Optical Properties of Neodymium Doped Magnesium Zinc Sulfo- Phopshate Glass: Impact of Gold Nanoparticles Inclusion

Gold (Au) nanoparticles (NPs) incorporated in magnesium zinc sulfo-phosphate glass with the molar composition of (58.5P_2O_5–20MgO–20ZnSO_4–1.5Nd_2O_3–xAu NPs (where x = 0.0, 0.1, 0.2, 0.3, and 0.4 mol%) were prepared via melt quench technique. The effect of Au NPs as incorporated in Nd^3+ doped glasses were studied using X‒ray diffraction (XRD), High Resolution-Transmission Electron Microscope (HR‒TEM), UV‒Visible-NIR absorption spectrometer and photoluminescence spectrometer. The amorphous nature of glass is confirmed via XRD measurements and existence of Au NPs inside the glass is reveal by HR-EM. The typical absorption bands of Nd^3+ are attained which positioned around 352, 430, 459, 474, 512, 525, 581, 626, 682, 744, 801and 875 nm. Up-conversion (UC) photoluminescence (PL) demonstrated six prominent emission bands located around 420, 445, 460, 484, 515 and 545 nm corresponding transition 2P_1/2--> 4I_9/2, 2D_5/2-->4I_11/2, 2P_1/2-->4I_11/2, 2D_5/2-->4I_13/2, 2K_15/2,4G_7/2-->4I_11/2,4I_9/2 and 2D_5/2-->4I_15/2 respectively. Glass containing 0.1 mol% of Au NPs shows utmost PL enhancement and the emission decrease beyond 0.1 mol% of Au NPs depicts re-absorption of SPR and increase of non-radiative channel. The improvement of PL intensity attributed to local field effect of Au NPs that altered the environment in proximity Nd^3+ ions. The proposed glass could be potential for improvement of solid state laser design.