Holographic Investigation of Azobenzene-Containing Low-Molecular-Weight Compounds Von der Universität Bayreuth zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigte Abhandlung von Hubert Audorff geboren in Weiden in der Oberpfalz 1. Gutachter: Prof. Dr. Lothar Kador 2. Gutachter: Prof. Dr. Werner Köhler Tag der Einreichung: 15.12.2010 Tag des Kolloquiums: 16.02.2011 I Table of Contents 1 Introduction................................................................................... 1 1.1 Analog data storage ................................. 1 1.2 Digital data storage ................................... 1 1.3 Holographic data storage ......................... 3 1.3.1 Photorefractives .................................. 4 1.3.2 Photopolymers .................................... 4 1.3.3 Azobenzene-containing materials ...... 5 1.4 Aim of the thesis ....................................... 6 1.5 Outline ...................................................... 7 2 Basic theory .................................................. 9 2.1 Holography ............... 9 2.2 phically induced volume gratings ............................... 10 2.2.1 Writing and reading of holograms with plane waves ........ 10 2.2.2 Diffraction off thin holographic gratings ............................ 14 2.2.3 Diffraction off thick holographic gratings ........................... 15 2.2.4 Holograms of objects .......