Infrared-to-visible upconversion flurescence of Er~(3+)/Yb~(3+)-codoped bismuthate glasses

摘要

Er~(3+)/Yb~(3+)-codoped bismuthate glasses for developing potential upconversion lasers have been fabricated and characterized.The optimal Yb~(3+) doping content was investigated in the glasses with different Yb~(3+)-Er~(3+) concentration ratios and the optimal Yb~(3+)-Er~(3+) concentration ratio is 5:1.Under 975 nm excitation,intense green and red emissions centered at 525,546 and 657 nm,corresponding to the transitions ~2H_(11/2)->~4I_(15/2),~4S_(3/2) -> ~I_(15/2) and ~4F_(9/2)->~4I_(15/2),respectively,were observed at room temperature.The quadratic dependence of the 525,546 and 657 nm emissions on excitation power indicates that a two-photon absorption process occurs under 975 nm excitation.