Evanescent wave coupled semiconductor quantum dots fiber amplifier based on reverse micelle method

A novel optical fiber amplifier based on interacting between semiconductor quantum dots luminescence and fiber evanescent wave was proposed in this paper. This fiber amplifier, named here as semiconductor quantum dots amplified fiber (SQDAF), was fabricated by depositing PbS quantum dots on a fused tapered optical evanescent wave fiber coupler. The simple reverse micelle method was applied here to synthesize the PbS quantum dots. By optimizing the synthesis procedure, the size of the PbS particles was controlled and their solution exhibited obvious photoluminescence blue shift effect which was observed by fluorescent spectrometer. The optical gain was characterized and more than 4dB was obtained at 1310 nm with only 5 cm interacting length. Simultaneously the saturation effect was also investigated theoretically and experimentally. This compact and highly efficient quantum dots fiber amplifier has potential applications in high-speed broadband CATV and access networks.