Threshold characteristics cavityless lasing in composites with agglomerated metal and dielectric nanoparticles

The paper presents results of experimental studies of the threshold characteristics of lasing in thin layers (20 microns) of a solution of rhodamine 6G with agglomerates of metal and dielectric nanoparticles. The maximum decrease in the lasing threshold was more than two orders for a wide range of changes in the concentration of metal agglomerates. For dielectric nanoparticle agglomerates range of maximum lowering of the threshold is 5 times lower. This is due to different mechanisms of formation of lasing in these environments.Comparing the efficiency of lasing in layers with metal agglomerates proves on expediency using them to create a low threshold microlasers

Spectral shaping of lasing active medium with agglomerated nanoparticles of metals and dielectrics

In this paper presented a series of experiments determine the spectral characteristics of random lasing in lasers with agglomerated nanoparticles metals and dielectrics. The data allowed us to establish that, in the active heterogeneous environment, there are various gain effects of lasing the impact of which is determined nanoparticles concentration

The catalytic reduction of NO by H-2 on Ru(0001): Observation of NHads species

Adsorption of NO and the reaction between NO and H-2 were investigated on the Ru(0001) surface by X-ray photoelectron spectroscopy (XPS). Surface composition was measured after NO adsorption and after the selective catalytic reduction of nitric oxide with hydrogen in steady-state conditions at 320 K and 390 K in a 30:1 mixture of H-2 and NO (total pressure = 10(-4) mbar). After steady-state NO reduction, molecularly adsorbed NO in both the linear on-top and threefold coordinations, NHads and N-ads species were identified by XPS. The coverage of the NHads and N-ads species was higher after the reaction at 390 K than the corresponding values at 320 K Strong destabilisation of N-ads by O-ads was detected. A possible reaction mechanism is discussed. (c) 2005 Elsevier B.V. All rights reserved