石英玻璃光纤金属涂层在线制备工艺

金属涂层光纤较传统有机涂层光纤具有高热稳定性、抗振动干扰等显著优势，但金属涂层光纤的连续在线制备技术在国内仍处于探索研发阶段，这也直接导致金属涂层光纤无法大批量连续生产，一定程度制约了我国高功率光纤激光器的飞速发展。提出并研制了一种基于熔融金属冷凝涂覆法的金属涂层光纤在线制备装置，经与光纤拉丝塔耦合，能够实现边拉丝边涂覆金属，并且涂层厚度可控。基于该工艺成功拉制了涂层均匀、涂层表面质量良好、直径稳定的铝涂层光纤。通过实验和模拟计算，探讨了影响光纤金属涂覆层质量的影响因素，主要包括了光纤入口温度、液铝温度、模具孔径、接触距离等。通过研究，确定了最佳铝液温度为663~690 ℃，且发现涂覆厚度与铝液温度的线性递减关系；计算了拉丝速度与冷却距离的关系；给出了陶瓷上下模具螺丝的孔径大小、光纤与液态铝接触深度的最佳值。研究成果为金属涂覆光纤的批量生产问题提供了解决方案，为打破国际技术垄断奠定了基础。

Online preparation technology of quartz glass fiber with metal coating

Compared with the traditional organic-coated fiber, the metal-coated fiber has significant advantages such as high thermal stability and anti-vibration interference. However, the continuous online preparation technology of metal-coated fiber is still in the research and development stage in China, which directly leads to the failure of large-scale continuous production of metal-coated fiber, and to a certain extent, limits the rapid development of high-power fiber lasers in China. An on-line fabrication device of metal-coated fiber based on molten metal condensation coating method was proposed and developed. Coupling with the fiber drawing tower, it can realize metal coating while drawing, and the coating thickness can be controlled. Aluminum coated fiber with uniform coating, good surface quality and stable diameter had been successfully fabricated. The influences of fiber inlet temperature, liquid aluminum temperature, mold aperture and contact distance on the coating quality of metal coating were discussed. By theoretical analysis and practical experiment, the optimum temperature of aluminum liquid is 663-690 ℃, and the linear decreasing relationship between the thickness of coating and the temperature of aluminum liquid was obtained. The relationship between drawing speed and cooling distance was calculated. The optimal aperture size of screw of ceramic upper and lower die and the contact depth between optical fiber and liquid aluminum were given. The research results provide a solution to the problem of mass production of metal-coated fiber and lay a foundation for breaking the international technology monopoly.