Enhanced and Stable Upconverted White-light Emission in Ho(3+)/Yb(3+)/Tm(3+)-doped LiNbO(3) Single Crystal via Mg(2+) Ion Doping

A strategy to enhance the upconversion white-light intensity via Mg(2+) ion doping was demonstrated in Ho(3+)/Yb(3+)/Tm(3+)/LiNbO(3) single crystal. It is found Mg(2+) ion doping affects the crystal field symmetry around RE(3+) ions and enhance the upconversion emission intensity. Bright white-light is obtained when the Mg(2+) ion concentration is 0.5 mol% in the melt. And the CIE coordinates are hardly changed with Mg(2+) ion doping. In addition, the upconversion mechanism is discussed in detail. It is observed the longer lifetimes of intermediate levels result in the lower upconversion photon numbers, which are beneficial to the upconversion process. Therefore, Mg(2+) ion doped Ho(3+)/Yb(3+)/Tm(3+)/LiNbO(3) single crystals would have potential applications in stable white-light devices and photoelectric instruments.