Controllable synthesis of β-NaLuF4:Yb3+, Er3+ nanocrystals and their application in polymer-based optical waveguide amplifiers

Abstract

Abstract Hexagonal structured NaLuF4 (β-type) nanocrystals (NCs) with controllable particle size were prepared by thermal decomposition approach. The as-prepared NCs possessed good dispersibility in organic solvents. Under a 980 nm laser excited, these Er3+ and Yb3+ co-doped β-NaLuF4 NCs demonstrated emission around 1530 nm. These β-NaLuF4:Yb3+, Er3+ NCs were dispersed into SU-8 polymer to fabricate polymer waveguides, and the results showed that their crystal size influenced greatly on the performance of polymer waveguides. The relative optical gain of 2.413 dB, 1.653 dB and 0.481 dB at 1530 nm was achieved when the particle size was about 8 nm, 15 nm, and 23 nm, respectively. These results show that β-NaLuF4:Yb3+, Er3+ NCs with small particle size were promising materials for building Er3+-doped polymer-based optical waveguide amplifiers.