Abstract

The phase relaxation of optically excited electronic states can be studied in fourwave mixing experiments where three excitation pulses at t = 0, t =t₂₁, and t = T, respectively, interact via the third-order polarization of the medium to generate a nonlinear signal whose intensity depends on the dephasing time T₂. For inhomogeneously broadened optical transitions the signal will be emitted as a time delayed photon echo pulse at t = T + t₂₁ provided the pulse duration is short compared with T₂. The echo amplitude decays as exp(−4t₂₁/T₂).¹

© 1990 Optical Society of America