Large Étendue 3D Holographic Display with Content-adpative Dynamic Fourier Modulation

Brian Chao1, Manu Gopakumar1, Suyeon Choi1, Jonghyun Kim2, Liang Shi3, Gordon Wetzstein1,
1Stanford University 2NVIDIA 3MIT
SIGGRAPH Asia 2024
Paper arXiv Video Code (Coming Soon) Supplemental Material

Conventional single-source holoraphy only supports a small étendue, hence the observed image quickly degrades and fades to black when user's pupil moves away from the eyebox (b, c, d). Using multi-source illumination (a), our holographic display creates a significantly expanded coverage of addressable spatial frequencies (e), which, combined with our content-adaptive Fourier modulation strategy, achieves a large étendue with better image quality across an expanded eyebox (f, g).

Abstract

Emerging holographic display technology offers unique capabilities for next-generation virtual reality systems. Current holographic near-eye displays, however, only support a small étendue, which results in a direct tradeoff between achievable field of view and eyebox size. Étendue expansion has recently been explored, but existing approaches are either fundamentally limited in the image quality that can be achieved or they require extremely high-speed spatial light modulators.

We describe a new étendue expansion approach that combines multiple coherent sources with content-adaptive amplitude modulation of the hologram spectrum in the Fourier plane. To generate time-multiplexed phase and amplitude patterns for our spatial light modulators, we devise a pupil-aware gradient-descent-based computer-generated holography algorithm that is supervised by a large-baseline target light field. Compared with relevant baseline approaches, our method demonstrates significant improvements in image quality and étendue in simulation and with an experimental holographic display prototype.

Video

System Design

Previous étendue expansion techniques suffer from the following drawbacks:

  • Mask-based étendue expansion techniques reconstruct low-contrast and speckly images.
  • By using multiple sources, the eyebox is expanded but the light field reconstruction quality is poor due to copies created by multiple sources and HDOs.
  • Steered illumination configurations achieve decent image quality, however such approaches can only be implemented using high-speed SLMs due to the large number of required time-multiplexed frames.



By combining multiple coherent sources with content-adaptive amplitude modulation of the hologram spectrum in the Fourier plane, our system achieves the best image quality across the expanded eyebox while using less time-multiplexed frames.

Experimental Results

Hardware Prototype

We implement the proposed 3D holographic display design and evaluate our algorithms on the system. A custom-printed 3D mount is used to house the multisource laser array.


Captured Light Fields and Focal Stacks

We capture light fields and focal stacks displayed by our system using an adjustable iris and a focus-tunable lens. Parallax and in-focus/defocus are clearly visible in the captured results.

Related Projects

You might be interested in the following related projects from our lab, where we develop AI algorithms to produce 2D, 3D, and 4D holograms:

and holographic near-eye display designs for compact AR/VR glasses:

Acknowledgement

Brian Chao is supported by the Stanford Graduate Fellowship and the NSF GRFP. Manu Gopakumar is supported by the Stanford Gradudate Fellowship. Suyeon Choi is supported by the Meta Research PhD Fellowship.

BibTeX

@article{chao2024holoDFM,
  author    = {Brian Chao and Manu Gopakumar and Suyeon Choi and Jonghyun Kim and Liang Shi and Gordon Wetzstein},
  title     = {Large Étendue 3D Holographic Display with Content-adpative Dynamic Fourier Modulation},
  conference   = {ACM SIGGRAPH Asia},
  year      = {2024},
}