Te基远红外硫系玻璃光纤的制备及性能分析

随着光学技术由可见向中、远红外等长波长领域的发展,可透远红外的玻璃光纤研究成为近年来光学领域的发展热点之一.传统含Se的Te基硫系光纤无法工作于12μm以上的远红外.本文研究了新型GeTe-AgI硫系玻璃体系的提纯制备,利用挤压技术,制备了阶跃型GeTe-AgI远红外光纤,其光学损耗为:15.6 dB/m@10.6μm,整体低于24 dB/m@8—15μm.在实验过程中,首先采用传统的熔融-淬冷法和蒸馏纯化工艺制备了GeTe-AgI高纯玻璃样品.利用差示扫描量热仪、红外椭偏仪、红外光谱仪等测试了玻璃的物理性质和红外透过性能,分析了提纯工艺、AgI原料纯度对玻璃形成以及透过的影响,最后采用分步挤压法制备了芯包结构光纤.实验结果表明:蒸馏提纯和AgI原料纯度对玻璃的透过性能有着决定性的影响,同时Te含量的增加影响了玻璃的抗析晶能力,但新型挤压制备工艺和有效提纯技术共同保障了较低损耗Te基光纤的制备,所获得的GeTe-AgI光纤具有远红外宽谱应用的潜能(工作波段5.5—15μm)并且绿色环保,可以满足CO_2激光的能量传输和远红外传感应用.

Investigation on Te-based chalcogenide glasses for far-infrared fiber

When infrared (IR) is over 12 μm, conventional chalcogenide (ChG) fibers are confused by the multiphonon absorption of Se, and novel glass materials for far-IR have become one of hot research points in recent years. Here, a novel ChG glass and fiber for far-IR without containing Se/As is well investigated. The glasses GeTe-AgI are purified by distillation and synthesized by melt-quenching method. The thermal properties and the infrared transmissions are reported. The step-index fiber, fabricated via a novel extrusion method, exhibits excellent transmission at 8-15 μm:< 24 dB/m in a range of 8-15 μm and 15.6 dB/m at 10.6 μm. The influences of oxygen contaminant and the purity of AgI on the glass transmission and fiber attenuation are discussed. Structural and physical properties of GeTe-AgI glass system are studied with differential scanning calorimetry and ellipsometer instrument. Optical spectra of GeTe-AgI glass system are obtained by spectrophotometer and infrared spectrometer. Main purification process with oxygen-getters (magnesium) is disclosed. The fiber attenuation is measured by the cut-back method with a Fourier transform infrared spectrometer. The lowest loss of this fiber can be reduced to 15.6 dB/m at 10.6 μm. The results show that these glasses are well transparent in a wide IR window from 1.7 to 25 μm, and these glass fibers can transmit light up to 15 μm, thus the GeTe-AgI glass system is one of good candidates for far-IR. The fiber attenuation can be reduced effectively by the reasonable purification and novel extruded-processing. These environment friendly fibers are suited for far-IR applications, such as greenhouse gas sensing and the power delivery of CO₂ laser.