Excitation power-dependent multicolor upconversion in NaLnF4:Er3+ under 1532 nm irradiation for anti-counterfeiting application
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Published:2024-05-22
Issue:11
Volume:49
Page:2978
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ISSN:0146-9592
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Container-title:Optics Letters
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language:en
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Short-container-title:Opt. Lett.
Author:
You Wenwu,Zhang Chennan,Yu Ruoxi,Zhang Xiaomin,Li Jiacai,Li Mingxing,Xu Zhili,Fan Pingping,Pan Gencai,Mao Yanli
Abstract
Upconversion (UC) materials are renowned for their ability to convert low-energy photons into high-energy ones. The manipulation of parameters allows for the observation of multicolored UC luminescence (UCL) within a single material system. While modulation of multicolored UCL commonly relies on excitation at approximately 980 nm, investigation into multicolored UC materials activated by a 1532 nm excitation source remains comparatively scarce. In this work, we introduce NaLnF4:Er3+ as a novel class of smart luminescent materials. When the power density of a 1532 nm laser increases from 0.5 to 20.0 W/cm2, the emission peak positions remain unchanged, but the red-to-green (R/G) ratio decreases significantly from 18.82 to 1.48, inducing a color shift from red to yellow and ultimately to green. In contrast, no color variation is observed when NaLnF4:Er3+ is excited with a 980 nm laser at different power densities. This power-dependent multicolored UCL of NaLnF4:Er3+ excited at 1532 nm can be attributed to the competitive processes of upward pumping and downward relaxation of electrons on the 4I9/2 level of Er3+. By utilizing the unique UC characteristics of NaLnF4:Er3+, its potential utility in anti-counterfeiting applications is demonstrated. Our research highlights the distinctive optical properties of NaLnF4:Er3+ and provides novel insights into the use of luminescent materials in optical anti-counterfeiting technologies.
Funder
National Natural Science Foundation of China
China Postdoctoral Science Foundation
Natural Science Foundation of Henan Province
Project for Scientific and Technological Innovation Team of Universities in Henan Province
Key Project for the Scientific Research of Universities in Henan Province
Publisher
Optica Publishing Group