awesome-holography
A curated list of resources on holographic displays.
Disclaimer
This list is compiled during my paper survey about holographic displays, and is not meant to be exhuastive. The list is organized for me to easily navigate different topics in holography. I would like to thank the authors of the following papers for providing great initial references:
Table of Contents
Background, Theory, and Survey
Background and Theory
Survey Papers
Computer Generated Holography (CGH) Algorithms
This section mainly focuses on the algorithmic aspect of holographic display systems.
Traditional Heuristic Methods
Point-based Methods
Polygon/Mesh-based Methods
Layer-based Methods
Holographic Stereograms
Iterative Methods
A family of iterative methods is based on the Gerchberg-Saxton (GS) Algorithm where the phase and amplitute patterns at two planes are updated iteratively as the wave propagates back and forth between the two planes:
Other optimization based methods leverage gradient descent or non-convex optimization techniques to optimize the phase pattern of the SLM:
Perceptual-driven loss designs
Others
Unfortunately, iterative methods are inherently slow and thus not suitble for real-time CGH. See this section for speeding up hologram synthesis using neural networks.
Learned Propagation Model Methods
There are often mismatches between a ideal wave propagation model (e.g. ASM) with the actual physical display setup. A major focus in deep learning for CGH is using camera-in-the-loop (CITL) training to learn an accurate free space wave propagation and optical hardware model for holographic displays:
- Neural Holography with Camera-in-the-loop Training (Peng et al. 2020 | SIGGRAPH, ACM) is the first to use camera-in-the-loop training (CITL) to optimize a parameterized wave propagation model, where optical aberrations, SLM non-linearities, and etc are learned from data. A CNN is also proposed to synthesize 2D and 3D holograms in real-time.
- Neural 3D Holography: Learning Accurate Wave Propagation Models for 3D Holographic Virtual and Augmented Reality Displays (Choi et al. 2021 | SIGGRAPH Asia, ACM) uses two CNNs to directly model optical aberrations, SLM non-linearities, and etc, at the input plane and multiple target planes. The usage of two CNNs introduces more degrees of freedom than that of the parameterized propagation model proposed in Peng et al. 2020, such that higher quality 3D holograms can be achieved.
- Time-multiplexed Neural Holography: A Flexible Framework for Holographic Near-eye Displays with Fast Heavily-quantized Spatial Light Modulators (Choi et al. 2022 | SIGGRAPH, ACM) leveraged time-multiplexed quantized SLM patterns to synthesize high quality defocus blur.
- Learned Hardware-in-the-loop Phase Retrieval for Holographic Near-Eye Displays (Chakravarthula et al. 2020 | SIGGGRAPH Asia, ACM) uses CITL to learn an aberration approximator that models the residual between holograms generated from ideal wave propagation (i.e. ASM) and real-world wave propagation models. An adversarial loss is used in addition to reconstruction loss to optimize the synthesized holograms.
- Learned holographic light transport (Kavaklı et al. 2021 | Applied Optics, Optica) learns the wave propagation convolution kernel directly from images captured by a physical holographic display, instead of using the ASM method to propagate fields.
Learned Hologram Synthesis Methods
These works often assume a naive wave propagation model (i.e. the angular spectrum method (ASM)), and directly regresses complex holograms using novel CNN architectures:
Topics in Holographic Display Systems
Speckle Noise Reduction
Speckle noise is a result of interference among coherent waves, which is often present in holographic images since holographic displays use coherent laser sources. Methods for reducing speckle noise can roughly be catergorized into the following:
Time-averaging
- High‐contrast, speckle‐free, true 3D holography via binary CGH optimization (Lee et al. 2022 | Scientific Reports, Nature) optimized random phase, amplitude only SLMs using gradient descent and time-averaged them to reduce speckle noise.
- DCGH: Dynamic Computer Generated Holography for Speckle-Free, High Fidelity 3D Displays (Curtis et al. 2021 | IEEE, VR) simultaneously optimizes multiple binary, amplitude only SLMs in a modified Gerchberg-Saxton (GS) algorithm and time-averages them to reduce speckle noise.
Partially-coherent Light Sources
- Speckle-free holography with partially coherent light sources and camera-in-the-loop calibration (Peng et al. 2021 | Science Advaces, Science) uses partially coherent light sources (i.e. LED) and camera-in-the-loop optimization to reduce speckle noise.
- Light source optimization for partially coherent holographic displays with consideration of speckle contrast, resolution, and depth of field (Lee et al. 2020 | Scientific Reports, Nature)
- Holographic head-mounted display with RGB light emitting diode light source (Moon et al. 2014 | Optics Express, Optica)
Others
- Optimizing image quality for holographic near-eye displays with Michelson Holography (Choi et al. 2021 | Optica, Optica) uses 2 SLMs to correct for the unwanted interference caused by undiffracted light in single-SLM settings. A CITL procedure is also deployed to simultaneously optimize 2 SLM patterns.
Etendue Expansion
The product of the field of view (FoV) and the eyebox size, the etendue, is limited by the number of pixels on the SLM. Hence, there is an inherent tradeoff between these two properties.
Holographic Optical Elements (HOEs)
Small Form-factor Displays
Bulky headsets hamper the development of AR/VR. Reducing the size of holographic displays are important:
Compression
CGH compression is also important for deploying holography technology on edge devices:
Zero or Higher Diffraction Orders Optimization
- Unfiltered holography: optimizing high diffraction orders without optical filtering for compact holographic displays g(Gopakumar et al. 2021 | Optics Letters, Optica) incorporated higher diffraction orders into the CGH optimization procedure to remove the 4f filtering system often used in holographic displays, thus reducing the display form factor.
- Elimination of a zero-order beam induced by a pixelated spatial light modulator for holographic projection (Zhang et al. 2009 | Applied Optics, Optica)
- Holographic projection of arbitrary light patterns with a suppressed zero-order beam
- Effect of spurious diffraction orders in arbitrary multifoci patterns produced via phase-only holograms
- Off-axis camera-in-the-loop optimization with noise reduction strategy for high-quality hologram generation (Chen et al. 2022 | Optics Letters, Optica)
Labs and Researchers
Talks, Lectures, and Tutorials
Contributing
If you want to contribute to this list, please
- Created a new issue
- Explain in the issue why the paper / book / talk is relevant, and under which category should the resource be placed.
Thank you!