With the development of virtual reality, the projection design of the head-mounted display (HMD) requires improvement as well. The surface relief grating (SRG) is one of the popular diffraction elements to achieve light guiding through the waveguide. Using the SRG as the coupler, incoming information light can be coupled into the waveguide by the 1-order diffraction. To increase possible design options for the HMD, SRG with complex geometry has been designed to fit more diffraction conditions. In this paper, a 2D SRG is proposed to form by periodically arranging slanted glass pillars on the surface of a glass waveguide, just like a photonic crystal. The structure can suppress all the other diffraction orders except the 0-order and the [1, 0] order. The best diffraction efficiency of the [1, 0] order can be obtained when the incident light is incident with not only an incident angle but also an azimuth angle. The geometric parameters of the pillars are investigated and optimized with the diffraction efficiency by the finite element method, and the relationship between the incident angles and the diffraction efficiency will also be discussed. The proposed structure has the potential in both the in-coupler and the out-coupler, respectively, for integrating light coming from different azimuth angles or for outputting light to different azimuth angles.

随着虚拟现实的发展，头戴式显示器（HMD）的投影设计也需要改进。表面浮雕光栅（SRG）是实现波导光引导的常用衍射元件之一。使用 SRG 作为耦合器，输入的信息光可以通过 1 阶衍射耦合到波导中。为了增加 HMD 的可能设计选项，具有复杂几何形状的 SRG 被设计为适合更多衍射条件。在本文中，提出了通过在玻璃波导表面周期性排列倾斜玻璃柱来形成2D SRG，就像光子晶体一样。该结构可以抑制除0级和[1, 0]级以外的所有其他衍射级。当入射光不仅以入射角入射而且以方位角入射时，可以获得最佳的[1, 0]级衍射效率。通过有限元方法研究并优化了柱体的几何参数和衍射效率，并讨论了入射角与衍射效率之间的关系。所提出的结构分别在输入耦合器和输出耦合器中具有用于集成来自不同方位角的光或用于将光输出到不同方位角的潜力。