Multi-depth hologram generation using stochastic gradient descent algorithm with complex loss function

Optics Express, Год журнала: 2021, Номер 29(10), С. 15089 - 15089

Опубликована: Апрель 20, 2021

The stochastic gradient descent (SGD) method is useful in the phase-only hologram optimization process and can achieve a high-quality holographic display. However, for current SGD solution multi-depth generation, time increases dramatically as number of depth layers object increases, leading to nearly impractical generation complicated three-dimensional object. In this paper, proposed uses complex loss function instead an amplitude-only process. This substitution ensures that total be obtained through only one calculation, reduced hugely. Moreover, since both amplitude phase parts are optimized, obtain relatively accurate distribution. defocus blur effect therefore matched with result from reconstruction. Numerical simulations optical experiments have validated effectiveness method.

Язык: Английский

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Deep-Learning Computational Holography: A Review

Frontiers in Photonics, Год журнала: 2022, Номер 3

Опубликована: Март 28, 2022

Deep learning has been developing rapidly, and many holographic applications have investigated using deep learning. They shown that can outperform previous physically-based calculations lightwave simulation signal processing. This review focuses on computational holography, including computer-generated holograms, displays, digital We also discuss our personal views the promise, limitations future potential of in holography.

Язык: Английский

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Time-multiplexed Neural Holography: A Flexible Framework for Holographic Near-eye Displays with Fast Heavily-quantized Spatial Light Modulators

Опубликована: Июль 20, 2022

Holographic near-eye displays offer unprecedented capabilities for virtual and augmented reality systems, including perceptually important focus cues. Although artificial intelligence–driven algorithms computer-generated holography (CGH) have recently made much progress in improving the image quality synthesis efficiency of holograms, these are not directly applicable to emerging phase-only spatial light modulators (SLM) that extremely fast but phase control with very limited precision. The speed SLMs offers time multiplexing capabilities, essentially enabling partially-coherent holographic display modes. Here we report advances camera-calibrated wave propagation models types develop a CGH framework robustly optimizes heavily quantized patterns SLMs. Our is flexible supporting runtime supervision different content, 2D 2.5D RGBD images, 3D focal stacks, 4D fields. Using our framework, demonstrate state-of-the-art results all scenarios simulation experiment.

Язык: Английский

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Non-convex optimization for inverse problem solving in computer-generated holography

Light Science & Applications, Год журнала: 2024, Номер 13(1)

Опубликована: Июль 9, 2024

Abstract Computer-generated holography is a promising technique that modulates user-defined wavefronts with digital holograms. Computing appropriate holograms faithful reconstructions not only problem closely related to the fundamental basis of but also long-standing challenge for researchers in general fields optics. Finding exact solution desired hologram reconstruct an accurate target object constitutes ill-posed inverse problem. The practice single-diffraction computation synthesizing can provide approximate answer, which subject limitations numerical implementation. Various non-convex optimization algorithms are thus designed seek optimal by introducing different constraints, frameworks, and initializations. Herein, we overview applied computer-generated holography, incorporating principles synthesis based on alternative projections gradient descent methods. This aimed underlying optimized generation, as well insights into cutting-edge developments this rapidly evolving field potential applications virtual reality, augmented head-up display, data encryption, laser fabrication, metasurface design.

Язык: Английский

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Ergonomic‐Centric Holography: Optimizing Realism, Immersion, and Comfort for Holographic Display

Laser & Photonics Review, Год журнала: 2024, Номер 18(4)

Опубликована: Фев. 25, 2024

Abstract Ergonomic‐centric holography is introduced, an algorithmic framework that simultaneously optimizes for realistic incoherent defocus, unrestricted pupil movements in the eye box, and high‐order diffractions filtering‐free holography. The proposed method outperforms prior algorithms on holographic display prototypes operating unfiltered pupil‐mimicking modes, offering potential to enhance next‐generation virtual augmented reality experiences.

