The characteristic saturation phenomenon of upconversion luminescence in holmium–ytterbium-co-doped oxyfluoride glass Ho(0.1)Yb(5):FOG

• Published in: Physica. B, Condensed matter Condensed matter, 2008-11, Vol.403 (21), p.3847-3852
• Main Authors: Chen, Xiaobo, Song, Zengfu, Sawanobori, Naruhito, Ohtsuka, Masaaki, Li, Xiaowen, Wang, Yafei, Xu, Xiaoling, He, Chenjuan, Ma, Hui, Chen, Ying, Zhu, Jianyang
• Format: Article
• Language: English
• Subjects: Amorphous materials, glasses and other disordered solids; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Energy expansion; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Oxyfluoride glass; Photoluminescence; Physics; Upconversion luminescence
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2008.05.003

The upconversion luminescence of holmium Ho 3+ ion sensitized by ytterbium Yb 3+ ion in Ho 3+Yb 3+-co-doped oxyfluoride glass Ho(0.1)Yb(5):FOG is investigated in this paper. A plenty of upconversion luminescence lines are measured out. The upconversion mechanism of Ho(0.1)Yb(5):FOG, when excited by 960 nm laser, is the energy transfer from Yb 3+ to Ho 3+ ion. A very weak 795.5 nm common photoemission fluorescence is detected, which is recognized as the 5I 4→ 5I 8 fluorescence transition based on careful measurement, calculation and analysis. And moreover, a novel characteristic upconversion luminescence saturation phenomenon is found. It is that the log F–log P curve of upconversion fluorescence vs. pumping laser power is a straight line, and meanwhile the slopes of these double-logarithmic F– P plots are smaller than normal multi-photon relation clearly. When pumping laser spot is increased, the slopes of these double logarithmic F– P plots could be enhanced noticeably from small value to near the normal multi-photon relation value. The mechanism of this characteristic saturation phenomenon is the energy expansion resulted from energy resonant migration among Yb 3+ ions.