Dynamic eyebox expansion in holographic near-eye displays via active switching quarter-waveplate geometric phase prisms

This study presents a dynamic eyebox expansion method in holographic near-eye displays (H-NEDs) using bi-stacked, actively switchable geometric phase prisms (GPPs) with quarter-waveplate (QWP) retardation. Orthogonally oriented QWP-GPPs independently steer beams in two dimensions, forming nine discrete exit pupils in a 3×3 array. Temporal polarization multiplexing activates a single pupil at a time, ensuring high efficiency and effectively suppressing inter-pupil crosstalk. Integrated with gaze tracking, the system dynamically aligns the active viewpoint with the user’s gaze, improving alignment tolerance and visual comfort. Experiments validate 12 mm ×12 mm eyebox expansion and ∼13.4° diagonal field-of-view (FOV) per viewpoint, proving compact, user-adaptive H-NED feasibility.