{"title":"利用偏振体光栅打破基于波导的 AR 显示屏的内耦合效率限制。","authors":"Yuqiang Ding, Yuchen Gu, Qian Yang, Zhiyong Yang, Yuge Huang, Yishi Weng, Yuning Zhang, Shin-Tson Wu","doi":"10.1038/s41377-024-01537-8","DOIUrl":null,"url":null,"abstract":"<p><p>Augmented reality (AR) displays, heralded as the next-generation platform for spatial computing, metaverse, and digital twins, empower users to perceive digital images overlaid with real-world environment, fostering a deeper level of human-digital interactions. With the rapid evolution of couplers, waveguide-based AR displays have streamlined the entire system, boasting a slim form factor and high optical performance. However, challenges persist in the waveguide combiner, including low optical efficiency and poor image uniformity, significantly hindering the long-term usage and user experience. In this paper, we first analyze the root causes of the low optical efficiency and poor uniformity in waveguide-based AR displays. We then discover and elucidate an anomalous polarization conversion phenomenon inherent to polarization volume gratings (PVGs) when the incident light direction does not satisfy the Bragg condition. This new property is effectively leveraged to circumvent the tradeoff between in-coupling efficiency and eyebox uniformity. Through feasibility demonstration experiments, we measure the light leakage in multiple PVGs with varying thicknesses using a laser source and a liquid-crystal-on-silicon light engine. The experiment corroborates the polarization conversion phenomenon, and the results align with simulation well. To explore the potential of such a polarization conversion phenomenon further, we design and simulate a waveguide display with a 50° field of view. Through achieving first-order polarization conversion in a PVG, the in-coupling efficiency and uniformity are improved by 2 times and 2.3 times, respectively, compared to conventional couplers. This groundbreaking discovery holds immense potential for revolutionizing next-generation waveguide-based AR displays, promising a higher efficiency and superior image uniformity.</p>","PeriodicalId":18093,"journal":{"name":"Light, science & applications","volume":null,"pages":null},"PeriodicalIF":19.4000,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11317523/pdf/","citationCount":"0","resultStr":"{\"title\":\"Breaking the in-coupling efficiency limit in waveguide-based AR displays with polarization volume gratings.\",\"authors\":\"Yuqiang Ding, Yuchen Gu, Qian Yang, Zhiyong Yang, Yuge Huang, Yishi Weng, Yuning Zhang, Shin-Tson Wu\",\"doi\":\"10.1038/s41377-024-01537-8\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Augmented reality (AR) displays, heralded as the next-generation platform for spatial computing, metaverse, and digital twins, empower users to perceive digital images overlaid with real-world environment, fostering a deeper level of human-digital interactions. With the rapid evolution of couplers, waveguide-based AR displays have streamlined the entire system, boasting a slim form factor and high optical performance. However, challenges persist in the waveguide combiner, including low optical efficiency and poor image uniformity, significantly hindering the long-term usage and user experience. In this paper, we first analyze the root causes of the low optical efficiency and poor uniformity in waveguide-based AR displays. We then discover and elucidate an anomalous polarization conversion phenomenon inherent to polarization volume gratings (PVGs) when the incident light direction does not satisfy the Bragg condition. This new property is effectively leveraged to circumvent the tradeoff between in-coupling efficiency and eyebox uniformity. Through feasibility demonstration experiments, we measure the light leakage in multiple PVGs with varying thicknesses using a laser source and a liquid-crystal-on-silicon light engine. The experiment corroborates the polarization conversion phenomenon, and the results align with simulation well. To explore the potential of such a polarization conversion phenomenon further, we design and simulate a waveguide display with a 50° field of view. Through achieving first-order polarization conversion in a PVG, the in-coupling efficiency and uniformity are improved by 2 times and 2.3 times, respectively, compared to conventional couplers. This groundbreaking discovery holds immense potential for revolutionizing next-generation waveguide-based AR displays, promising a higher efficiency and superior image uniformity.</p>\",\"PeriodicalId\":18093,\"journal\":{\"name\":\"Light, science & applications\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":19.4000,\"publicationDate\":\"2024-08-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11317523/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Light, science & applications\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1038/s41377-024-01537-8\",\"RegionNum\":1,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"Physics and Astronomy\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Light, science & applications","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1038/s41377-024-01537-8","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
摘要
增强现实(AR)显示器被誉为空间计算、元宇宙和数字孪生的下一代平台,使用户能够感知与现实世界环境相叠加的数字图像,从而促进更深层次的人机交互。随着耦合器的快速发展,基于波导的 AR 显示器简化了整个系统,具有纤薄的外形和较高的光学性能。然而,波导合路器仍面临着光学效率低、图像均匀性差等挑战,严重影响了长期使用和用户体验。在本文中,我们首先分析了基于波导的 AR 显示屏光学效率低和均匀性差的根本原因。然后,我们发现并阐明了当入射光方向不满足布拉格条件时,偏振体积光栅(PVG)固有的异常偏振转换现象。利用这一新特性,可以有效规避内耦合效率和眼罩均匀性之间的权衡。通过可行性论证实验,我们利用激光源和硅基液晶光引擎测量了厚度不同的多个 PVG 的漏光情况。实验证实了偏振转换现象,结果与模拟结果吻合。为了进一步探索这种偏振转换现象的潜力,我们设计并模拟了一个视场角为 50° 的波导显示器。通过在 PVG 中实现一阶偏振转换,与传统耦合器相比,内耦合效率和均匀性分别提高了 2 倍和 2.3 倍。这一突破性发现为下一代基于波导的 AR 显示屏带来了巨大的变革潜力,有望实现更高的效率和卓越的图像均匀性。
Breaking the in-coupling efficiency limit in waveguide-based AR displays with polarization volume gratings.
Augmented reality (AR) displays, heralded as the next-generation platform for spatial computing, metaverse, and digital twins, empower users to perceive digital images overlaid with real-world environment, fostering a deeper level of human-digital interactions. With the rapid evolution of couplers, waveguide-based AR displays have streamlined the entire system, boasting a slim form factor and high optical performance. However, challenges persist in the waveguide combiner, including low optical efficiency and poor image uniformity, significantly hindering the long-term usage and user experience. In this paper, we first analyze the root causes of the low optical efficiency and poor uniformity in waveguide-based AR displays. We then discover and elucidate an anomalous polarization conversion phenomenon inherent to polarization volume gratings (PVGs) when the incident light direction does not satisfy the Bragg condition. This new property is effectively leveraged to circumvent the tradeoff between in-coupling efficiency and eyebox uniformity. Through feasibility demonstration experiments, we measure the light leakage in multiple PVGs with varying thicknesses using a laser source and a liquid-crystal-on-silicon light engine. The experiment corroborates the polarization conversion phenomenon, and the results align with simulation well. To explore the potential of such a polarization conversion phenomenon further, we design and simulate a waveguide display with a 50° field of view. Through achieving first-order polarization conversion in a PVG, the in-coupling efficiency and uniformity are improved by 2 times and 2.3 times, respectively, compared to conventional couplers. This groundbreaking discovery holds immense potential for revolutionizing next-generation waveguide-based AR displays, promising a higher efficiency and superior image uniformity.
期刊介绍:
Light: Science & Applications is an open-access, fully peer-reviewed publication.It publishes high-quality optics and photonics research globally, covering fundamental research and important issues in engineering and applied sciences related to optics and photonics.