title: Efficient two-photon light amplification by a coherent biexciton wave.
abstract: A reversible coupling between photon pair states and a long-lived, highly coherent biexciton wave in CuCl allows efficient phase-sensitive two-photon amplification or attenuation of ultrashort light pulses. We demonstrate a gain of 350 cm(-1) for a pump intensity of 1 MW/cm(2), nearly 2 orders of magnitude higher than that achievable with conventional parametric crystal amplifiers. We develop a theoretical model that describes this new type of parametric converter where the light pump is replaced by a coherent biexciton wave and show that it is well suited for the generation of entangled photons and the squeezing of an optical beam with ultrafast time gating.
authors.affiliation: Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Shimano
authors.forename: Yu P
authors.initials: YP
authors.lastname: Svirko
authors.forename: A
authors.initials: A
authors.lastname: Mysyrowicz
authors.forename: M
authors.initials: M
authors.lastname: Kuwata-Gonokami