title: Dynamics of photo-induced terahertz optical activity in metal chiral gratings.
abstract: We investigated the dynamics of photo-induced optical activity of metal chiral gratings on an Si substrate for terahertz (THz) waves. We employed a new technique that enables optical-pump and THz-probe measurements via broadband THz spectroscopy at the microsecond time scale using a low-repetition-rate pump and a high-repetition-rate probe. We revealed that the THz optical activity decays as a result of the carrier diffusion effect because this optical activity is because of the presence of three-dimensional chiral structures of photo-carriers in the Si substrate.
authors.affiliation: Department of Applied Physics, The University of Tokyo, and Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan.
authors.forename: Natsuki
authors.initials: N
authors.lastname: Kanda
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Konishi
authors.forename: Makoto
authors.initials: M
authors.lastname: Kuwata-Gonokami