Photochromic monomeric materials for holography data storage

CHED 718

Rodolfo E. Camacho-Aguilera, rcamacho@gatech.edu, Department of Engineering, Materials Science & Engineering, Georgia Institute of Technology, Atlanta, GA 30332 and Eléna Ishow, ishow@ppsm.ens-cachan.fr, Department of Chemistry, Ecole Normale Supérieure de Cachan, Cachan, France.
Fabrication and analyses of new azo-based films have been explored for holographic data storage thanks to the bulk photo-assisted molecular migration shown by polymeric and monomeric azo materials. Some advantages presented by azo-functionalized materials rely on their photomigration leading to the reversible formation of surface relief gratings (SRG) with large refractive index or absorption modulation, and making them perfect candidates as rewritable supports. The designed bulky molecules present an amorphous phase whose glass transition temperature, way above room temperature, renders them thermally stable without risks of crystallization. Kinetics of the back thermal photoisomerization reaction monitored by UV-vis absorption spectroscopy, and holographic recording have been explored and evidenced the photoactive behavior and photomigration of the materials. The investigated photochromic monomeric materials have been proved to behave differently from photoactive polymers, and display faster photo-isomerization and migration, and stable SRG. Atomic force microscopy measurements of the illuminated thin films are performed parallely to scan the topography created in the different materials.