Gain characteristics of quantum dot fiber amplifier based on asymmetric tapered fiber coupler

► Propose compact and evanescent wave pumped optical amplifier based on an asymmetric tapered fiber coupler coated with active quantum dot layer. ► Theoretical analysis of the gain characteristics of PbS quantum dot (QD) fiber amplifier. ► 10 dB gain of a 1550-nm signal expected with the gain efficiency of 4.5 dB/cm.