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

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

doi:10.1038/s41377-024-01671-3

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

Light Sci Appl. 2025 Jan 2;14(1):14. doi: 10.1038/s41377-024-01671-3.

Authors

Zhigang Gao¹, Lugui Cui², Yushi Chu², Luyue Niu², Lehan Wang², Rui Zhao¹, Yulong Yang², Xiaofeng Liu³, Jing Ren⁴, Guoping Dong⁵

Affiliations

¹ College of Physics and Electronic Engineering, Taishan University, 271021, Taian, China.
² Key Laboratory of In-fiber Integrated Optics of Ministry of Education, College of Physics and Optoelectronic Engineering, Harbin Engineering University, 150001, Harbin, China.
³ School of Materials Science and Engineering, Zhejiang University, Hangzhou, China.
⁴ Key Laboratory of In-fiber Integrated Optics of Ministry of Education, College of Physics and Optoelectronic Engineering, Harbin Engineering University, 150001, Harbin, China. [email protected].
⁵ State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Engineering, South China University of Technology, 510640, Guangzhou, China. [email protected].

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.

Abstract

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