Time-resolved spectra of excited-state absorption in Er3+ doped YAlO3

A pump- and probe-beam technique is used for measuring time-resolved excited-state absorption (ESA) and stimulated-emission (SE) spectra of Er³⁺ doped YAlO₃. The Er³⁺⁴I_15/2 ⁴F_7/2 transition of the sample is excited at 488 nm by an excimer laser pumped dye laser. The ESA and SE of broadband xenon flashlamp light is monitored between 300 and 860 nm by an optical multichannel analyzer (OMA). The analysis of the experimental results provides information on the effective cross sections _ESA and _SE originating from several levels and on the populations of these levels. To our knowledge this represents the first detailed investigation of time-resolved ESA and SE over a broad spectral range in rare-earth doped materials.