Differential absorption measurements of Cr4+-doped forsterite under picosecond excitation

摘要

Polarized differential absorption spectra of Cr$+4$PLU$/- doped forsterite have been studied using a picosecond pump- probe technique. For pump beam and probe beam polarization parallel to the axis, an excited state absorption in the 450-800 nm region is observed and assigned to the $+3$/T$- 2$/$YLD$+3$/T$-1$/($+3$/P) transition of Cr$+4$PLU$/ ion. The lifetime of the $+3$/T$-1$/($+3$/F) state is estimated to be less than 15 ps.