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

Abstract

Computer-generated holography suffers from high diffraction orders (HDOs) created from 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 HDOs and use it to optimize phase patterns, which allows HDOs to contribute to forming the image instead of creating artifacts. The proposed method significantly outperforms previous algorithms in an unfiltered holographic display prototype.

End-to-end learning of 3D phase-only holograms for holographic display

“…The current system also requires a Fourier filter to shield higher-order diffractions for producing a clean image. Changing the image formation model to model higher-order diffractions explicitly can potentially remove the need for optical filtering 46 and increase the method compatibility to enable more flexible display designs. Meanwhile, the current ground truth focal stack is rendered under the assumption of a coherent imaging model, the real-world depth of field yet follows the incoherent imaging model.…”

Deep-Learning Computational Holography: A Review

“…The following research is an extension of the camera-in-theloop holography: high-quality holographic display using partially coherent light (LED light source) (Peng et al, 2021), holographic display using Michelson setup to eliminate undiffracted light of SLM (Choi et al, 2021), optimizing binary phase holograms (Kadis et al, 2021), holographic display that suppresses highorder diffracted light using only computational processing without any physical filters (Gopakumar et al, 2021), and further improvement of image quality by using a Gaussian filter to remove noise that is difficult to optimize (Chen et al, 2022).…”

37‐1: Invited Paper: Advances in Neural Holographic Displays for Virtual and Augmented Reality

“…This direct optimization of the captured output enables significantly better image quality than traditional CGH algorithms. Additionally, by changing the simulated propagation models used to approximate the gradients, modified versions of this CITL optimization technique have also been demonstrated to produce state-of-the-art image quality for higher contrast holographic displays with two SLMs [5] and more compact holographic displays without optical filtering [10].…”