Excited state absorption induced optical limiting behavior of pure, single, and co-doped copper oxide nanoparticles

Underneath nano pulsed green laser (Nd: YAG), nonlinear absorption and optical limiting behavior were analyzed using Z-scan technique for pure CuO, Ag, and Mn-doped CuO (single dopant), and Ag/Mn-doped CuO (co-dopant) nanoparticles intermediated from M. Oleifera leaf extract. X-ray diffraction pattern confirmed that the synthesized nanoparticles were in good crystalline nature with a monoclinic phase and the average crystallite size was estimated in the range of nanometer. FE-SEM analysis displayed that the pure CuO, Ag-doped CuO, and Ag/Mn-doped CuO appear as nanospheres whereas Mn-doped CuO forms themselves as nanorods. The existence of Cu, O, Ag, and Mn elements in synthesized nanoparticles was affirmed by an EDAX spectrum. FT-IR analysis confirms the presence of functional groups. In zeta potential analysis the negative (-ve) potential values -34.23 mV to -34.80 mV indicate the stability of the nanoparticles. The optical study revealed that the nanoparticles possess absorbance maxima in the UV region between 260 nm to 294 nm. The occurrence of a single ionized oxygen vacancy defect was affirmed by the photoluminescence studies. Z-scan studies with nano pulsed Nd: YAG lasers show all the samples exhibit two-photon absorption (2 PA) and optical limiting behavior. In contrast with pure and co-dopant materials (Ag/Mn-doped CuO), the dominant nonlinear absorption coefficients (0.90 x 10-10 m/W, & 0.98 x 10-10 m/W) and submissive values of optical limiting threshold (1.69 x 1012 W/m2 & 1.31 x 1012 W/m2) were found for single dopant materials (Ag & Mn-doped CuO). Thus single metal doped CuO finds potential application in the creation of laser safety devices against massive power nano pulsed green laser beams.