A method of diffraction calculation between tilted planes with variable sampling rates is proposed. The proposed method is based on the Fourier spectrum rotation from a tilted plane to a parallel plane. The nonuniform fast Fourier transformation (NUFFT) is used to calculate the nonuniform sampled Fourier spectrum on the tilted plane with variable sampling rates, which overcomes the sampling restriction of FFT in the conventional method. Both of the computer simulation and the optical experiment shows the feasibility of our method in calculating the hologram of polygon-based object with scalable size, which can be considered as an important application in the holographic three-dimensional display.

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A liquid crystal grating with high spatial frequency and equivalent capacitance configuration is proposed, where two layers of periodical ground electrodes are interlaced and aligned with the addressing electrodes. The equivalent capacitance configuration can reduce the fringing field effect efficiently owing to the generated electric field resisting the fringing field and redistributing the equivalent voltage exerting on the liquid crystal layer. The phase modulation depth and far-field diffraction patterns both for conventional and novel configurations were simulated. The results show that phase modulation is greatly enhanced and the maximum diffraction efficiency for a sinusoidal phase grating is 33.86%, which indicates that the equivalent capacitance configuration provides a good solution for suppressing the fringing field effect.

Waveguide holograms' diffraction properties include peak wavelength and diffraction efficiency, which play an important role in determining their display performance. Based on the record and reconstruction theory of reflection waveguide holograms, a novel experimental method for testing diffraction properties is introduced and analyzed in this paper, which uses a plano-convex lens optically contacted to the surface of the substrate plate of the waveguide hologram, so that the diffracted light beam can be easily detected. Then an experiment is implemented. The designed reconstruction wavelength of the test sample is 530 nm, and its diffraction efficiency is 100%. The experimental results are a peak wavelength of 527.7 nm and a diffraction efficiency of 94.1%. It is shown that the tested value corresponds well with the designed value.

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