中红外7×1硫化物光纤合束器的设计与制备

硫化物光纤合束器可以实现对多个中红外光源(2～5μm)的功率组合和光谱扩展,基于自研As₂S₃多模光纤,使用低温熔融拉锥技术制备得到7×1中红外光纤合束器,分析了拉锥区域的损耗产生机理,并表征和评估了合束器的传输效率和光束质量。实现了输入光纤合束端与输出光纤的高质量熔接(熔接点损耗低至0.45 dB,抗拉张力超过300 g),合束器平均传输效率约为80%,单通道最高输出功率为4.32 W,表现出了优良的传输特性和功率承载能力。     

超低损耗硫系光纤制备与中红外激光传输性能

硫系玻璃作为一种优秀的红外材料,具有透过范围广、物化性能稳定、易于成纤等特点,是制备红外传能光纤的理想材料之一。从硫系玻璃吸收损耗抑制和散射损耗抑制两方面入手,采用气（氯气）/气（玻璃蒸汽）、固（铝）/液（玻璃熔液）化学反应除杂方式降低光纤吸收损耗,建立了三维激光显微成像系统,检测玻璃及光纤内部的微米和亚微米量级的缺陷,优化制备工艺降低光纤散射损耗,制备出损耗为0.087 dB/m(@4.778μm)的硫系玻璃光纤。分别利用光纤激光器（波长为2.0μm）和双波长输出的光学参量振荡器（OPO）激光器（波长为3.8μm和4.7μm）进行激光传能实验,在单模光纤和多模光纤中分别实现了6.10 W(@2.0μm)和6.12 W(@3.8μm和4.7μm)激光传输。     

Structural evolution study of additions of Sb_2S_3 and CdS into GeS_2 chalcogenide glass by Raman spectroscopy

The structures of pseudo-binary GeS_2–Sb_2S_3, GeS_2–CdS, Sb_2S_3–CdS, and pseudo-ternary GeS_2–Sb_2S_3–CdS chalcogenide systems are systematically investigated by Raman spectroscopy. It is shown that a small number of [S_3Ge–GeS_3]structural units(SUs) and-S-S-/S8 groups exist simultaneously in GeS_2 glass which has a three-dimensional continuous network backbone consisting of cross-linked corner-sharing and edge-sharing [GeS_4] tetrahedra. When Sb_2S_3 is added into GeS_2 glass, the network backbone becomes interconnected [GeS_4] tetrahedra and [SbS_3] pyramids. Moreover, Ge atoms in[S_3Ge–GeS_3] SUs tend to capture S atoms from Sb_2S_3, leading to the formation of [S_2Sb–SbS_2] SUs. When CdS is added into GeS_2 glass, [Cd_4GeS_6] polyhedra are formed, resulting in a strong crystallization tendency. In addition, Ge atoms in[S_3Ge–GeS_3] SUs tend to capture S atoms from CdS, resulting in the dissolution of Ge–Ge bond. Co-melting of Sb_2S_3 or CdS with GeS_2 reduces the viscosity of the melt and improves the homogeneity of the glass. The GeS_2 glass can only dissolve up to 10-mol% CdS without crystallization. In comparison, GeS_2–Sb_2S_3 glasses can dissolve up to 20-mol% CdS,implying that Sb_2S_3 could delay the construction of [Cd_4GeS_6] polyhedron and increase the dissolving amount of CdS in the glass.     

基于下陷内包层设计的大芯径掺氟光纤表征及性能

采用体式显微镜、扫描电子显微镜、拉曼光谱表征了不同氟浓度、波导结构条件下光纤预制棒锥区及光纤的表面形貌与微观结构,用光纤综合参数分析仪、自制输出激光刀头分析了大芯径掺氟包层光纤的损耗、激光传输效率.结果表明:随着氟含量的升高,氟挥发现象愈加明显,传统大芯径掺氟包层光纤表面产生的裂纹、凹坑等缺陷增多,光纤损耗略有增加,激光传输效率下降;采用下陷掺氟内包层设计有效抑制了大芯径掺氟包层光纤制备过程中的氟挥发、析晶现象,1 200nm波段光纤损耗为3.99dB/km,平形和球形光纤2μm波段的激光传输效率分别达到88.9%和88.4%,性能明显高于传统结构光纤.