Wang Xiangfu, Xiao Siguo, Bu Yanyan, Yang Xiaoliang, Ding J W
Institute for Nanophysics and Rare-Earth Luminescence, Xiangtan University, Xiangtan, China.
Opt Lett. 2008 Nov 15;33(22):2653-5. doi: 10.1364/ol.33.002653.
Visible IR-to-green photon-avalanche upconversion is reported in an Ho3+ singly doped beta-Na(Y1.5Na0.5)F6 crystal under 980 nm excitation. Upconverted green, red, and IR emissions are observed at 540, 645, and 751 nm, respectively. Temporal evolution and excitation power dependent upconversion intensity are measured, suggesting that a photon-avalanche mechanism is responsible for the upconversion process. It is believed that an efficient cross relaxation (5S2,5I8)-->(5I6,5I6) mainly performs the population of 5I6 excited state, resulting in the intense photon-avalanche upconversion emission in the synthesized samples.
据报道，在980nm激发下，Ho3+单掺杂的β-Na(Y1.5Na0.5)F6晶体中出现了可见红外到绿色的光子雪崩上转换。分别在540、645和751nm处观察到上转换绿色、红色和红外发射。测量了时间演化和与激发功率相关的上转换强度，表明光子雪崩机制是上转换过程的原因。据信，有效的交叉弛豫(5S2,5I8)-->(5I6,5I6)主要负责5I6激发态的布居，从而在合成样品中产生强烈的光子雪崩上转换发射。
