Abstract

THz signals emitted from semiconductor superlattices after optical excitation provide a sensitive monitor for intraband dynamics. Recent measurements indicate that for resonant excitation in the vicinity of the energetically lowest exciton the THz response shows excitonic signatures for times much longer than T_2,inter, T_2,inter being the interband dephasing time.¹ It has been shown previously² that a description based on the concept of dynamics controlled truncation (DCT) predicts oscillations of excitonic origin for times determined by the intraband dephasing time T_2,inter, which can be considerably longer than T_2,inter/2.

© 1997 Optical Society of America