A systematic investigation into the excitonic properties of wurtzite ZnS nanowires (NWs) is presented. Under optical excitation, the ZnS NWs exhibit strong ultraviolet (UV) emission. Optical transition from free exciton A, free exciton B, and shallow level emission are observed and analyzed through power-dependent and temperature-dependent photoluminescence spectroscopy measurements performed f...

The optimum infusion timing and k-space ordering for obtaining gadolinium-enhanced three-dimensional MR angiograms was determined through computer modeling using temporal contrast characteristics obtained from patient gadolinium infusion data. The effects of bolus timing were evaluated by varying the relationship between peak intravascular gadolinium concentration and the time at which the cent...

Long-term stability of a laser system is crucially important for applications such as ultrafast laser spectroscopy. Unfortunately, this topic received little attention in novel pulse compression schemes. Through the ultra-stable beam pointing of the 50 kHz laser system, the long-term stability of nonlinear pulse compression (NPC) was measured for up to 17 hours at different peak powers in a fib...

We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as well as at elevated temperatures, utilizing a confocal microscope. The fluorescence peak wavelength...

The recent Spitzer detections of the 9.7μm Si–O silicate emission in type 1 AGNs provide support for the AGN unification scheme. The properties of the silicate dust are of key importance to understanding the physical, chemical and evolutionary properties of the obscuring dusty torus around AGNs. Compared to that of the Galactic interstellar medium (ISM), the 10μm silicate emission profile of ty...

Wepresent a detailed experimental and theoretical Raman investigation of quantum confinement and laser-induced local thermal effects on hydrogenated nanocrystalline silicon with different nanocrystal sizes (3.6–6.2nm). The local temperature was monitored by measuring the Stokes/anti-Stokes peak ratio with the laser power density range from ~120 to 960kW/cm. In combination with the three-dimensi...

The efficiency of a coherent VUV source at 125 nm, based on 2-photon resonant four-wave mixing in mercury vapor, has been enhanced by up to 2 orders of magnitude. This enhancement was obtained by locally heating a liquid Hg surface with a pulsed excimer laser, resulting in a high density vapor plume in which the nonlinear interaction occurred. Energies up to 5 μJ (1 kW peak power) have been ach...

Precursor effects of indium melting have been investigated by means of Mechanical Spectroscopy (MS) and High Temperature X-ray Diffraction (HT-XRD). MS tests evidenced a sharp drop of dynamic modulus in the temperature range between 418 K and 429 K (melting point). At 429 K, HT-XRD showed partial grain re-orientation, peak profile broadening, in particular in the lower part, and peak shift towa...

We examine properties of whispering gallery modes (WGMs) in a dielectric microsphere coated with a highrefractive-index layer. With an increase in layer thickness, the photonic field of a WGM moves near the sphere’s surface, while the peak in its radial distribution narrows, followed by backtracking and broadening. During these changes, the resonance frequency decreases. The radial compression ...

Pulsed UV lasers at the wavelengths of 374 and 280 nm are realized by cascaded second harmonic generation (SHG) and sum frequency generation (SFG) processes using a Nd:YAG laser at 1123 nm. The Nd:YAG laser is longitudinally pumped and passively Q-switched, and it has a high peak power of 3.2 kW. The UV peak powers at 280 and 374 nm are 100 and 310 W, with pulse lengths of 6 and 8 ns, respectiv...