Gaze-matching eyebox expansion in retinal projection augmented reality display

Eyebox expansion of retinal projection-based augmented reality display may lead to image deviation from the fovea of the human eye. Hence, this paper proposes an eyebox-extended retinal projection display (RPD) with gaze-matching for augmented reality. The system's exit pupil is a composite image combiner composed of three holographic optical elements (HOEs). Each HOE is positioned at a specific location on the waveguide, allowing the diffracted beams to be imaged on the fovea of the human eye. Gaze-matching is achieved. In the experiment, the RPD systems of the traditional structure and proposed structure were both established in Zemax software for simulation. A detector was added at the retinal position for the comparison of the light distribution when viewing from different viewpoints. Optical experiments were also conducted to record the distribution of light on the receiving screen and observe the display performance of the proposed system. Both simulation and optical experiments show that the proposed system has the ability to project virtual images onto the fovea of the human eye to achieve gaze-matching.