| Summary: | The phenomenon of dichroism has been achieved in aluminophosphate glass via precipitation of plasmonic copper nanoparticles (NPs), and further revealed to enhance the orange-red emission of Sm3+ ions relevant to optical applications. The precursor amorphous material was synthesized by melt-quenching in ambient atmosphere. A subsequent heat treatment is shown to induce the precipitation of Cu NPs exhibiting distinct plasmonic behavior, and consequently manifest the dichroic effect wherein the material transmits blue light but scatters the red. Optical absorption and transmission electron microscopy analysis allow for a novel interpretation regarding the origin of the dichroic effect in copper nanocomposite glasses, namely an enhanced scattering due to plasmonic coupling between Cu NPs. The improved Sm3+ photoluminescence (PL) was achieved in an excitation-dependent fashion, manifested under non-resonant excitation conditions where divalent tin and monovalent copper centers can first absorb photons and subsequently participate in energy transfer to Sm3+ ions. Moreover, the PL enhancement is selective for Sm3+ emission transitions 4G5/2 → 6H9/2, 6H7/2 in resonance with the plasmonic band in the dichroic nanocomposite, thus suggesting that light scattering by Cu NPs plays an important role in the improved output. It is the first time to the author's knowledge that this type of effect is reported for copper and rare-earth co-doped glasses. Keywords: Glasses, Nanoparticles, Optical properties, Plasmonics, Rare earths
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