Optical data storage

In an era characterised by ever-increasing amounts of data being generated and stored electronically, the search for more efficient and compact methods of storing this data is of great importance. Despite the success of modern optical storage media, the density of bits in these materials is approaching the maximum achievable under the Rayleigh criterion; beyond this limit, diffraction effects will prevent individual bits from being optically resolved. One potential way of overcoming this difficulty is holographic data storage, which takes advantage of the storage material’s anisotropic refractive index to write three bits of data into each pixel, supporting very high information densities of up to 10¹⁴ bits cm^–2. The material sodium nitroprusside has been extensively studied for this purpose: its photorefractive properties arise from the existence of an optically accessible metastable state, rather than the Pockels effect, giving rise to unusual and potentially useful recording kinetics.

We are investigating related systems with metastable linkage isomers in an attempt to identify materials with potential uses in data storage. The principal experimental method is photocrystallography, but this is supplemented with other experimental techniques and DFT calculations.

Selected publications

• Anthony E. Phillips, Jacqueline M. Cole, Thierry d’Almeida, Kian Sing Low

  Ru–OSO Coordination Photogenerated at 100 K in Tetraammineaqua(sulfur dioxide)ruthenium(II) (±)-Camphorsulfonate

  Journal of Inorganic Chemistry 2012, 51, 3, 1204-06

• Anthony E. Phillips, Jacqueline M. Cole, Thierry d’Almeida, Kian Sing Low

  Effects of the reaction cavity on metastable optical excitation in ruthenium-sulfur dioxide complexes

  Physical Review B 2010, 82, 15, 155118

• Cole, Jacqueline M.

  Applications of Photocrystallography: a future perspective

  Zeitschrift für Kristallographie 2008, 223, 363–9