All organic photoactive liquid crystalline materials for 3D optical data storage – 3D-ODS

The storage and preservation of large amounts of data (Big Data) constitute a crucial technological challenge linked to the evolution of data processing, which requires the development of innovative molecular materials. The present multidisciplinary 3 Dimensions-Optical Data Storage (3D-ODS) project is dedicated to the design and in depth investigation of innovative and stimulable photoactive thin films which will allow high-resolution and high-density three dimension information encoding at the supramolecular level. Original chromophores combining in one single molecule several synergetic properties such as two-photon absorption, photodimerization, chirality to ensure strong 2nd order nonlinear response will be developed. Additional liquid crystalline properties will be exploited to generate really attractive stimuli-responsive, well-organized, anisotropic, soft and malleable materials. Photophysical studies and writing/reading process in the bulk (3D) will be investigated by laser based methods.

The objectives of the project will be the design and the characterization of the liquid crystalline material and studies of linear and non-linear photophysical properties of the Non Linear Optic chromophore (NLO-phore) coupled to two-photon dimerizable molecular entities. Our main objective will be devoted to the preparation of thin films from these original chromophores and their use for laser pin-pointed 3D data storage. The use of non-linearly optically active chromophores will allow writing at the surface of the thin films but also in depth. In this way, several levels of writing will be accessible and more information will be stored per surface area. Despite, the richness of this approach, a limited number of attempts have been done up to now to directly incorporate non-linear optical properties onto mesogens. This approach is an elegant alternative to the classical optical technics which should improve the data storage capability inside flexible thin film.

This collaborative project (PRC) involves two French partners (ANR funding) and one international partner (own funds): Dr. Franck Camerel (CNRS research fellow) from the Institute of Chemical Sciences of Rennes (UMR 6226, Rennes 1 University, CNRS, France), Dr. Jean-Pierre Malval (Associate Professor) from the Materials Science Institute of Mulhouse (IS2M, UMR 7361, CNRS, Mulhouse University, France) and Pr. Koen Clays from the Division of the Molecular Imaging and Photonics (KU Leuven, Belgium).

We plan i) the design of multifunctional all organic photoactive liquid crystalline molecules, combining NLO properties and two-photon dimerization, ii) the characterization of the linear and non-linear optical properties of these molecules in solution and in solid state, iii) their processing as Second Harmonic Generation (SHG) active thin films and iv) the use of pulsed laser based methods to induce data encoding of the photodimerizable units in 2D and 3D inside the supramolecular organization by two-photon absorption. The work program includes activities consistent with the Partnership's over all aims and objectives, and covers the whole period of 48 months.