Holographic near-eye display with continuously expanded eyebox using two-dimensional replication and angular spectrum wrapping

Author(s):

Myeong-Ho Choi, Yeon-Gyeong Ju and Jae-Hyeung Park

Abstract:

“Holographic near-eye displays present true three-dimensional images with full
monocular depth cues. In this paper, we propose a technique to expand the eyebox of the
holographic near-eye displays. The base eyebox of the holographic near-eye displays is determined
by the space bandwidth product of a spatial light modulator. The proposed technique replicates
and stitches the base eyebox by the combined use of a holographic optical element and high order
diffractions of the spatial light modulator, achieving horizontally and vertically expanded eyebox.
An angular spectrum wrapping technique is also applied to alleviate image distortions observed
at the boundaries between the replicated base eyeboxes.”

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Publication: Optics Express
Issue/Year: Vol. 28, Issue 1, pp. 533-547
DOI: 10.1364/OE.381277

Wirtinger holography for near-eye displays

Author(s):

Chakravarthula, Praneeth; Peng, Yifan; Kollin, Joel; Fuchs, Henry & Heide, Felix

Abstract:

“Near-eye displays using holographic projection are emerging as an exciting display approach for virtual and augmented reality at high-resolution without complex optical setups — shifting optical complexity to computation. While precise phase modulation hardware is becoming available, phase retrieval algorithms are still in their infancy, and holographic display approaches resort to heuristic encoding methods or iterative methods relying on various relaxations.
In this work, we depart from such existing approximations and solve the phase retrieval problem for a hologram of a scene at a single depth at a given time by revisiting complex Wirtinger derivatives, also extending our framework to render 3D volumetric scenes. Using Wirtinger derivatives allows us to pose the phase retrieval problem as a quadratic problem which can be minimized with first-order optimization methods. The proposed Wirtinger Holography is flexible and facilitates the use of different loss functions, including learned perceptual losses parametrized by deep neural networks, as well as stochastic optimization methods. We validate this framework by demonstrating holographic reconstructions with an order of magnitude lower error, both in simulation and on an experimental hardware prototype.”

Link to Publications Page

Publication: ACM Transactions on Graphics (TOG)
Issue/Year: ACM Transactions on Graphics (TOG), Volume 38; Number 6; Pages 213; 2019
DOI: 10.1145/3355089.3356539

Holographic Three-Dimensional Virtual Reality and Augmented Reality Display Based on 4K-Spatial Light Modulators

Author(s):

Gao, Hongyue; Xu, Fan; Liu, Jicheng; Dai, Zehang; Zhou, Wen; Li, Suna; Yu, Yingjie & Zheng, Huadong

Abstract:

“In this paper, we propose a holographic three-dimensional (3D) head-mounted display based on 4K-spatial light modulators (SLMs). This work is to overcome the limitation of stereoscopic 3D virtual reality and augmented reality head-mounted display. We build and compare two systems using 2K and 4K SLMs with pixel pitches 8.1 μm and 3.74 μm, respectively. One is a monocular system for each eye, and the other is a binocular system using two tiled SLMs for two eyes. The viewing angle of the holographic head-mounted 3D display is enlarged from 3.8° to 16.4° by SLM tiling, which demonstrates potential applications of true 3D displays in virtual reality and augmented reality.”

Link to Publications Page

Publication: Applied Sciences
Issue/Year: Applied Sciences, Volume 9; Number 6; Pages 1182; 2019
DOI: 10.3390/app9061182

A full-color compact 3D see-through near-eye display system based on complex amplitude modulation

Author(s):

Zhang, Zhiqi; Liu, Juan; Gao, Qiankun; Duan, Xinhui & Shi, Xueliang

Abstract:

“For complex amplitude modulation (CAM)-based three-dimensional (3D) near-eye systems, it is a challenge to realize colorful 3D display by using spatial light modulator (SLM) and grating. Here, a full-color compact 3D see-through near-eye display (NED) system by CAM is proposed. Computer generated holograms (CGHs) for different wavelengths are calculated separately. Each CGH contains two position-shifted sub-holograms and the separated distance is carefully calibrated to eliminate chromatic aberration. Colorful 3D images are synthesized through time-multiplexing. Color managements are performed and chromatic aberration of the system is analyzed to provide better colorful effect. The system structure is integrated to be compact and a prototype is implemented. Pre-compensation is added on CGHs to offset the system’s assembling errors. Optical experiment results show that the proposed system can provide good 3D full-color see-through performance without vergence-accommodation conflict (VAC). Dynamic colorful display ability is also tested, which shows good potential for interactive NED in the future.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 27; Number 5; Pages 7023; 2019
DOI: 10.1364/oe.27.007023

Optical see-through holographic near-eye-display with eyebox steering and depth of field control

Author(s):
Jae-Hyeung Park and Seong-Bok Kim

Abstract:

“We propose an optical see-through holographic near-eye-display that can control the depth of field of individual virtual three-dimensional image and replicate the eyebox with dynamic steering. For optical see-through capability and eyebox duplication, a holographic optical element is used as an optical combiner where it functions as multiplexed tilted concave mirrors forming multiple copies of the eyebox. Fo1r depth of field control and eyebox steering, computer generated holograms of three-dimensional objects are synthesized with different ranges of angular spectrum. In optical experiment, it has been confirmed that the proposed system can present always-focused images with large depth of field and three-dimensional images at different distances with shallow depth of field at the same time without any time-multiplexing.”

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Publication: Optics Express
Issue/Year: Optics Express Volume 26, Issue 21
DOI: 10.1364/oe.26.027076

Compact design for optical-see-through holographic displays employing holographic optical elements

Author(s):

Pengcheng Zhou and Yan Li and Shuxin Liu and Yikai Su

Abstract:

“Holographic AR display is a promising technology for head-mounted display devices. However, it usually has a complicated optical system and a large form factor, preventing it from widespread applications. In this work, we propose a flat-panel design to produce a compact holographic AR display, where traditional optical elements are replaced by two holographic optical elements (HOEs). Here, these two thin HOEs together perform the optical functions of a beam expander, an ocular lens, and an optical combiner. Without any bulky traditional optics, our design could achieve a compact form factor that is similar to a pair of glasses. We also implemented a proof-of-concept prototype to verify its feasibility. Being compact, lightweight and free from accommodation-convergence discrepancy, our design is promising for fatigue-free AR displays.”

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Publication: Optics Express
Issue/Year: Optics Express Volume 26, Issue 18
DOI: 10.1364/OE.26.022866

Holographic near-eye display system based on double-convergence light Gerchberg-Saxton algorithm

Author(s):

Peng Sun and Shengqian Chang and Siqi Liu and Xiao Tao and Chang Wang and Zhenrong Zheng

Abstract:

“In this paper, a method is proposed to implement noises reduced three-dimensional (3D) holographic near-eye display by phase-only computer-generated hologram (CGH). The CGH is calculated from a double-convergence light Gerchberg-Saxton (GS) algorithm, in which the phases of two virtual convergence lights are introduced into GS algorithm simultaneously. The first phase of convergence light is a replacement of random phase as the iterative initial value and the second phase of convergence light will modulate the phase distribution calculated by GS algorithm. Both simulations and experiments are carried out to verify the feasibility of the proposed method. The results indicate that this method can effectively reduce the noises in the reconstruction. Field of view (FOV) of the reconstructed image reaches 40 degrees and experimental light path in the 4-f system is shortened. As for 3D experiments, the results demonstrate that the proposed algorithm can present 3D images with 180cm zooming range and continuous depth cues. This method may provide a promising solution in future 3D augmented reality (AR) realization.”

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Publication: Optics Express
Issue/Year: Optics Express, Vol. 26, Issue 8, pp. 10140- 10151 (2018)
DOI: 10.1364/OE.26.010140

Near-eye light field holographic rendering with spherical waves for wide field of view interactive 3D computer graphics

Author(s):

Liang Shi and Fu-Chung Huang and Ward Lopes and Wojciech Matusik and David Luebke

Abstract:

“Holograms display a 3D image in high resolution and allow viewers to focus freely as if looking through a virtual window, yet computer generated holography (CGH) hasn’t delivered the same visual quality under plane wave illumination and due to heavy computational cost. Light field displays have been popular due to their capability to provide continuous focus cues. However, light field displays must trade off between spatial and angular resolution, and do not model diffraction.

We present a light field-based CGH rendering pipeline allowing for reproduction of high-definition 3D scenes with continuous depth and support of intra-pupil view-dependent occlusion. Our rendering accurately accounts for diffraction and supports various types of reference illuminations for hologram. We avoid under- and over-sampling and geometric clipping effects seen in previous work. We also demonstrate an implementation of light field rendering plus the Fresnel diffraction integral based CGH calculation which is orders of magnitude faster than the state of the art [Zhang et al. 2015], achieving interactive volumetric 3D graphics.

To verify our computational results, we build a see-through, near-eye, color CGH display prototype which enables co-modulation of both amplitude and phase. We show that our rendering accurately models the spherical illumination introduced by the eye piece and produces the desired 3D imagery at the designated depth. We also analyze aliasing, theoretical resolution limits, depth of field, and other design trade-offs for near-eye CGH.”

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Publication: {ACM} Transactions on Graphics
Issue/Year: ACM Transactions on Graphics, Vol. 36, No. 6, Article 236. (November 2017)
DOI: 10.1145/3130800.3130832

Holographic near-eye displays for virtual and augmented reality

Author(s):

Maimone, Andrew and Georgiou, Andreas and Kollin, Joel S

Abstract:
“We present novel designs for virtual and augmented reality near-eye displays based on phase-only holographic projection. Our approach is built on the principles of Fresnel holography and double phase amplitude encoding with additional hardware, phase correction factors, and spatial light modulator encodings to achieve full color, high contrast and low noise holograms with high resolution and true per-pixel focal control. We provide a GPU-accelerated implementation of all holographic computation that integrates with the standard graphics pipeline and enables real-time (≥90 Hz) calculation directly or through eye tracked approximations. A unified focus, aberration correction, and vision correction model, along with a user calibration process, accounts for any optical defects between the light source and retina. We use this optical correction ability not only to x minor aberrations but to enable truly compact, eyeglasses-like displays with wide elds of view (80◦) that would be inaccessible through conventional means. All functionality is evaluated across a series of hardware prototypes; we discuss remaining challenges to incorporate all features into a single device.”

Link to Publications Page

Publication: ACM Transactions on Graphics (TOG)
Issue/Year: ACM Transactions on Graphics, Vol. 36, No. 4, Article 85. (July 2017)
DOI: 10.1145/3072959.3073624
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