An efficient synthesis algorithm for wide-viewing full-color depthmap computer-generated holograms is proposed. We develop a precise computational algorithm integrating wave-optic geometry-mapping, color-matching, and noise-filtering to multiplex multiview elementary computer-generated holograms (CGHs) into a single high-definition CGH without three-dimensional perspective distortion or color dispersion. Computational parallelism is exploited to achieve significant computational efficiency improvement in the production throughput of full-color wide-viewing angle CGHs. The proposed algorithm is verified through the full-color binary hologram reconstruction experiments utilizing an off-axis R·G·B simultaneous illumination method, which suggests the feasibility of the full-color sub-wavelength binary spatial light modulator technology.
We propose a compressive self-interference incoherent digital holography (SIDH) with a geometric phase metalens for section-wise holographic object reconstruction. We specify the details of the SIDH with a geometric phase metalens design that covers the visible wavelength band, analyze a spatial distortion problem in the SIDH and address a process of a compressive holographic section-wise reconstruction with analytic spatial calibration. The metalens allows us to realize a compressive SIDH system in the visible wavelength band using an image sensor with relatively low bandwidth. The operation of the proposed compressive SIDH is verified through numerical simulations.
In the depth-map computer-generated hologram (CGH), inter-layer edge artifacts are observed in the discontinuous edges of section-wise depth-map objects. CGH synthesis, utilizing the hybrid smoothing method of silhouette masking and edge-apodization, alleviates unwanted inter-layer edge artifacts. The proposed method achieves improved de-artifact filtering that generates holographic images closer to the ground truth image of the depth-map object unattainable by the conventional CGH synthesis method.
Complex spatial light modulation, which can simultaneously control the amplitude and phase of light, is an essential optical technology for holographic display. We propose a twisted nematic liquid crystal (TNLC) mode with an in-cell type embedded geometric phase (GP) plate for full-color complex spatial light modulation. The proposed architecture provides an achromatic full-color complex light modulation capability in the far-field plane. The feasibility and working characteristics of the design are validated through numerical simulation.
We present the Fourier coupled modal method (FCMM) as a solution for large-scale photonic structure analysis, emphasizing its inherent parallelism, facilitated by spatial partitioning and Fourier modal field computation. The parallelism of the FCMM is achieved by integrating the coupled mode theory (CMT) within the Fourier modal method (FMM). The proposed numerical framework of the FCMM is detailed and validated through a comparative study with the conventional FMM.
This paper investigates the submicron scale color filter design in the high-definition computer-generated hologram (HD-CGH). It is addressed that single pixel structural coloration is essential for full-color wide-viewing angle HD-CGH because the conventional RGB color stripe filter degrades HD-CGH image quality due to low misalignment tolerance. Considering that a submicron scale slit or hole with metallic mirror sidewalls can operate as a single pixel color filter. We propose a design of single pixel RGB plasmonic color filter (PCF) and present the feasibility of applying the proposed single pixel RGB PCF to high-definition HD-CGHs. Based on the RGB PCF platform, a 1.1 mu mx 1.1 mu m RGB PCF is designed and the corresponding optical characteristics of the full-color HD-CGH are analyzed. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement