掺铒硫系玻璃的制备及其微结构光纤的中红外信号放大特性研究

为进一步揭示硫系玻璃基掺Er³⁺微结构光纤对于中红外波段信号的放大特性, 采用熔融淬火法研制了Er³⁺离子掺杂的Ga₅Ge₂₀Sb₁₀S₆₅硫系玻璃, 测试了玻璃样品的吸收光谱和2.7 μm波段荧光光谱, 利用Judd-Ofelt和Futchbauer-Ladenburg理论分别计算得到了Er³⁺离子的辐射跃迁概率、辐射寿命以及2.7 μm波段受激发射截面. 在此基础上, 建立了一个980 nm抽运下该玻璃基掺Er³⁺微结构光纤2.7 μm波段中红外信号的放大模型, 理论上研究了其作为2.7 μm波段中红外信号增益介质时的光放大特性. 结果显示, 硫系玻璃基掺Er³⁺微结构光纤具有优异的高增益和宽带放大品性. 在200 mW抽运功率激励下的100 cm光纤长度上, 最大小信号增益超过了40 dB, 高于30 dB信号增益的放大带宽达到了120 nm (2696—2816 nm). 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2.7 μm波段中红外宽带放大器的增益介质.

Fabrication of erbium-doped chalcogenide glass and study on mid-IR amplifying characteristics of its microstructured fiber

In order to demonstrate the characteristics of chalcogenide glass Er³⁺-doped microstructured optical fiber（MOF） amplifying the mid-infrared band signal,Er³⁺-doped Ga₅Ge₂₀Sb₁₀S₆₅ chalcogenide glass is prepared with high temperature melt-quenching method. The absorption spectrum and 2.7μm band fluorescence spectrum of glass sample are measured,and the spectroscopic parameters such as radiative transition probability,radiative lifetime and 2.7μm band stimulated emission cross-section of Er³⁺ ion are calculated and analyzed according to the Judd-Ofelt and Futchbauer-Ladenburg theories.The 2.7μm band mid-infrared signal amplifying model of Ga₅Ge₂₀Sb₁₀S₆₅ chalcogenide glass Er³⁺-doped MOF under the excitation of 980 nm is presented,and the amplifying characteristics of 2.7 mn-band mid-infrared signals for chalcogenide glass Er³⁺-doped MOF are investigated theoretically.The results show that the chalcogenide glass Er³⁺-doped MOF exhibits a higher signal gain and very broad gain spectrum:its maximal gain of small signal exceeds 40 dB and amplifying bandwidth of higher than 30 dB gain reaches about 120 nm（2696—2816 nm） for a 100 cm long chalcogenide glass erbium-doped MOF with a pump power of 200 mW.The theoretical studies indicate that the Ga₅Ge₂₀Sb₁₀S₆₅ chalcogenide glass Er³⁺-doped MOF is an excellent gain medium which can be applied to broadband amplifiers in the mid-infrared wavelength region.