近日，华南理工大学的董国平及其研究小组与哈尔滨工程大学的任晶等人合作并取得一项新进展。经过不懈努力，他们在稀土激活的玻璃中纳米晶微腔中实现稳健的低阈值全彩上转换激射。相关研究成果已于2025年1月2日在国际知名学术期刊《光：科学与应用》上发表。

本文报道了一种批量生产的纳米玻璃复合（GC）微球，其中嵌入了掺稀土氟化物纳米晶体，该微球展现出高效的上转换（UC）发光。这些多相复合微球具有高达10⁵的品质因数（Q值），与传统多组分玻璃微球相当。基于高效的锥形光纤-微球系统，研究人员实现了纯红、绿、蓝（RGB）三原色的上转换激射。更重要的是，GC微球表现出更低的激射阈值（降低了45%）和更高的斜率效率（提高了四倍以上）。这些特性，加上其优异的长期稳定性，为实现高度稳健、独立、低阈值和多功能的上转换微激光器提供了有前景的解决方案。

据悉，可见光微激光器是集成光子学的基本构建模块。然而，由于在短波长下实现粒子数反转的要求极为苛刻，因此在室温（RT）下实现低阈值（微瓦级）、连续波（CW）可见光激射一直是一项挑战。稀土（RE）激活的微腔具有高品质因数（Q）和回音廊模式的小模式体积，为实现红外至可见光的上转换（UC）激射提供了绝佳机遇。

附：英文原文

Title: Robust low threshold full-color upconversion lasing in rare-earth activated nanocrystal-in-glass microcavity

Author: Gao, Zhigang, Cui, Lugui, Chu, Yushi, Niu, Luyue, Wang, Lehan, Zhao, Rui, Yang, Yulong, Liu, Xiaofeng, Ren, Jing, Dong, Guoping

Issue&Volume: 2025-01-02

Abstract: Visible light microlasers are essential building blocks for integrated photonics. However, achieving low-threshold (μW), continuous-wave (CW) visible light lasing at room temperature (RT) has been a challenge because of the formidable requirement of population inversion at short wavelengths. Rare-earth (RE)-activated microcavities, featuring high-quality factor (Q) and small mode volume of whispering gallery modes, offer a great opportunity for achieving infrared-to-visible upconversion (UC) lasing. Here, we report that batch-produced nano-glass composite (GC) microspheres incorporating RE-doped fluoride nanocrystals show efficient UC emissions. These multi-phase composite microspheres exhibit a high Q value (≥10⁵), comparable to that of conventional multi-component glass microspheres. The UC lasing with pure red, green, and blue (RGB) emissions are demonstrated based on a highly efficient tapered fiber-microsphere system. More importantly, the GC microspheres manifest reduced (by 45%) lasing threshold and enhanced (more than four times) slope efficiency. These characteristics, together with excellent long-term stability, suggest a promising solution to achieving highly robust, stand-alone, low-threshold, and versatile UC microlasers.

DOI: 10.1038/s41377-024-01671-3

Source: https://www.nature.com/articles/s41377-024-01671-3