porous silicon (ps) samples have been prepared by electrochemical anodization of p-type silicon wafer by varying hf concentrations in the electrolytic solution. the structural, surface morphological, optical and surface composition analysis of the prepared samples were done by x-ray diffraction (xrd), scanning electron microscopy (sem), photoluminescence (pl) and fourier transform infrared (fti...

The cluster of galaxies A 1795 hosts a 46 kpc-long filament at its core, which is clearly visible in the light of Hα and X-ray emission. We present optical slit spectroscopy and deeper Chandra X-ray data of the filament. The optical spectra reveal that the the bulk of the filament is quiescent (with σ <130 kms ), although considerable velocity structure is apparent around the powerful radio sou...

The purpose of this research is to evaluate new materials as gain media for midinfrared (MIR) solid-state lasers. MIR lasers are of significant current interest for several applications including laser remote sensing of bio-chemical agents, medical surgery, fundamental spectroscopy, and biophotonics. In this project, Cobalt (Co) doped ZnSe windows and CdTe crystals were investigated as MIR lase...

This study describes a scanning time-resolved fluorescence spectroscopy (TRFS) system designed to continuously acquire fluorescence emission and to reconstruct fluorescence lifetime images (FLIM) from a luminal surface by using a catheter-based optical probe with rotary joint and pull-back device. The ability of the system to temporally and spectrally resolve the fluorescence emission from tiss...

We investigated the angular dependence of atomic and ionic debris from CO2 and YAG laser-produced tin plasmas. Several diagnostic techniques were employed for this study including a Faraday cup, witness plates and subsequent x-ray photoelectron spectroscopic analysis, optical emission spectroscopy etc. It was found that the debris emission from the Nd:YAG laser-produced plasmas fell sharply fro...

We report on the observation of fast hydrogen atoms in a capacitively coupled RF reactor by optical emission spectroscopy. For the analysis we use the prominent H emission line of atomic hydrogen in combination with other lines from molecular hydrogen and argon. Several characteristic emission structures can be identified. One of these structures is related to fast hydrogen atoms traveling from...

Emission spectroscopy is used to investigate the effect of inert gas mixing in nitrogen plasmas generated in inductively coupled plasma (ICP) and electron cyclotron resonance (ECR) plasma sources. Vacuum ultraviolet (VUV) emission of resonance lines is used to determine concentration of atomic nitrogen while electron temperature is obtained from optical emission spectra. It is found that electr...

Patterned metal films have been shown to possess unique optical properties resulting from the excitation of surface plasmon polaritons at the patterned metal surface. Here we demonstrate spectrally selective thermal emission from patterned steel substrates. The materials and processes used in this work were chosen for their potential scalability to large-area and low cost production of metal fi...