Compact Design of a 50° Field of View Collimating Lens for Lightguide-Based Augmented Reality Glasses

Designing a compact collimating lens system for augmented reality (AR) applications presents significant optical challenges. This paper presents a compact, 50-degree field-of-view collimating lens system explicitly designed for lightguide-based AR glasses. The compact collimating lens is designed for a 0.32-inch microdisplay and consists of four plastic aspherical lenses. The optical design results in a collimating lens with a F-number of 2.17 and an entrance pupil diameter of 4 mm. Optical distortion is less than 0.29%, and the modulation transfer function (MTF) is greater than 0.23 at 250 cycles/mm. The overall lens diameter, including the lens barrel, measures 10.16 mm, while the lens length is 11.48 mm. The lens volume is 0.93 cm3, and its mass is 1.08 g. Compared to existing collimator designs, this approach significantly improves the trade-off between field of view, optical quality, and device miniaturization. The proposed design supports integration with 0.32-inch microdisplays, making it a practical and manufacturable solution for next-generation AR eyewear. This paper presents innovative contributions to the optical design of AR glasses, demonstrating considerable potential in reducing size and weight, and optimizing optical performance.