Femtosecond carrier relaxation in semiconductor-doped glasses

Abstract
Light induced changes of absorption in semiconductor‐doped glasses are studied on the femtosecond and picosecond time scale. Extremely rapid absorption recovery times of 200 fs are found when carriers are excited with large excess energy (500 meV) above the absorption edge of the semiconductor‐doped glasses. Excitation close to the band edge results in a slower absorption recovery with a time constant of τ≂100 ps.