On-Demand Control of Lanthanide Optical Dynamics via Pumping-Flux Modulation.

Guo, Dan; Pang, Xuewen; Liu, Chang; Li, Yixuan; Chen, Jiaye; Zhai, Tianrui; Liang, Liangliang; Liu, Xiaogang · Nano Lett · 2025

basic_science · Level V

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Abstract

Precise control of lanthanide luminescence decay is essential for the development of emerging nanophotonic applications. However, existing strategies rely on static material modifications. Here, we introduce a pumping-flux modulation strategy that enables reversible, on-demand tuning of luminescence lifetimes via direct control of the cross-relaxation processes. Using highly Er<sup>3+</sup>-doped nanocrystals, we demonstrate that adjusting excitation pulse duration and intensity enables over 10-fold tuning in green (from 47.3 to 537.1 μs) and near-infrared (1506.4 to 145.5 μs) emissions. Mechanistic studies reveal that excitation profile modulation alters the populations of ground and intermediate energy states, which, in turn, influences cross-relaxation pathways and emission kinetics. We further demonstrate dynamically programmable lifetime mapping for optical encryption, eliminating the need for complex materials engineering. This work introduces a fundamentally new route for controlling lanthanide emission in real time with broad implications for adaptive displays, reconfigurable photonics, and time-domain optical security.