Framework for optimizing AR waveguide in-coupler architectures.

Area of Science:

• Optics and Photonics
• Display Technology
• Optical Engineering

Background:

• Waveguide displays suffer from light loss at the in-coupler diffractive surface, limiting overall system efficiency.
• Spatial variations in light loss across the beam degrade displayed image quality.
• Existing methods struggle to balance in-coupling efficiency with image quality.

Purpose of the Study:

• To present a framework for mitigating light losses in waveguide displays.
• To derive and quantify the tradeoff between in-coupling efficiency and Modulation Transfer Function (MTF).
• To introduce a novel in-coupler architecture that optimizes this tradeoff.

Main Methods:

• Developed a framework utilizing irradiance, efficiency, and MTF maps.
• Derived analytical expressions for the efficiency-MTF tradeoff.
• Designed and simulated a new in-coupler architecture using advanced computational methods.
• Compared computational speed against commercial non-sequential ray tracers.

Main Results:

• The proposed framework effectively alleviates losses and quantifies the efficiency-MTF tradeoff.
• The new in-coupler architecture mitigates the efficiency vs. image quality tradeoff.
• Demonstrated a 2,000x faster computation speed compared to commercial ray tracers.
• Achieved in-coupling efficiency meeting the fundamental limit and diffraction-limited MTF up to 30 cycles/deg (20/20 vision).

Conclusions:

• The developed framework provides a systematic approach to optimize waveguide display performance.
• The novel in-coupler architecture significantly enhances both efficiency and image quality.
• The computational speed enables rapid design exploration and optimization for future display technologies.