Lanthanide-activated nanoconstructs for optical multiplexing

Lanthanide-activated nanoconstructs (LANCs) have attracted a great attention in optical multiplexing. This review, is the integrated conclusion of reported LANCs being applied as signal codes in optical multiplexing during the past decade. An introduction of the basic concepts and theories about optical multiplexing technique is provided initially. On top of that, the optical advantages of LANCs is comprehensively summarized to illuminate the superiority of LANCs over conventional materials in optical multiplexing. It particularly focuses on the near-infrared (NIR) light excited upconversion (UC) and downshifting (DS) nanomaterials, concerning their diverse and narrow excitation and emission wavelengths, tunable emission lifetime (mu s-ms range) and intensity. Subsequently, the exploitation of UCor DS-emitting LANCs as encoding tools in multiplexing based on various optical parameters is described in detail, including emission wavelength, intensity (ratiometric), temporal lifetime (tau), phase angle and excitation power. Notably, these parameters can not only work by themselves to be encoders, but also ally with each other to remarkably enrich the encoding capability of LANCs. In addition, the attractive dual-modal DS and UC emission-based multiplexing is emphasized. Finally, a summary of the challenges faced by LANCs-based optical multiplexing and a discussion of their future development is given. (C) 2020 Elsevier B.V. All rights reserved.