Successful Realization of Ultra-high-density Three-dimensional Dynamic Holographic Projection

Apr. 11, 2023

Recently, the research group of the Department of Optics and Optical Engineering of the University of Science and Technology of China(USTC) cooperated with domestic and foreign counterparts to propose a new method for ultra-high-density 3D holographic projection. The research team introduced light scattering into the three-dimensional holographic projection and overcame the two bottlenecks of the depth control of the traditional holographic projection technology, successfully realizing ultra-high-density three-dimensional dynamic holographic projection. By incorporating more depth information into holograms, the technology can more realistically reconstruct three-dimensional images for use in virtual reality and other applications. The research results have been recently published online in the international academic journal Optics.

It is always believed that optical holography is an ideal way to realize glasses-free 3D display, but the 3D holographic display of dynamically reconstructing realistic stereoscopic scenes has been facing the challenges, and the generation of real 3D holograms is the bottleneck problem. The real three-dimensional hologram involves the continuous and precise control of the depth information of the reconstructed object. The stronger the ability to control the depth information of the hologram, the higher the effective projection plane density, and the more realistic the image of the reconstructed object observed by the human eye. Dynamic holographic projection usually relies on spatial light modulators to modulate the light field wavefront to reconstruct object image information, and the currently generated holograms have very limited ability to control the depth. Furthermore, crosstalk between images on different depth planes further degrades the quality of holographic projections. Therefore, the low depth resolution of the projection planes and the large image crosstalk between planes become the two major limiting factors for generating realistic 3D holograms.

The researchers invented a technique called 3D scattering-assisted dynamic holography (3D-SDH). 3D-SDH uses multiple scattering of light to greatly increase the range of adjustable spatial frequency of the optical system, and develops speckle light field transmission properties to reduce the correlation of different depth plane light fields. Based on Fresnel holography, projection depth resolution is improved by more than 3 orders of magnitude, and at the same time, the crosstalk of images between different projection planes is greatly suppressed. In addition, the amplitude, phase, and polarization information of the light field are coupled during the scattering process, and the 3D-SDH further realizes a three-dimensional dynamic polarization holographic display through a single digital hologram.

According to the researchers, this technology can achieve high-density, low-crosstalk, and large-angle 3D dynamic holographic projection, and is expected to be applied in holographic microscopic imaging, stereoscopic display, projection lithography, information storage, optical micro-manipulation and other fields.