Analysis on angular field of view of holographic image dependent on hologram numerical aperture in holographic display

We investigate the angular field of view (AFOV) of a holographic image reconstructed from the digital Fresnel hologram in holographic display. The theoretical analysis clarifies that the AFOV of a holographic image is fundamentally determined by the hologram numerical aperture (HNA) other than a diffraction angle of pixel pitch of a pixelated modulator. This property is proved for various types of the digital holograms using a numerical simulation and optical experiments. The high-HNA hologram reconstructs the image with a high viewing angle, whereas the image contraction is inevitable due to the Nyquist sampling criterion in the hologram synthesis. We demonstrate the method for reconstructing the holographic image with a high viewing angle without image contraction.