Accommodative holography: improving accommodation response for perceptually realistic holographic displays

Author(s):

Kim, Dongyeon; Nam, Seung-Woo; Lee, Byounghyo; Seo, Jong-Mo & Lee, Byoungho

Abstract:

“Holographic displays have gained unprecedented attention as next-generation virtual and augmented reality applications with recent achievements in the realization of a high-contrast image through computer-generated holograms (CGHs). However, these holograms show a high energy concentration in a limited angular spectrum, whereas the holograms with uniformly distributed angular spectrum suffer from a severe speckle noise in the reconstructed images. In this study, we claim that these two physical phenomena attributed to the existing CGHs significantly limit the support of accommodation cues, which is known as one of the biggest advantages of holographic displays. To support the statement, we analyze and evaluate various CGH algorithms with contrast gradients – a change of contrast over the change of the focal diopter of the eye – simulated based on the optical configuration of the display system and human visual perception models. We first introduce two approaches to improve monocular accommodation response in holographic viewing experience; optical and computational approaches to provide holographic images with sufficient contrast gradients. We design and conduct user experiments with our prototype of holographic near-eye displays, validating the deficient support of accommodation cues in the existing CGH algorithms and demonstrating the feasibility of the proposed solutions with significant improvements on accommodative gains.”

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Publication: ACM Transactions on Graphics
Issue/Year: ACM Transactions on Graphics, Volume 41; Number 4; Pages 1–15; 2022
DOI: 10.1145/3528223.3530147

Multi-beam heterodyne laser Doppler vibrometer based on a line-scan CMOS digital camera

Author(s):

Aranchuk, Vyacheslav; Kasu, Ramachandran; Li, Junrui; Aranchuk, Ina & Hickey, Craig

Abstract:

“Multi-beam laser Doppler vibrometers (MB-LDVs) have an advantage over scanning single-beam laser Doppler vibrometers (LDVs) due to the reduction in measurement time and their ability to measure non-stationary and transient events. However, the number of simultaneously interrogated points in current MB-LDVs is limited due to the complexity of the electronic hardware, which increases with the number of measurement channels. Recent developments of high-speed line-scan CMOS cameras suggest that their use in MB-LDVs can reduce the hardware complexity and increase the number of measurement channels. We developed a MB-LDV based on a digital line-scan CMOS camera that simultaneously measures vibrations on a linear array of 99 points. The experimental setup and performance of the developed MB-LDV are discussed in this paper.”

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Publication: Appl. Opt.
Issue/Year: Appl. Opt., Volume 61; Number 20; Pages 5876–5883; 2022
DOI: 10.1364/AO.461368

Generalized Talbot Self-Healing of Periodic Images

Author(s):

Rowe, Connor M. L.; Cortes, Luis Romero; de Chatellus, Hugues Guillet; Seghilani, Mohamed & Azana, Jose

Abstract:

“Spatially periodic images are useful in a broad range of scientific fields, but are often corrupted by spatial jitter, noise, or missing repetitions. We review recent work on the use of diffraction-induced Talbot self-imaging to recover corrupted periodic images through a passive amplification process.”

Link to Publications Page

Publication: IEEE Photonics Society Summer Topicals Meeting Series (SUM)
Issue/Year: IEEE Photonics Society Summer Topicals Meeting Series (SUM), Cabo San Lucas, Mexico, 2022
DOI: 10.1109/sum53465.2022.9858325