Sitong Yao, Jian Kang, Guang Rui Zhang, Yun Sheng Hu, Zhen Yan, Wieslaw Strek, Robert Andrzej Tomala, Mariusz Stefanski, Vladimir Vasilyevich Osipov, Roman Nikolaevich Maksimov, Pande Zhang, Hao Chen, Le Zhang
LuAG:Ce ceramics suffer from total internal reflection (n ≈ 1.8), limiting light extraction. We fabricate periodic microstructures via nanoimprint lithography (NIL) and inductively coupled plasma (ICP) etching. A polymer micropillar array (period 3 μm, height 2.5 μm) is transferred into the ceramic (BCl3/CHF3, 5500 s), forming conical and concave structures. Under 450 nm laser excitation, the concave structure achieves >50% higher luminous efficacy, a broader beam angle (146.6° versus 129.1°), and a lower operating temperature (85.8°C versus 72.8°C versus 65.9°C) than a planar reference. Emission spectra, color temperature, and chromaticity coordinates remain unchanged, confirming that the enhancement originates from improved outcoupling. This NIL-ICP strategy offers a scalable route to boost efficiency and thermal reliability for next-generation laser lighting and displays.