Generalized single-sideband computer-generated holography for high-quality three-dimensional display

Abstract

Computer-generated holograms (CGHs) can be used to reconstruct three-dimensional (3D) images without optical recording of the interference pattern. The conjugate image and zero-order beam have considerable influences on the optical reconstructions in computer-generated holographic display systems based on the amplitude spatial light modulators. Generalized single-sideband method is introduced for suppressing the unwanted terms in computer generated holography. Computer-generated holograms are calculated based on frequency filtering of the object wave, which redistributes the diffraction wave in spatial frequency domain for spectrum filtering during optical reconstruction. When the object wave on the hologram plane of the 3D scene is calculated, the single-sideband filter is addressed numerically after Fourier transform of the object wave. The filtered object wave can be calculated by inverse Fourier transform of the spectrum, and then it can be coded into the amplitude CGH. Different with the overlapped spatial frequency of the unfiltered CGH, the spectrum distributions of the object wave and the conjugate wave are located in the different sides of the spatial frequency domain with help of the single-sideband filter. By placing a single-sideband filter in Fourier plane, the conjugate image and the zero-order beam can be blocked during optical reconstruction. Since the proposed method directly processes the complex amplitude distribution of the object wave, it could be applied to various 3D CGH algorithms. Numerical simulations and optical experiments demonstrate that the proposed method is generally effective for different kinds of CGH algorithms to reconstruct quality three-dimensional scenes that are free of conjugate image and zero-order beam.