ULTRAFAST AIR-OPTICAL SWITCH USING COMPLEX REFRACTIVE-INDEX CHANGES OF THIN-FILMS CONTAINING PHOTOCHROMIC DYE

An all-optical switch has been proposed based on photoinduced changes of an imaginary part of complex refractive index in a composite thin f ilm made by silver and polymer thin films containing photochromic dye. Very fast switching on and switching off of a reading beam was demons trated at the incident angle of guided wave mode using a photochromic spiropyran-doped polystyrene thin film and a ns pulsed laser as a writ ing beam. These responses were caused by the changes of an extinction coefficient due to photochromism. No applied power was required to hol d the switched state. (C) 1997 American Institute of Physics.