LiNbO₃: Yb³⁺/Er³⁺/Tm³⁺; Power driven green to blue tunability

Abstract

Triple doped (Yb³⁺/Er³⁺/Tm³⁺) lithium niobate single crystals have been grown by the Czochralski method. Under selective Yb³⁺ excitation at 920 nm, bright visible up-converted luminescence is observed. It is found that the emission spectra of triple-doped system can be described as the superposition of Yb³⁺-to-Er³⁺ and Yb³⁺-to-Tm³⁺ energy transfer up-conversion, which exhibit differential power dependences. As a consequence, the triple doped system exhibits both power and concentration dependent emission spectra. It is possible to select the appropriate concentration of dopants in order to attain a very wide range of green to blue color tunability, within a single crystal, easily controlled by adjusting excitation power density.

Highlights