Energy transfer processes in (Yb3+, Dy3+) and (Tm3+, Dy3+) codoped LiYF4 and KY3F10 single crystals

Dy3+ doped LiYF4 and KY3F10 crystals exhibit mid-IR emissions around 1.7 μm and more particularly around 2.9 μm. Codoping with Yb3+ or Tm3+ ions allows diode laser pumping around 970 and 780 nm and study of spectroscopic properties and energy transfer processes shows that 2.9 μm laser emission should be readily obtained under reasonable pump power.