Third order nonlinear optical absorption studies of Cr3+ doped PbWO4 nanostructures

Abstract

We report the synthesis of Cr3+ doped PbWO4 nanoparticles with different concentration of Cr3+ through chemical method. The structural, morphological and optical characterization was studied through X-ray diffraction (XRD), Raman, UV–Visible spectra, Photoluminescence, X-ray photo electron spectroscopy (XPS) and Transmission electron Microscopy (HR-TEM). The XRD patterns revealed the tetragonal phase of stolzite and the peaks are highly crystalline structure with no segregation of Cr3+. UV–Vis absorption spectra reveal that the shift of absorption band edge towards higher wavelength upon doping of Cr3+ions. The average particle size of the nanostructure as revealed by the TEM image lies around 47 nm. Third order nonlinearity of Cr3+ doped PbWO4 nanoparticles were analysed by the standard Z-scan technique using 532 nm Nd: YAG laser. The observed nonlinear absorption (NLA) and nonlinear refraction (NLR) behavior is caused by thermal nonlinear effects due to localized heating. Experimental results have demonstrated that an increase in optical nonlinearity occurs with higher Cr3+ concentrations. Based on the observed nonlinearity it is suggested that the synthesized nanostructures could be used in various optical device applications.