Breaking the optical efficiency limit of virtual reality with a nonreciprocal polarization rotator
用非互易偏振旋转器突破虚拟现实的光学效率极限
非相互偏光回転器を用いた仮想現実の光学効率限界の突破
비호환 편광 회전기로 가상 현실의 광학 효율 한계를 돌파하다
Romper el límite de eficiencia óptica de la realidad virtual con un rotor de polarización no recíproco
Repoussez les limites de l'efficacité optique de la réalité virtuelle avec un rotateur polarisant non réciproque
Преодоление предела оптической эффективности виртуальной реальности с помощью невзаимных поляризационных вращателей
¹ College of Optics and Photonics, University of Central Florida, Orlando FL 32816, USA
² Department of Intelligent Interaction Technologies, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
³ Research Fellow of Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo 102-0083, Japan
A catadioptric lens structure, also known as pancake lens, has been widely used in virtual reality (VR) displays to reduce the formfactor. However, the utilization of a half mirror (HM) to fold the optical path thrice leads to a significant optical loss. The theoretical maximum optical efficiency is merely 25%.
To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics, in this paper, we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization rotator. In our feasibility demonstration experiment, we used a commercial Faraday rotator (FR) and reflective polarizers to replace the lossy HM. The theoretically predicted 100% efficiency can be achieved approximately by using two high-extinction-ratio reflective polarizers.
In addition, we evaluated the ghost images using a micro-OLED panel in our imaging system. Indeed, the ghost images can be suppressed to undetectable level if the optics are with antireflection coating. Our novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight, compact formfactor, and low power consumption.
