Optical properties of Sm3+-doped CaF2 bismuth borate glasses

Sm3+-doped calcium fluoride bismuth borate glasses were prepared and characterized optically and the oscillator strengths and Judd-Ofelt parameters for the glass containing 1.5 mol% of Sm2O3 were calculated. Density and optical absorption, transmission and the emission spectra were measured. The values of Judd-Ofelt parameters suggested an increase in the degree of asymmetry the local ligand field at Sm3+ sites. The optical band gap energy, band tailing parameter and Urbach's energy were calculated for all glass samples. It was found that with increasing the concentration of Sm2O3 content the values of the optical band gap energy decrease whereas Urbach's energy increases. Absorption and excitation spectra indicate that commercial UV and blue laser diodes, blue and bluish-green LEDs and Ar+ optical laser are powerful excitation sources for Sm3+ visible fluorescence in the glass.