Compensated DOE in a VHG-based waveguide display to improve uniformity

Area of Science:

• Optics and Photonics
• Display Technology
• Computer Science

Background:

• Augmented reality head-mounted displays (AR-HMDs) using diffractive waveguides are a key research area.
• Volume holographic grating (VHG) based waveguide displays often suffer from poor illuminance uniformity across the field of view (FOV).

Purpose of the Study:

• To propose and validate a high uniformity AR waveguide display system.
• To address the challenge of illuminance degradation at the edge FOV in VHG-based displays.

Main Methods:

• Analysis of angular uniformity in VHG-based waveguide displays.
• Integration of diffractive optical elements (DOEs) onto waveguide substrates for phase compensation.
• Development of a multi-objective stochastic gradient descent (MO-SGD) algorithm for DOE phase design.
• Application of a hybrid loss function incorporating the learned perceptual image patch similarity (LPIPS) metric.

Main Results:

• Simulation and experimental validation of the proposed high uniformity AR waveguide display.
• Suppression of illumination degradation at the edge FOV.
• Improvement in peak signal-to-noise ratio (PSNR) by 5.54 dB.
• Reduction in measured nonuniformity (NU) by 53.05% (from 0.3749 to 0.1760).

Conclusions:

• The proposed method effectively enhances illuminance uniformity in AR waveguide displays.
• Integrated DOEs and MO-SGD algorithm provide a viable solution for improving display quality.
• The approach demonstrates significant improvements in both simulated and experimental results, paving the way for better AR experiences.