State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China.
Opt Lett. 2010 Jul 15;35(14):2442-4. doi: 10.1364/OL.35.002442.
We observed multiphoton upconversion (UC) emissions from the high-energy states ((2)I(11/2), (4)D(7/2), (4)G(9/2), (2)D(5/2), (2)K(13/2), and (2)P(3/2)) of Er(3+) ions in Yb(3+)-Er(3+) codoped beta-NaYF(4) microcrystals under 1560 nm excitation. Analysis indicated that the highest-order emissions came from 11-photon UC processes. In the codoped system, the energy transfer (ET) from Er(3+)((4)I(11/2)) to Yb(3+)((2)F(5/2)) and subsequently the back ET from Yb(3+) to Er(3+) played important roles in populating these high-energy states of Yb(3+) and Er(3+). Several different UC processes work simultaneously to populate excited Er(3+) in this codoped sample.
我们观察到掺铒和掺镱的β-氟化钠（β-NaYF4）微晶体中，铒离子（2I11/2、4D7/2、4G9/2、2D5/2、2K13/2 和 2P3/2）高能态的多光子上转换（UC）发射，激发光为 1560nm。分析表明，最高阶发射来自于 11 光子 UC 过程。在共掺体系中，铒离子（4I11/2）到镱离子（2F5/2）的能量传递（ET）以及随后镱离子到铒离子的反向 ET，在填充这些 Yb3+和 Er3+的高能态中起重要作用。在这个共掺样品中，几个不同的 UC 过程同时作用来填充激发态的铒离子。
