A new study investigates the possibilities of a unique pancake optics system for next-generation VR and MR displays. Augmented reality (AR), virtual reality (VR), and mixed reality (MR) have broadened our perceptual frontiers, allowing for more complex human-digital interactions than typical flat-panel displays. This has resulted in applications for smart education, healthcare, navigation, gaming, entertainment, and smart manufacturing.
AR, VR, and MR displays must be tiny, attractive, lightweight, and power-efficient to become wearable for extended periods. Polarization-based folded optics, often pancake optics, have emerged as a breakthrough for compact and lightweight virtual reality headsets such as the Apple Vision Pro and Meta Quest 3. However, the applied half mirror results in significant optical loss, limiting maximum efficiency to 25%.
The researchers propose a game-changing pancake optics system that decreases the size of VR and MR displays while being highly efficient. This solution tackles issues such as low optical efficiency, high heat effect, and short battery life due to the half mirror. The nonreciprocal polarization rotator folds optical lines with a net rotation of 2θ.
Preliminary trials with a laser source and a micro-OLED panel demonstrated the proposed system’s optical efficiency and folding capacity. The optical efficiency increased to 93.2% after employing high-performance reflective polarizers with AR coating, which was close to theoretical expectations. The study also investigates four forms of ghost images and suggests new strategies for improving the image contrast ratio.
This unique pancake optics system has the potential to change next-generation VR and MR displays because of its lightweight, compact form factor and low power usage.
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