Ultra-directional and high-efficiency µLEDs via gradient index filled micro-horn collimators
摘要
Micro-LEDs (µLEDs) are poised to transform near-eye AR/VR, display, and optical communication technologies, but they are currently hindered by low light extraction efficiency and non-directional emission. Our study introduces an innovative approach using a descending index multilayer anti-reflection coating combined with a horn collimator structure atop the µLED pixel. This design leverages the propagation of light outside the critical angle to enhance both the directionality and extraction efficiency of emitted light. By implementing either discrete or continuous refractive index gradients within the horn, we achieve a tenfold increase in light extraction within a