# On‐Chip Silicon‐Based Micro‐Reflector Pixelated with Micro‐Light‐Emitting Diodes for Augmented Reality Projection Displays

## TL;DR

This paper introduces a new silicon-based micro-reflector device that improves the efficiency and directionality of micro-LEDs for augmented reality displays.

## Contribution

The paper introduces a scalable on-chip micro-reflector device that simultaneously enhances light extraction and beam shaping for µLEDs.

## Key findings

- The SMRD narrows emission divergence from ±70.5° to ±39.4°.
- Luminous flux within ±20° is enhanced by ∼64%.
- Pixel crosstalk is suppressed to 4.75%.

## Abstract

Augmented reality (AR) displays demand optical engines that are compact, efficient, and highly directional. While micro‐light‐emitting diodes (µLEDs) provide exceptional brightness, fast response, and low power consumption, their poor light extraction and near‐Lambertian emission severely limit optical coupling in AR systems. Here, we introduce a pixel‐by‐pixel on‐chip silicon‐based micro‐reflector device (SMRD) for µLEDs that simultaneously integrates light‐extraction enhancement and beam shaping within a scalable architecture. Simulation and experimental results show that the SMRD narrows the emission divergence from ±70.5° to ±39.4°, enhances luminous flux within ±20° by ∼64%, and suppresses pixel crosstalk to 4.75%. Beyond device‐level improvements, a near‐eye display prototype integrating the µLED/SMRD device with a projection lens, beam splitter, metal mask, and a camera acting as an eye substitute further verifies its system‐level performance. The SMRD thus delivers a compact and fabrication‐compatible route toward high‐efficiency, miniaturized AR projection engines. This work establishes a foundation for µLED‐based light‐field control, with implications for next‐generation near‐eye displays, spatial light modulators, and advanced photonic systems.

This paper presents a pixel‐by‐pixel on‐chip silicon‐based micro‐reflector device (SMRD) for µLEDs that enables simultaneous light‐extraction enhancement and directional emission control. The scalable architecture significantly improves forward light utilization and suppresses pixel crosstalk. System‐level validation in a near‐eye display prototype highlights its potential for compact, high‐efficiency AR optical engines.