In this paper, the gain engineering of a semiconductor quantum dots fiber amplifier (SQDFA) is studied. The optical amplification is realized by exciting the PbS quantum dots coated around the tapered single-mode fiber coupler with an evanescent wave. The gain spectra and saturation properties of the SQDFA are obtained via solving the rate and coupled power equations based on the two-level model. Then, the effect of the signal wavelength, pump power and amplifier length on the saturation characteristics is numerically simulated. The obtained results show that the proposed model is in a good agreement with the previous experimental results. Unique characteristics of the SQDFA such as the broadband optical gain and smooth bandwidth are of great interest for dense wavelength-division multiplexing systems. Therefore, the proposed model show promising applications in the future fiber-optic communications.

本文研究了半导体量子点光纤放大器（SQDFA）的增益工程。通过用van逝波激发围绕锥形单模光纤耦合器的PbS量子点来实现光放大。通过基于两级模型求解速率和耦合功率方程，可以获得SQDFA的增益谱和饱和特性。然后，数值模拟了信号波长，泵浦功率和放大器长度对饱和特性的影响。所得结果表明，所提出的模型与以前的实验结果吻合良好。SQDFA的独特特性，例如宽带光增益和平滑带宽，对于密集的波分复用系统非常重要。所以，