Photoluminescence characterisation of Er~3+/Yb~3+ co- implanted alumina (Al_2O_3) thin films and sapphire crystals

摘要

Successful incorporation of both erbium and ytterbium in alumina by ion implantation is reported. Some evidence for indirect pumping of erbium through the transfer of energy from ytterbium has been observed. Both plasma-enhanced CVD deposited alurnina thin films and sapphire~3+ concentrations ranged from 2.4 At/100 to 8 At/100 and from 0.4 At/100 to 0.8 At/100, respectively. The samples show strong, broad, room-temperature photoluminescence at λ = 1.53μm corresponding to the intra-4f transitions between the ~4I_13/2, (first excited) and the ~4I_15/2, (ground) state of Er~3+. The full width at half maximum of the emission spectrum is as high as 67nm for the Al_2O_3 thin films; for the sapphire crystals it is 45nm. The fluorescence lifetime of the samples has been measured to be as high as 4.2ms at 50mW pump power.