Nanostructure surface relief profiles for high-density optical data storage

A new optical data storage structure is proposed that utilizes surface relief profiles at sub-wavelength scales to distinguish memory states in a read-only memory system. Groupings of power sensors directly beneath the features read light transmitted through the structure from above. These are used to distinguish states from one another, where different surface profiles lead to different states. Two-dimensional simulations are performed using the finite-difference time-domain (FDTD) method to optimize parameters of the system, and to determine the data capacity and density of optimal systems. Two optimal systems are studied in detail: one intended as a polymer construction, the other as silicon. Techniques are developed to estimate capacity and density from subsets of simulations. Simulations estimate that densities of 3.17 GBits/cm2 are possible with this type of system.