Multi-focal plane near-eye display integrating polarizing beam splitters and liquid crystal variable retarder

With the rapid development of near-eye display (NED) technology, it has become a key device connecting the virtual world, widely used in various industries. However, most commercial NED systems have a limitation: they provide only a fixed virtual image distance, which restricts their performance in 3D visual effects and can lead to visual issues such as vergence-accommodation conflict. To address this issue, an augmented reality NED system was designed by integrating a liquid crystal variable retarder and polarizing beam splitter prisms in combination with freeform prisms. Four focal planes with a diopter range of 0.2D to 5D were achieved, covering the human eye's observation range from far to near. This paper details the optical design principles of this multi-focal NED system. A prototype was fabricated to validate the system's exceptional performance and broad application potential. The final system offers high image quality with a diagonal field of view of 40°, an exit pupil diameter of 8 mm, and an eye relief of 18 mm, which is based on a 0.23-inch micro-display.