Язык: Английский

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Ultrahigh-fidelity full-color holographic display via color-aware optimization

PhotoniX, Год журнала: 2024, Номер 5(1)

Опубликована: Июнь 1, 2024

Abstract Holographic display offers the capability to generate high-quality images with a wide color gamut since it is laser-driven. However, many existing holographic techniques fail fully exploit this potential, primarily due system’s imperfections. Such flaws often result in inaccurate representation, and there lack of an efficient way address accuracy issue. In study, we develop color-aware hologram optimization approach for color-accurate displays. Our integrates both laser camera into loop, enabling dynamic laser’s output acquisition physically captured feedback. Moreover, improve efficiency process video We introduce cascade strategy, which leverages redundant neighbor information accelerate iterative process. evaluate our method through simulation optical experiments, demonstrating superiority terms image quality, accuracy, speed compared previous algorithms. verifies promising realize high-fidelity display, provides new direction toward practical display.

Язык: Английский

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Holographic Glasses for Virtual Reality

Опубликована: Июль 20, 2022

We present Holographic Glasses, a holographic near-eye display system with an eyeglasses-like form factor for virtual reality. Glasses are composed of pupil-replicating waveguide, spatial light modulator, and geometric phase lens to create images in lightweight thin factor. The proposed design can deliver full-color 3D using optical stack 2.5 mm thickness. A novel pupil-high-order gradient descent algorithm is presented the correct calculation user's varying pupil size. implement benchtop wearable prototypes testing. Our binocular prototype supports focus cues provides diagonal field view 22.8° 2.3 static eye box additional capabilities dynamic beam steering, while weighing only 60 g excluding driving board.

Язык: Английский

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Real-time High-Quality Computer-Generated Hologram Using Complex-Valued Convolutional Neural Network

IEEE Transactions on Visualization and Computer Graphics, Год журнала: 2023, Номер 30(7), С. 3709 - 3718

Опубликована: Янв. 25, 2023

Holographic displays are ideal display technologies for virtual and augmented reality because all visual cues provided. However, real-time high-quality holographic difficult to achieve the generation of computer-generated hologram (CGH) is inefficient in existing algorithms. Here, complex-valued convolutional neural network (CCNN) proposed phase-only CGH generation. The CCNN-CGH architecture effective with a simple structure based on character design complex amplitude. A prototype set up optical reconstruction. Experiments verify that state-of-the-art performance achieved terms quality speed end-to-end holography methods using wave propagation model. three times faster than HoloNet one-sixth Holo-encoder, Peak Signal Noise Ratio (PSNR) increased by 3 dB 9 dB, respectively. Real-time CGHs generated 1920 × 1072 3840 2160 resolutions dynamic displays.

Язык: Английский

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Unfiltered holography: optimizing high diffraction orders without optical filtering for compact holographic displays

Optics Letters, Год журнала: 2021, Номер 46(23), С. 5822 - 5822

Опубликована: Ноя. 1, 2021

Computer-generated holography suffers from high diffraction orders (HDOs) created pixelated spatial light modulators, which must be optically filtered using bulky optics. Here, we develop an algorithmic framework for optimizing HDOs without optical filtering to enable compact holographic displays. We devise a wave propagation model of and use it optimize phase patterns, allows contribute forming the image instead creating artifacts. The proposed method significantly outperforms previous algorithms in unfiltered display prototype.

Язык: Английский

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Gaze-Contingent Retinal Speckle Suppression for Perceptually-Matched Foveated Holographic Displays

IEEE Transactions on Visualization and Computer Graphics, Год журнала: 2021, Номер 27(11), С. 4194 - 4203

Опубликована: Авг. 27, 2021

Computer-generated holographic (CGH) displays show great potential and are emerging as the next-generation for augmented virtual reality, automotive heads-up displays. One of critical problems harming wide adoption such is presence speckle noise inherent to holography, that compromises its quality by introducing perceptible artifacts. Although suppression has been an active research area, previous works have not considered perceptual characteristics Human Visual System (HVS), which receives final displayed imagery. However, it well studied sensitivity HVS uniform across visual field, led gaze-contingent rendering schemes maximizing in various computer-generated Inspired this, we present first method reduces "perceived noise" integrating foveal peripheral vision HVS, along with retinal point spread function, into phase hologram computation. Specifically, introduce anatomical statistical receptor distribution our computational optimization, places a higher priority on reducing perceived while being adaptable any individual's optical aberration retina. Our demonstrates superior emulated display. evaluations objective measurements subjective studies demonstrate significant reduction human noise.

Язык: Английский

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