Zheng Kezhi, Wang Lili, Zhang Daisheng, Zhao Dan, Qin Weiping
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China.
Opt Express. 2010 Feb 1;18(3):2934-9. doi: 10.1364/OE.18.002934.
Multiphoton upconversion (UC) emissions from the high-energy states ((4)G(9/2), (4)G(7/2), (2)K(13/2), and (2)P(3/2)) of Er(3+) ions were observed under 980 nm excitation. These high-energy excited states were populated by a five-photon or a four-photon UC process conditionally, which depended on the near-infrared (NIR) pump density. Experiments exhibited that the power dependence originated from the varied populating routes of intermediated (4)S(3/2) and (4)F(9/2) of Er(3+) under different NIR pump power. A mechanism of the power density-dependent multiphoton UC processes was proposed based on experimental data and analysis.
在980nm激发下，观察到了铒离子（Er(3+)）高能态（(4)G(9/2)、(4)G(7/2)、(2)K(13/2)和(2)P(3/2)）的多光子上转换（UC）发射。这些高能激发态通过五光子或四光子UC过程有条件地被填充，这取决于近红外（NIR）泵浦密度。实验表明，功率依赖性源于不同NIR泵浦功率下Er(3+)中间态(4)S(3/2)和(4)F(9/2)的不同填充路径。基于实验数据和分析，提出了一种功率密度依赖的多光子UC过程机制。
