Design of compact augmented reality near-eye display using freeform holographic optical element

With the development of display technology, augmented reality (AR) devices have a wide range of application scenarios in many fields. The optical performance, volume and cost of the device are the main factors restricting the development of AR technology. As a traditional structure for optical combiner, birdbath faces challenges in achieving both a large field of view (FoV) and a lightweight, compact design. In this study, we introduce a novel off-axis configuration by replacing the polarized beam splitter (PBS) with a freeform holographic optical element (HOE). The system achieves a 46° FoV with a total thickness of 8.42mm, representing a 17.5% reduction in size compared to conventional PBS-based structures. Due to the wavefront manipulation by uniquely designed HOE, this approach significantly reduces system volume while maintaining high imaging performance. The proposed system holds potential for future AR applications where compactness, lightweight structures, and image quality are important factors.