Ultralow‐threshold wideband‐tunable single‐mode ultraviolet lasing from lanthanide‐doped upconversion nanomaterials

Abstract

Ultraviolet (UV) lasers with dynamic wavelength‐tunability and high monochromaticity are crucial in a multitude of practical applications yet still remarkable challenges. Here, we show wide wavelength‐tuning of single‐mode UV lasing based on lanthanide‐doped upconversion nanoparticles (UCNPs). The rationally designed Yb3+/Er3+/Tm3+/Gd3+/Ce3+ co‐doped multilayer UCNPs, which exhibits a broad gain spectrum with the full width of half maximum of around 57 nm in the UV regime, are developed. More importantly, by taking advantages of a diffraction grating as the tuning component, stable single‐mode emission can be achieved in the UCNPs‐based external‐cavity‐extended Fabry–Pérot laser at room temperature. Specifically, the lasing threshold is around 137 µJ cm–2, which is two orders of magnitude lower than that in the previously reported articles. Precise wavelength‐tuning from 310 to 363 nm can be realized by adjusting the Littrow angle. This achievement highlights a portable alternative to continuously wideband‐tunable UV lasers and opens up new opportunities for constructing compact solid‐state UV photon sources.

Micro- and nano-laser sensing: Principles and applications

“…薄方研究组 [72] 通过提出铌酸锂光子分子结 构实现了边模抑制比超过26 dB的单模激光出射. 对于 谐振模式丰富的微米级谐振腔, 可选择性泵浦特定模 式 [66] 或使用波长选择元件 [73] 等方式选择性激发或输 出特定波长的激光, 还可通过增加高阶模式的损耗从 而实现特定模式的激光出射 [74] .…”