Enhancing environmental stability of a PbS quantum dot optical fiber amplifier via rational interface design

A PbS quantum dot optical fiber amplifier with enhanced processability and environmental stability is described. Modification of PbS quantum dots with multifunction copolymers was demonstrated via spectroscopy to aid dispersion of the quantum dots in a sol during the fabrication of a quantum dot optical fiber amplifier without degradation or modification of optical properties. The influence of multifunction copolymers and oleylamine-coated PbS quantum dots on the structure was studied via scanning electron microscopy. The nanoparticle shape of oleylamine-coated PbS quantum dots after polymer modification remained unchanged compared to those previously reported. With the addition of a fluorine-containing component, a PbS quantum dot optical fiber amplifier retained 96% of its initial gain after 100 days, as compared with 16% for quantum dots modified with a non-fluorine-containing polymer, it was certain that fluorine bond of multifunction copolymers had a good improvement in durability of PbS quantum dot. Simultaneously, PbS quantum dot optical amplifier gain as high as 17 dB was achieved at 1550 nm.