Holographic display system with enhanced viewing angle using boundary folding mirrors

In digital holographic 3D display, the limited size of the spatial light modulator (SLM) restricts the viewing angle of reconstructed images. Tiling multiple SLMs can improve the viewing angle but this method brings much increased cost and takes up large space. In this paper, we propose using boundary folding mirrors to expand the viewing angle of holographic display system. The size of the SLM is equivalently expanded since additional virtual regions effectively exist in the mirror folded regions. Superior to the multiple SLMs method, the proposed method takes up less space and decreases the cost since only one SLM and several mirrors are needed in our system. Compared with the holographic display method using a single SLM, the experiments demonstrate that the proposed method can obviously expand the viewing angle.