Wan Yuan, Wang Hongzhen, Li Hongwen, Ye Ruiqi, Zhang Xinyu, Lyu Jing, Cai Yangjian
Opt Express. 2022 Feb 28;30(5):8222-8233. doi: 10.1364/OE.451428.
In this article, we report a low-threshold random laser enhanced by TiN nanoparticles (NPs) suspended randomly in gain solutions. Results show that the random laser with TiN NPs has a lower threshold than the random laser with TiO NPs and the underlying mechanisms are discussed in detail. The localized surface plasmon resonance of individual TiN NPs increases the pump efficiency and strengthens the fluorescence amplification efficiency of the DCM. The multiple scattering of integral TiN NPs extends the dwelling time of light in random systems, which provides more possibilities for the light amplification in the gain medium. Then, the random laser threshold as a function of the number density of TiN NPs is studied. Results show that the optimum number density of TiN NPs for the lowest-threshold random lasers is about 1.468 × 10ml. When we substitute the ethanol solution with the nematic liquid crystal (NLC), the random laser threshold can be further decreased to 5.11 µJ/pulse, which is about 7.7 times lower than that of DCM dye solution with TiN NPs under the same conditions. These findings provide a cost-effective strategy for the realization of low-threshold random lasers with high-quality.
在本文中，我们报道了一种通过随机悬浮在增益溶液中的氮化钛纳米颗粒（NPs）增强的低阈值随机激光器。结果表明，含有氮化钛纳米颗粒的随机激光器阈值低于含有二氧化钛纳米颗粒的随机激光器，并对其潜在机制进行了详细讨论。单个氮化钛纳米颗粒的局域表面等离子体共振提高了泵浦效率，并增强了二氯甲烷的荧光放大效率。整体氮化钛纳米颗粒的多次散射延长了光在随机系统中的停留时间，这为增益介质中的光放大提供了更多可能性。然后，研究了随机激光阈值作为氮化钛纳米颗粒数密度的函数。结果表明，实现最低阈值随机激光器的氮化钛纳米颗粒的最佳数密度约为1.468×10ml。当我们用向列型液晶（NLC）替代乙醇溶液时，随机激光阈值可进一步降低至5.11µJ/脉冲，在相同条件下，这比含有氮化钛纳米颗粒的二氯甲烷染料溶液的阈值低约7.7倍。这些发现为实现高质量低阈值随机激光器提供了一种经济高效的策略。
