Open AccessPOPULATION BRANCHING RATIO MODEL——AN EFFECTIVE QUALITIVE ANALYSIS METHOD ABOUT UP-CONVERSION EFFICIENCY
Author(s) -
Xiaobo Chen,
Meng Chao,
Yafei Wang,
Hui Ma,
Meixian Li
Publication year - 2000
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.49.1176
Subject(s) - metastability , branching fraction , excited state , branching (polymer chemistry) , population , materials science , branching process , phonon , relaxation (psychology) , radiative transfer , rate equation , energy conversion efficiency , atomic physics , physics , optics , statistical physics , optoelectronics , condensed matter physics , quantum mechanics , kinetics , sociology , demography , composite material , psychology , social psychology
This article analyze the physics of up-conversion process excited by CW laser. The key metastable state is very important because it initiates the up-conversion process.By analyzing the dynamic process of the key metastable state, a qualitative “population branching ratio β” model is proposed. The physical significance of this method is that it helps to understand the general characteristics of up-conversion.Further analysis indicates, spontaneous emission and non-radiative relaxation Wn do act simultaneously.And the reason why the up-conversion fluorescence of quartz,pentaphosphate non-crystalline is about ten thousand times smaller than that of fluoride glass is that their multi-phonon nonradiative relaxation rate n is much larger than the spontaneous emission rate . We also report the benefit value and the condition WnA of phonon for up-conversion.