Rewritable full-color computer-generated holograms based on color-selective diffractive optical components including phase-change materials

Abstract

We propose rewritable full-color computer-generated holograms (CGHs) based on color-selective diffraction using the diffractive optical component with the resonant characteristic. The structure includes an ultrathin layer of phase-change material Ge₂Sb₂Te₅ (GST) on which a spatial binary pattern of amorphous and crystalline states can be recorded. The CGH patterns can be easily erased and rewritten by the pulsed ultraviolet laser writing technique owing to the thermally reconfigurable characteristic of GST. We experimentally demonstrate that the fabricated CGH, having a fine pixel pitch of 2 μm and a size of 32.8 × 32.8 mm², reconstructs the three-dimensional holographic images. In addition, the feasibility of the rewritable property is verified by erasing and rewriting part of the CGH.