硫系玻璃基掺铒微结构光纤4.5μm波段中红外信号放大特性

4.5 μm-band mid-IR amplifying characteristics of chalcogenide glass erbium-doped microstructured optical fiber

为进一步揭示硫系玻璃基掺Er3＋微结构光纤作为中红外光纤放大器增益介质的可行性，数值求解了800Bin泵浦波长下Ga5Ge20Sb10S65硫系玻璃基掺Er3＋微结构光纤中Er3＋离子数速率方程和光功率传输方程组，理论研究了4．5μm波段中红外信号的放大特性。结果显示，Ga5Ge20Sb10S65酯硫系玻璃基掺Er3＋微结构光纤具有较高的信号增益和很宽的增益谱。在50cm光纤长度上，最大信号增益超过了40dB，高于30dB信号增益的放大带宽达到了280am（4420～4700nm）。同时，进一步研究分析了4500nm波长信号增益与光纤长度、信号输入功率和泵浦功率的关系。研究表明，Ga5Ge20Sb10S65硫系玻璃基掺Er3＋微结构光纤是一种理想的可应用于4．5μm波段中红外宽带放大器的增益介质。

In order to demonstrate the feasibility of chalcogenide glass erbium-doped microstructured optical fiber （MOF） as a gain media applied in mid-infrared fiber amplifier, the numerical solving of the Er3＋ population rate equations and light power propagation equations of Ga5Ge20Sb10S65 chalcogenide glass erbium-doped MOF under 800 nm excitation were presented, and the amplifying characteristics of 4.5 μm- band mid-infrared signals were investigated theoretically. The results show that the chalcogenide glass erbium-doped MOF exhibits a higher signal gain and very broad gain spectrum, its maximum gain exceeds 40 dB and amplifying bandwidth above 30 dB gain reaches 280 nm（4 420-4 700 nm） on the 50 cm length of chalcogenide glass erbium-doped MOF. Moreover, the relations of 4 500 nm signal gain with fiber length, signal input power and pump power were studied and analyzed. The theoretical studies indicate that the Ga5Ge20Sb10S65 chalcogenide glass Er3＋ doped MOF is an excellent gain media which can be applied in broadband amplifiers in the mid-infrared wavelength region.