Resolution improvement method of holographic displays by using subframe holograms superposition and optical refraction actuator

Resolution is a critical indicator in holographic displays, but it is difficult to improve due to the low SBWP of present SLMs. In this paper, we proposed a new method to improve the resolution of holographic displays by analyzing the spatial correspondence between the hologram and the holographic image and considering the proper use of the subframe technology and superimposition in holographic displays. This method combines the subframe technology with holographic technology to obtain subframe holograms and synchronously controls subframe holograms and the optical refraction actuator to improve the resolution by superimposition. We performed numerical simulations on various subframe holograms to identify the optimal technique and designed a holographic system for optical experiments with the top three subframe holograms. Our method achieves higher resolution and reduced speckle noise with a simpler structure, offering new insights and advantages for SBWP-limited, volume-constrained, and compact holographic displays.