Suppressing optical crosstalk in microLED arrays for AR displays: a simulation and design study

Area of Science:

• Optoelectronics
• Display Technology
• Nanophotonics

Background:

• Augmented reality (AR) displays require MicroLEDs with high light extraction efficiency (LEE) and directionality.
• Optical crosstalk in MicroLEDs degrades image quality, necessitating effective suppression strategies.

Purpose of the Study:

• To develop a simulation framework for investigating crosstalk suppression in MicroLEDs for AR.
• To introduce and utilize collimation efficiency (CE) as a key metric for AR system performance.

Main Methods:

• Utilized finite-difference time-domain (FDTD) simulations to model MicroLED device architectures.
• Investigated the impact of device modifications, including n-GaN layer thinning and reflective cups, on crosstalk.
• Simulated the effect of a microlens layer on enhancing collimation efficiency.

Main Results:

• A thinned n-GaN layer with a reflective cup effectively eliminated primary crosstalk from sidewalls and waveguiding.
• The optimized architecture, including a thick microlens layer, achieved a collimation efficiency (CE) of 15.57%.
• The effective optical crosstalk was reduced to a minimal 0.77%.

Conclusions:

• The proposed device architecture offers an effective strategy for crosstalk suppression in MicroLEDs for AR displays.
• Achieving low crosstalk and high CE is crucial for enhancing AR image quality.
• This simulation-driven approach provides a pathway for designing next-generation AR display technologies.