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Holography is a promising avenue for high-quality displays without requiring bulky, complex optical systems. While recent work has demonstrated accurate hologram generation of 2D scenes, high-quality holographic projections of 3D scenes has been out of reach until now. Existing multiplane 3D holography approaches fail to model wavefronts in the presence of partial occlusion while holographic stereogram methods have to make a fundamental tradeoff between spatial and angular resolution. In addition, existing 3D holographic display methods rely on heuristic encoding of complex amplitude into phase-only pixels which results in holograms with severe artifacts. Fundamental limitations of the input representation, wavefront modeling, and optimization methods prohibit artifact-free 3D holographic projections in today’s displays. To lift these limitations, we introduce hogel-free holography which optimizes for true 3D holograms, supporting both depth- and view-dependent effects for the first time. Our approach overcomes the fundamental spatio-angular resolution tradeoff typical to stereogram approaches. Moreover, it avoids heuristic encoding schemes to achieve high image fidelity over a 3D volume. We validate that the proposed method achieves 10 dB PSNR improvement on simulated holographic reconstructions. We also validate our approach on an experimental prototype with accurate parallax and depth focus effects.
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Two-Way Pepper Ghost
Three-dimensional (3D) displays allow users to experience 2D images/videos in-depth illusions. Among the different 3D displays, we can distinguish the Pepper ghost illusion, which is a common approach to create a 3D hologram without goggles. In this work, we have upgraded the conventional Pepper ghost illusion, named as the two-way Pepper ghost tunnel, to create two simultaneous holograms. Contrary to the conventional Pepper ghost, the Pepper ghost tunnel requires two liquid crystal displays (LCDs), which are controlled by the same Arduino, to illuminate a 45-deg transparency sheet in both directions, allowing two different holograms to be viewed from each side of the tunnel. We have described a practical procedure for building the apparatus and validate its performance. Due to the simplicity of the apparatus, the Pepper Ghost tunnel allows undergraduate students to increase their knowledge in geometrical Optics and its integration with electrical circuits
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- Award ID(s):
- 2042563
- PAR ID:
- 10394114
- Date Published:
- Journal Name:
- Quaesitum
- Volume:
- 9
- ISSN:
- 2375-5423
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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