溶胶-凝胶法制备Al3+、Yb3+掺杂石英光纤纤芯的研究

以正硅酸乙酯、氯化铝和氯化镱为前驱体, 用溶胶-凝胶法制备了Al³⁺、Yb³⁺掺杂石英光纤纤芯。采用ICP-AES分析发现: 碱催化的掺杂硅凝胶上下层组分存在较大差异, 酸催化条件能够消除组分差异。将酸催化溶胶经凝胶化、热处理、玻璃化、光学加工, 获得了φ2.5 mm×50 mm的芯棒。测试2 mm厚芯棒玻璃的光谱和荧光寿命, 1020 nm的荧光寿命为896 μs, 羟基含量为0.4×10^-6, 并通过显微拉曼光谱分析玻璃结构。采用管棒法制备预制棒, 2000℃高温拉制了Al³⁺、Yb³⁺掺杂单包层石英光纤。用光纤折射率分布测试仪测得纤芯折射率波动Δn小于2×10^-4, 表明纤芯具有良好的光学均匀性。本研究结果提供了一种大模场掺镱石英光纤纤芯材料的制备方法, 并为溶胶-凝胶法制备均匀多组分材料的研究提供了理论参考。

Sol-Gel Derived Al3+,Yb3+ Co-doped Silica Fiber Core

Using TEOS, YbCl₃, AlCl₃ as precursors, Al³⁺, Yb³⁺ co-doped silica fiber core glass was fabricated by Sol-Gel method. ICP-AES tests showed that the compositions of the gel derived from base catalyzed sol were not uniform. The composition inhomogeneity of the gel was eliminated by acid catalyzed sol. The Al³⁺, Yb³⁺ co-doped silica core glass with 2.5 mm in diameter and 50 mm in length was obtained after heat-treatment, melting and polishing. The absorption, infrared transmission and fluorescence spectra were measured with glass slice at 2 mm thickness. The fluorescent lifetime centered at 1020 nm was 896 μs, and the Hydroxyl radical (-OH) content was 0.4×10^-6. The glass structures from acid and base catalyzed sols were analyzed by micro Raman spectroscope. Fiber preform was fabricated by rod-in-tube technique with the obtained core glass. The Al³⁺, Yb³⁺ co-doped single cladding silica fiber was drawn at 2000℃. Its optical homogeneity was evaluated by the refractive index profiler. Refractive index difference (Δn) in fiber core area was less than 2×10^-4. This work can supply homogeneous and large size core glass for large mode PCF and large mode cladding fiber. And it can provide reference for preparation of homogeneous multi-component optical material by the Sol-Gel method.