Photorefractive material response to short pulse illuminations

Abstract

Photoconduction and hologram recording in a Bi <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</inf> SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</inf> single crystal are studied from both theoretical and experimental points of view in the case of short pulse excitations. An approach taking into account two kinds of acceptor centers explains the charge transport processes in the case of both pulsed and continuous illuminations. A nanosecond temporal resolution allows us to access a time domain that is not normally considered, and on this time scale, the electron migration velocity is governed by the intrinsic mobility, which we have estimated to he greater than 3.2 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V . s. Using this value, our theoretical developments explain the fast beam coupling phenomenon that we have experimentally observed.