Multilayer optical data storage by fluorescence modulation using a CW laser

Optical data storage has been widely used in certain consumer applications owing to its passive and robust nature, but has failed to keep with larger industry data storage needs due to the lack of capacity. Many alternatives have been proposed and developed, such as 3D data storage using two-photon absorption that require complex and dangerous laser systems to localize the bits. In this paper, we present a method for localizing bits using a CW 405nm laser diode, in a multilayered polymer film. Data is stored by photobleaching a fluorescent dye, and the response of the material is nonlinear, despite the CW laser and absorption in the visible region. This is achieved using sub-μs pulses from the laser initiating a photothermal effect. This writing method, along with the inexpensive roll-to-roll method for making the disc, will allow for terabyte-scale optical discs using conventional commercial optics and lasers.