Ultrafast emission under two‐photon excitation of biexcitons in CuCl quantum dots

Abstract

Abstract Time‐resolved photoluminescence spectra of biexcitons confined in CuCl quantum dots have been measured by means of an optical Kerr‐gate method. When the biexcitons are generated by resonant two‐photon excitation, a new ultrashort photoluminescence is observed. This result indicates that the resonant two‐photon excitation of the biexcitons induces a new transition process with a large optical nonlinearity which is characteristic for the direct generation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)