Maxwellian-View Augmented Reality Displays with Extended Depth of Field

Driven by the growing demand for enhanced visual interaction with the physical world, augmented reality (AR) display technologies have rapidly emerged as transformative interfaces, bridging digital information seamlessly with real-world environments. Conventional optical architectures—such as birdbath, freeform combiners, holographic optical elements (HOEs), and waveguide couplers—offer trade-offs in resolution, brightness, transparency, and field of view (FOV) but often suffer from accommodation mismatch and vergence–accommodation conflict (VAC), causing visual discomfort. Maxwellian-view or retina projection displays address these issues by projecting focused light bundles directly into the pupil, producing depth-invariant images that remain sharp regardless of the eye's accommodative state. This principle provides extended depth of field (DOF) and enables compact optical designs, though challenges such as a narrow eye-box remain. Recent advances—such as exit pupil expansion via multiple replications of converging points using HOE optics, beam splitter arrays, integration of holographic elements, and selective LED illumination—are enhancing the practicality of Maxwellian systems. By combining these with adaptive optics, intelligent tracking, and hybrid focal strategies, next-generation AR displays could deliver superior comfort, immersion, and usability. This review outlines the principles, advantages, limitations, and recent developments of Maxwellian AR optics, highlighting their potential as a transformative foundation for future AR display technologies across medical, industrial, and consumer applications.