Broadband telecommunication wavelength emission in Yb^3+-Er^3+-Tm^3+ co-doped nano-glassceramics

Transparent Yb(3+), Er(3+) and Tm(3+) co-doped nano-glass-ceramics 3(SiO(2)2)9(AlO(1.5))31.5(CdF(2))18.5(PbF(2))5.5(ZnF(2)):3.5(Yb-Er-TmF(3)), mol%, have been prepared where co-dopants mostly partition in nano-crystals Pb(1-x) (Yb(3+),Er(3+),Tm(3+))(x)F(2+x) embedded in the glass network. The Yb(3+) ensures high absorption at 980 nm telecommunication pump wavelength and further phonon-mediated energy transfer to Er(3+) and Tm(3+) co-dopants. Er(3+) and Tm(3+) radiate overlapping emission bands from their lowest energy levels, with similar lifetime of about 9 ms, which cover the range between 1.50 to 1.70 mum. The lifetime of all higher levels of Er(3+) and Tm(3+) dopants is shorter than 70 mus due to short inter-dopant distances in the nano-crystals resulting in fast energy transfer to their lowest levels.