Spectroscopic properties of Er in Bi₂TeO₅ crystals

Abstract

The non-linear optical crystal Bi₂TeO₅ is a good host for several cations with segregation coefficients close to or larger than unity. Bi₂TeO₅: Er was the first rare earth doped crystal that was grown and studied. Eight Er³⁺ related transitions were identified in the absorption spectra, from the ⁴I_15/2 ground state. All the expected Stark components of the observed transitions were detectable at 10 K. Further splitting of the lines related to the different Bi sites occupied by Er. Excitation from higher Stark levels of the ground state was detected at 200 K and above. Erbium related luminescence was observed in the doped crystals after photo-excitation of the ⁴F_5/2 ⁴F_7/2 ²H_11/2 and ⁴S_3/2 levels.

Key Words:

• Bismuth tellurite
• Absorbtion spectra
• Luminescence