Roll‐to‐Roll Fabrication of Multilayer Films for High Capacity Optical Data Storage

Optical data storage (ODS) has led to transformative advances in information storage and distribution technology. Conventional two-dimensional ODS media have allowed storage capacities necessary for high-defi nition video. The capacity is limited, however, by the size of the disk and the number of layers that can be addressed using highly scattering phase-change materials employed in these media. [ 1 ] Here we report on a co-extrusion process for fabricating roll-to-roll multilayer (ML) fi lms for high-density ODS. This process can easily produce a continuous, complete storage medium hundreds of meters in length and meters in width, ready for fabrication into the standard 120 mm diameter disk or a variety of other potential formats, with total writable areas suffi cient for terabyte (TB) to petabyte (PB)-scale capacity. The co-extrusion process is also low-cost and far simpler than current manufacturing approaches, such as spin-coating [ 2 , 3 ] and lamination. [ 4–6 ] We demonstrate data storage in 23 layers of a 78 μ m thick ML fi lm using a continuous-wave Blu-Ray (BR) laser by fl uorescence (FL) quenching of an organic dye. The areal density is found to be similar to that of commercial disks, and the small layer spacing allowed by a FL-based scheme leads to a bit density of 1.2 × 10 12 cm − 3 . Given the mechanism and high axial density, the cross-talk during writing is also examined. The approach is generic so that materials already developed for high-density ODS can be exploited for innovations including “cloud”-scale data storage. Commercial ODS disks are made by fi rst injection molding of the thick, plastic substrate. The refl ective and active layers are added by a combination of sputtering and spin-coating. [ 1 ] For simple read/write systems based on a bit-wise one-photon write scheme, a multilayer architecture would require a multiplicity of steps with the current manufacturing processes. Several organic dye/polymer schemes suitable for three-dimensional