Multilayer Optical Data Storage using Co-extruded Films
Cory W. Christenson, Kenneth D. Singer and Eric Baer
As the generation of digital data rapidly exceeds storage capacity, new methods for storing data are urgently needed. At the same time, it is being recognized that data archiving is vastly underutilized. We report here on a new approach to archival and nearline data storage using a multilayer polymer film, consisting of dozens of active layers made using a low-cost, scalable roll-to-roll co-extrusion process. The imparted data can last for decades, and the many writable layers means terabyte scale capacities can be achieved. The film consists of alternating layers of a transparent polymer and a polymer doped with an organic fluorescent dye, which is written by photobleaching using a CW Blu-ray laser. Images have been written in 23 layers with little observable cross-talk because of the physical layering scheme. In addition, we have explored the photophysics of the dye response, which reveal a nonlinear writing process for short duration writing pulses suggesting the possibility of even lower crosstalk and sub-diffraction limit writing. The mechanism of the non-linear response is also discussed.
Keywords: Data storage, fluorescence, photobleaching, extrusion, organic, polymer