Upconversion Luminescence Properties of a LiNb0.3Ta0.7O3:Er3+,Yb3+ Ceramic

A co-doped LiNb_0.3Ta_0.7O₃:Er³⁺,Yb³⁺ ceramic was prepared by a high temperature solid state procedure. Under the excitation of 980 nm laser radiation, intense 660 nm red light and 550 nm green light emissions corresponding to the ⁴F_9/2→⁴I_15/2 and ²H_11/2/⁴S_3/2→⁴I_15/2 transitions of Er³⁺ were observed. The change of Yb³⁺ concentration has a more significant influence on luminous intensity than the Er³⁺ concentration. The emission of red and green lights is attributed to a two-photon process. The upconversion luminescence mechanisms were analyzed in detail.