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

Area of Science:

• Optics and Photonics
• Optical Engineering

Background:

• Designing compact collimating lens systems for augmented reality (AR) applications faces significant optical challenges.
• Existing solutions often struggle to balance field of view, optical performance, and device size.

Purpose of the Study:

• To present a novel, compact collimating lens system for lightguide-based AR glasses.
• To optimize the design for a 0.32-inch microdisplay, enhancing the trade-off between field of view, optical quality, and miniaturization.

Main Methods:

• Optical design utilizing four plastic aspherical lenses.
• Design tailored for a 0.32-inch microdisplay.
• Analysis of key optical parameters including F-number, distortion, and modulation transfer function (MTF).

Main Results:

• Achieved a 50-degree field of view with an F-number of 2.17 and a 4 mm entrance pupil diameter.
• Optical distortion is below 0.29%, and MTF exceeds 0.23 at 250 cycles/mm.
• The system boasts a compact volume of 0.93 cm³ and a mass of 1.08 g, with overall dimensions of 10.16 mm diameter and 11.48 mm length.

Conclusions:

• The proposed collimating lens system offers significant improvements in size and weight reduction for AR glasses.
• Demonstrates a practical and manufacturable solution for next-generation AR eyewear, enhancing optical performance.
• Represents an innovative contribution to the optical design of AR devices.