Time-resolved nonlinear optical spectroscopy of Mn3+ ions in rare-earth hexagonal manganites RMnO3 (R = Sc, Y, Er) - art. no. 201103

A time-resolved. spectroscopic study of the third-order nonlinear optical r esponse of rare-earth hexagonal manganites RMnO3 (R=Sc, Y, Er) was performe d in the range of 1.45 to 1.62 eV nearby the first d-d transition in Mn3+ i ons. The nonlinearity was shown to result in a transient perturbation Delta epsilon(omega) of the dielectric permittivity tensor, whose antisymmetric part decays within less than 100 fs through the relaxation of excited elect rons. The symmetric part of Delta epsilon(omega) was found to depend upon t wo distinct relaxation processes with decay times of about 360 Ps and more than 70 ps, which were attributed to phonon thermalization and lattice cool ing, respectively.