Crafting 1.5 micrometer pixel pitch spatial light modulator using Ge2Sb2Te5 phase change material [Invited]

For this research, we have developed key technologies for a 1.5 μm pixel pitch spatial light modulator (SLM) using Ge2Sb2Te5 (GST) phase change material. To uniformly modulate each pixel, we designed a lateral pixel structure in which a heating current flows through a bottom indium tin oxide (ITO) layer. To check hologram reconstruction both after multilevel fabrication processes and before implementing full source and driver circuits, we fabricated an 8Kx2K hologram on the topology by changing the GST film’s phase using laser irradiation. To overcome the limitation of SLM size, we tested a physical tiling structure and found that flatness of tiled SLMs was the most important factor in the realization of holographic displays.