# A Single-Layer Full-Color Diffractive Waveguide by Lithography

## TL;DR

This paper introduces a scalable method to produce single-layer full-color diffractive waveguides for augmented reality displays.

## Contribution

A DUV lithography-based workflow for mass-producing nanostructured optics in AR waveguides is proposed.

## Key findings

- A scalable DUV lithography workflow enables wafer-level production of nanostructured optics.
- A single-layer diffractive waveguide achieves full-color performance with high efficiency.
- RCWA and ray tracing improve diffraction and light uniformity in the waveguide design.

## Abstract

Augmented reality (AR) near-eye displays (NEDs) couple microdisplay image light to the human eye via integrated optical modules, enabling seamless virtual–real fusion. As core components that synergistically transmit and diffract light, diffractive waveguides are promising for next-generation AR NEDs but face two bottlenecks: compromised full-color performance in single-layer structures caused by grating dispersion and lack of scalable fabrication technologies. To address these, we first propose a mass-production-compatible workflow based on deep ultraviolet (DUV) lithography for large-area nanostructured optics. This workflow enables high-precision wafer-level production with 200 mm wafers and nine dies per wafer, overcomes scalability issues, and is fully compatible with straight-configuration nanostructures to ensure manufacturing feasibility. Leveraging this workflow, we develop a single-layer diffractive waveguide system for AR NEDs, which comprises a thin glass substrate, a broadband high-efficiency multi-layer dielectric in-coupler, and a 2D out-coupler that concurrently expands and out-couples light. Rigorous coupled wave analysis (RCWA) optimized coupler diffraction, while ray tracing refined guided light intensity and significantly improved exit pupil uniformity. This work establishes a foundation for full-color, high-efficiency AR waveguides and provides a scalable paradigm for large-area nanostructured optical systems such as telescopes and lithography equipment.