Large-size updatable optically addressed spatial light modulator (OASLM) based on ZnO nanoparticles for large-area holographic 3D displays

Optically addressed spatial light modulators (OASLMs) provide an appropriate solution for large-area and wide-viewing angle holographic displays because of the possibility of uploading holograms on it through tiling and with sub-micron diffraction feature sizes. A prototype with a large-size OASLM of 100 mm × 100 mm was fabricated using a solution-based deposition process for ZnO nanoparticles (NPs). ZnO NP-based OASLM is suitable for hologram tiling because of the extended charge carrier lifetime as a result of trap states in the ZnO NP layer annealed at a low temperature of 180°C, of which the activation energy was determined firstly by low-temperature measurements. Operating the ZnO NP OASLM in a DC driving mode was subsequently proposed, to utilize the extended charge carrier lifetime in the photosensor layer for temporary information storage. Finally, techniques to tile computer generated holograms (CGHs) spatially on a single OASLM were explored and evaluated, including the demonstration of simultaneous image replay from sequentially tiled two separate phase-only CGHs.