SUSTech has made breakthrough progress in the field of AR optical waveguide technology

Recently, the team of Professor Sun Xiaowei, chairman of the alliance and executive director of the Institute of Nanoscience and Applications of Southern University of Science and Technology, published a research paper titled "An achromatic metasurface waveguide for augmented reality displays" in the top international academic journal "Light: Science & Applications". This research proposes an innovative metasurface optical waveguide technology, which fundamentally solves the chromatic aberration problem in augmented reality displays for the first time and opens up a new direction for the development of AR display technology.

In the evolution of AR technology, display systems have always faced the dual challenges of “clearer” and “thinner”. From early mirror displays to today's optical waveguide displays, every iteration of technology is moving toward this goal. Diffractive optical waveguides have become the core technology of mainstream AR devices such as HoloLens and Meta Orion due to their ultra-thin characteristics. However, the problem of image distortion caused by dispersion effects has always been a technical problem in this field. bottleneck.

Figure 1. Schematic diagram of the metasurface optical waveguide AR display system

Through an innovative reverse design method, Sun Xiaowei's team proposed a brand-new solution: using a metasurface coupler and a single-layer high refractive index optical waveguide, they successfully overcome the chromatic aberration problem. Metasurface is an optical element composed of artificial nanostructures that can precisely control the phase, amplitude and polarization characteristics of light. By optimizing the geometric structure design of the metasurface coupler, the research team ensures that the RGB three-color light has consistent deflection angles and coupling efficiency when emitted, thereby effectively eliminating the chromatic aberration problem.

Figure 2. Comparison of traditional optical waveguides and metasurface optical waveguides. The traditional optical waveguide couples light into the optical waveguide through first-order diffraction, resulting in a wavelength-dependent deflection angle; the K vector diagram of the traditional optical waveguide has a smaller overlapping full-color field of view; the metasurface optical waveguide achieves chromatic aberration-free optical coupling through high-order diffraction; the K vector diagram of the metasurface optical waveguide has a larger full-color field of view.

This technological breakthrough not only solves the chromatic aberration bottleneck of traditional coupling devices, but also provides a new technical path for full-color optical waveguide displays. Metasurface waveguide technology has many significant advantages: the single-layer structure simplifies the manufacturing process, the high refractive index design expands the field of view, and the optimized coupling efficiency ensures full-color display effects. These characteristics enable it to show great application potential in the next generation of AR devices, marking that AR display technology is about to enter a new stage of development.

Figure 3. AR full-color display effect.

The first author of this research work is Tian Zhongtao, a doctoral candidate jointly trained by Southern University of Science and Technology and Pengcheng Laboratory, and Professor Sun Xiaowei is the only corresponding author. Southern University of Science and Technology is the first communication unit, and Pengcheng Laboratory is the second communication unit. The research was supported by the National Ministry of Science and Technology’s Key Research and Development Program and funding from units such as Guangdong Province and Shenzhen City.