Amplification properties of Tb (III) green emission in polymeric waveguide doped with Tb–Al nanocluster

This paper describes optical amplification properties in a polymeric waveguide doped with Tb–Al nanoclusters. The Tb–Al nanocluster is a promising fluorescent material for polymeric waveguides, which can be uniformly dispersed in polymer matrices while restraining the concentration quenching of Tb3+. Under the continuous optical pumping by 488 nm laser light, optical amplification for the green emission of Tb3+ was achieved. The optical gain coefficients were estimated to be as high as 0.25 and 0.56 mm−1 at the Tb–Al nanocluster concentrations of 4.5 and 5.0 wt%, respectively. Taking into account our previous works for the polymeric waveguide doped with Eu–Al nanocluster, the rare-earth-metal nanocluster is believed to be a promising candidate for various photonic applications such as multicolor polymer lasers and waveguide-type optical amplifiers.