Ultrabroadband Gain Characteristics of a Quantum-Dot-Doped Fiber Amplifier

In this paper, the energy level, transition configuration, and numerical model of a quantum dot (QD) doped fiber amplifier are presented using a two-level model for the first time. The results calculated using theoretical model are in good agreement with experimental results from literature. The rate and power propagation equations of the model are further solved to investigate the effects of the QD concentration, fiber length, ambient temperature, and pump power on bandwidth of the gain spectra; the results show that when pumped at 1200 nm, the fiber can have ultrabroad room-temperature gain spectra in the range 1.2-1.62 mum, which can utilize the low-loss bandwidth of the all-wave fiber without absorption peak caused by OH group.