In this work, spectral properties of (pyromethane 580) PM 580 laser dye were studied and study the effect of addition Au: Ag Nanoparticles .In this study, studied the spectral properties of the liquid dye (pyromethane 580) PM 580 dissolved in ethanol solvent with different concentrations (1x10-3 , 5x10-4 , 1x10-4 , 5x10-5 , 1x10-5 , 1x10-6 ) M and the ideal concentration was chosen at 1x10-6 M. Also, nanoparticles were prepared from the noble metals (gold and silver) (Au: Ag) NPs immersed in 3 ml of polyvinyl alcohol (PVA) using a pulsed laser Nd-YAG with wavelengths (532 nm) with a number of 500 pulses and different energy (400, 600, 800, 1000) mJ. The spectral and structural properties of the mixture (laser dye and nanoparticles) were also studied. The results of the spectral properties of the dye solution showed that the peak of the absorption spectrum and the peak of the fluorescence spectrum of the liquid dye shift towards the shorter wavelengths (blue shift) when the concentration decreases, while the relative intensity decreases with the decrease in concentration While the fluorescence spectra were increased when the concentration was decreased, Observed by varying amount of Au: Ag NPs, the intensity of absorption and fluorescence are increasing with increasing this amount

Nanoparticles; Pyrromethene 580 dye; quantum yield; Absorpence