Femtosecond laser ablation based on two-photon absorption was employed to cut ZnO nanorods into uniform ZnO nanoparticles of deep subwavelength size. The fabricated ZnO nanoparticles possess a shorter mean transport length for photons at the emission wavelength and a much smaller scattering cross section at the pump wavelength, leading to highly efficient two-photon-pumped random lasing with a ...

Diamond, with its exceptionally high optical nuclear potential and low absorption cross-section, is a unique material for a series of applications in VCN (very cold neutron) physics and techniques. In particular, powder of diamond nanoparticles provides the best reflector for neutrons in the complete VCN energy range. It allowed also the first observation of quasi-specular reflection of cold ne...

We present a numerical integration scheme for the propagation of particles/rays within continuous, inhomogeneous media, represented as discrete scalar fields. Our method aims at the calculation of energy distribution, where the initial energy is evenly distributed over a large number of particles, which are traced through the medium. While traversing the particles interact with the medium by me...

We study the absorption of massive spin-half particles by a small Schwarzschild black hole by numerically solving the single-particle Dirac equation in Painlevé–Gullstrand coordinates. We calculate the absorption cross section σ(E) for a range of gravitational couplings Mm/mP 2 and incident particle energies E. At high couplings, where the Schwarzschild radius RS is much greater than the wavele...

It has recently been shown that the equation of motion of a massless scalar field in the background of some specific p branes can be reduced to a modified Mathieu equation. In the following the absorption rate of the scalar by a D3 brane in ten dimensions is calculated in terms of modified Mathieu functions of the first kind, using standard Mathieu coefficients. The relation of the latter to Do...

We study scalar field perturbations on the background of non-supersymmetric black rings and of supersymmetric black rings. In the infinite-radius limit of these geometries, we are able to separate the wave equation, and to study wave phenomena in its vicinities. In this limit, we show that (i) the non-supersymmetric case is stable against scalar field perturbations, (ii) the low energy absorpti...

On the basis of our previous work on vinyl-triphenylamine derived DNA fluorophores we explored the structure space around this core by coupling it to diverse cationic, anionic and zwitterionic groups in the aim of targeting different classes of biomolecules. In parallel core modifications were performed to optimize the photophysical properties (quantum yield, two-photon absorption). The resulti...

In the vapor phase a solvent-free spectroscopic analysis of dye molecules is applicable [1-3]. For some dye vapors laser action was achieved [1-3]. The dye vapor pressure rises approximately exponentially with temperature. Reasonable vapor pressures (p around 100 Pa = 1 mbar) are obtained for many non-ionic dyes in a temperature region between 200 and 400 °C without considerable thermal decompo...

Absolute absorption cross-section and photolysis rate of I2 A. Saiz-Lopez, R. W. Saunders, D. M. Joseph, S. H. Ashworth, and J. M. C. Plane School of Environmental Sciences, University of East Anglia, Norwich, UK School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich, UK Received: 23 February 2004 – Accepted: 8 April 2004 – Published: 5 May 2004 Correspondence to: J. M. C....

A thorough investigation of the emission and absorption spectra of the (3F4,3H6) band in thulium doped silica fibers has been performed. All the basic parameters of thulium in silica have been extracted with the purpose of further analysis in laser and amplifier simulations. The experimental methods used to obtain the scaled cross sections have been carefully selected in order to avoid problems...