Improving viewing region of 4f optical system for holographic displays

A 4f optical system with a single-sideband filter has been used for electronic holographic displays in order to obtain a reconstructed image without a conjugate image and zero-order diffraction light. However, the viewing region is inclined, and the viewing region in which an entire reconstructed image can be viewed is limited. In the present study, one of the Fourier transform lenses constituting the 4f optical system is shifted to correct the viewing region inclination. Moreover, a screen lens is added in the image plane of the 4f optical system to maximize the viewing region. The inclination of the viewing region can also be corrected by shifting the screen lens instead of shifting the Fourier transform lens. Experimental verifications of these corrections are described.