektroskopie | Kruschke D.,Institute fur Angewandte Photonik E.V. | And 3 more authors.
Optics Express | Year: 2013

Silicate- and borosilicate-based PbS:glass material and borosilicate-glass-based fibers are fabricated and analyzed. Optical properties including absorption and emission are characterized and related to growth and annealing conditions. In silicate glasses PbS volume fractions of exceeding 0.4 percent and almost octave-spanning emission spectra with a halfwidth of 940 nm are achieved. Fiber bundles with a core being surrounded by three PbS:Glass fibers are pulled. A confinement factor of Γ = 0.00406 is determined. Emission properties, in particular emission bandwidth, are subsequently tuned and spectrally widened by annealing fibers in a gradient furnace. The results pave the way towards optically pumped broad-bandwidth light emitters based either on 'bulk' PbS:glass or PbS:glass-based fibers. © 2013 Optical Society of America. Source


Moreels I.,Italian Institute of Technology | Kruschke D.,Institute fur Angewandte Photonik E.V. | Glas P.,Institute for Scientific Instruments GmbH | Tomm J.W.,Max Born Institute For Nichtlineare Optik Und Kurzpulsspektroskopie
Optical Materials Express | Year: 2012

The dielectric function of PbS quantum dots (Qdots) with diameters of 3.5-5.0 nm in glass matrix is determined from transmission measurements by Maxwell-Garnett effective medium theory combined with iterative Kramers-Kronig analysis. The algorithm used provides real and imaginary part of the dielectric function in the 200-1800 nm spectral range, for both Qdot-doped glasses as well as the PbS Qdots alone. The latter data are compared with the results obtained from colloidal PbS quantum dots and, within the limits of the experimental error, agreement is found. © 2012 Optical Society of America. Source


Yue F.,Max Born Institute For Nichtlineare Optik Und Kurzzeitspektroskopie | Yue F.,East China Normal University | Tomm J.W.,Max Born Institute For Nichtlineare Optik Und Kurzzeitspektroskopie | Kruschke D.,Institute fur Angewandte Photonik E.V. | Glas P.,Institute for Scientific Instruments GmbH
Laser and Photonics Reviews | Year: 2013

The luminescence behavior of PbS-quantum dots in glass matrix (PbS:Glass) is investigated. Steady-state and time-resolved photoluminescence are applied in a wide range of excitation densities up to pulse energies exceeding 50 μJ/cm2. While perfect linear recombination is observed across four orders of magnitude, an additional radiative recombination mechanism emerges at an excitation density of 1 μ J/cm2 per pulse at 390 nm excitation and increases the external quantum efficiency. The time constant of this process is ~20-40 ps. It is ascribed to stimulated emission. No hint to any non-linear non-radiative processes such as Auger recombination is observed. Thermal effects, however, still set limits. This is encouraging news for PbS:Glass as potential laser material. © 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Bock M.,Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy | Skibina J.,Chernyshevsky Saratov State University | Fischer D.,Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy | Bretschneider M.,Institute for Scientific Instruments GmbH | And 5 more authors.
Laser and Photonics Reviews | Year: 2013

A novel fiber technology is presented that enables the transmission of 200 nm wide spectra over meter-long distances with minimal temporal reshaping and acceptable losses down to about 3 dB/m. Delivery of a 10 fs pulse over nearly meter distance is experimentally demonstrated, which sets a new standard for the fiber-based delivery of few-cycle pulses. Numerical simulations provide insight into the unique guiding mechanism in the novel hollow-core fiber technology, enabling dispersion parameters that are within an order of magnitude of those available in free space propagation. A novel fiber technology is presented that enables the transmission of 200 nm wide spectra over meter-long distances with minimal temporal reshaping and acceptable losses down to about 3 dB/m. Delivery of a 10 fs pulse over nearly meter distance is experimentally demonstrated, which sets a new standard for the fiber-based delivery of few-cycle pulses. Numerical simulations provide insight into the unique guiding mechanism in the novel hollow-core fiber technology, enabling dispersion parameters that are within an order of magnitude of those available in free space propagation. © 2013 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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