Abstract
The diffractive optical element (DOE) has the transformation function of wavefront, and its applications are forming or
homogenization of beam, and aberration correction, and so on. In this study, we evaluate possibility as storage
application of the DOE. The optical data storage using the DOE is thought of as a kind of holographic data storage
(HDS). In the HDS, digital data is recorded and read out as modulated 2-dimensional page data, instead of bit-by-bit
recording in conventional optical storages. Therefore, HDS actualize high data transfer rate. We design and optimize
phase distribution of the DOE using the iterative method with regularization. In the optimization process, we use
iterative Fourier transform algorithm (IFTA) that is known as Gerchberg–Saxton (GS) algorithm. At this time, the
regularization method is adopted to suppress minute oscillation of the diffraction pattern. Designed and optimized DOE
is fabricated by ultraviolet (UV) nanoimprinting technology. High productivity can be expected by adopting
nanoimprinting technology. DOEs are duplicated on the silicon (Si) substrate as reflection-type elements. Fabricated
DOE is evaluated in the experiment. We verify that DOE for optical data storage can be actualized through our approach.
