Quantification of upconversion photon and thermosensitive feedback in Er3+/Yb3+ doped fluorotellurite glasses

摘要

Multi-photon-excited green and red upconversion (UC) emissions have been quantified and adaptive temperature sensing performance has been investigated in Er3+/Yb3+ doped fluomtellurite (BZLFT) glasses under the excitation of 978 nm laser. The net emission photon numbers of H-2(11/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2) and F-4(9/2) -> I-4(15/2) transition emissions are identified to be 83.2 x 10(12) , 753.2 x 10(12) and 136.8 x 10(12) cps in 0.4 wt% Er2O3 -0.4 wt % Yb2O3 co-doping case under the excitation power density of 7.82 W/mm(2) . The quantum yields (QYs) and luminous fluxes for visible UC emissions of Er3+ are identified as a positive dependency with pumping powers. When the excitation power increases to 983 mW, the QYs for detected 526 and 545 nm green, and 658 nm red emissions are up to 0.155 x 10(-4) , 1.405 x 10(-4) and 0.255 x 10(-4 ), respectively. Low phonon-energy Er3+/Yb3+ doped BZLFT glasses with intense luminous efficiency can work steadily at medium temperature range in view of its fast responses and high stability, moreover, a maximum sensitivity reaches 4.77 x 10(-3 )K(-1) at 587.5 K, which indicates that the BZLFT glass material has a good thermal sensitivity. The macroscopic quantization for UC photon generation and the exploration of maximum sensitivity value from Er3+ in high transparent fluorotellurite glasses provide a reliable reference for developing optical temperature-sensing materials.