Multi-layered optical storage with nonlinear read/write

A new concept of three-dimensional (3D) optical storage is proposed based on a multi-layered thin-film structure and a nonlinear optical (NLO) read/write process. Theoretical analysis of the device indicates that a 20-fold increase in total volume density can be expected without any compensating primary spherical aberration, owing to the lateral superresolution and the multi-layer structure in the vertical direction. © 1995, Japan Society of Applied Physics. All rights reserved.