Up-conversion luminescence of Y2O3: Yb, Er under 1.55 μm excitation

This study explores a new method to achieve highly efficient red up-conversion luminescence by using Y2O3: Yb, Er pumping with a 1550 nm laser diode (Y2O3: Yb, Er@1550 nm). The strongest red emission, with a peak situated at 660 nm, can be assigned to Er3+ ion 4I9/2→4I15/2 transition. The radiation brightness of Y2O3: Yb, Er@1550 nm is comparable to that of Y2O3: Yb, Er under an equivalent 980 nm pumping density (Y2O3: Yb, Er@980 nm). Y2O3: Yb, Er@1550 nm presents a very weak green emission as compared with that of Y2O3: Yb, Er@980 nm. Consequently, Y2O3: Yb, Er@1550 nm exhibits much better color purity and excellent color stability with increasing pumping power.