Synthetic holographic display for three - Dimensional optical see -Through augmented reality using a zero-order nulled grating

In this paper, a synthetic holographic display system for three-dimensional (3D) optical see-through augmented reality (AR) is proposed and implemented. The system is composed of a synthetic hologram reconstruction module and an optical see-through display module. The synthetic hologram reconstruction module utilizes a spatial light modulator (SLM) to present the virtual 3D image in the form of left and right stereo images, and the parallax angle between two stereo images can be enlarged by the zero-order nulled grating to meet the split angle requirement of normal stereoscopic vision. The virtual reconstructed scene and the real physical world will fuse together through the optical see-through display module. The zero-order nulled grating is specifically designed and fabricated, and its diffraction efficiency is measured. Furthermore, an experimental verification system for the proposed AR 3D display is presented. The experimental results prove that the proposed system can support virtual 3D display without crosstalk, and it is able to generate the realistic augmentation successfully.