【作者】 刘爱云；

【导师】 赵修建；

【作者基本信息】 武汉理工大学 ， 材料学， 2003， 硕士

【摘要】 CO₂激光在激光医疗、激光加工等领域有着广泛的应用前景，但目前由于缺乏较好的传输材料而使其应用受到很大的限制，因此，研究与开发高性能传输CO₂激光的特种光纤已势在必行。本文着重设计制备Ag／COP（cyclicolefin polymer）泄漏型空芯光纤，并对其制备工艺进行了深入的研究。 通过对金属泄漏型空芯光纤与电介质／金属泄漏型空芯光纤传输特性的理论分析，选择制备电介质／金属泄漏型空芯光纤作为传输CO₂激光的材料。 实验用来制备空芯光纤的基管材料为石英基管；内径为1mm；通过理论推导与分析发现：相对于其它的金属材料而言，金属银的红外反射率最高，因此金属银最适合用做制备空芯光纤的金属膜层的材料；通过比较几种聚合物的性质确定选择环烯聚合物COP为电介质层材料；通过理论推导与计算确定了金属银膜与电介质膜的最佳理论厚度，即银膜为0.2μm，COP膜的厚度为1.4μm。 对银膜的制备工艺及影响银膜性能的因素如工艺条件、预处理过程、反应物浓度、反应时间等进行了研究，尤其对低浓度高温沉积银膜工艺与高浓度低温沉积银膜工艺的各影响因素进行了研究。通过实验比较研究了SnCl₂溶液的敏化效果及机理，对毛细管确定了较好的清洗工艺，确定了合适的实验参数，最终确定了合适的制备方案与工艺。 对COP膜的制备工艺及影响因素如COP溶液的浓度、提拉速度、热处理温度制度等进行了研究，确定了合适的COP膜制备工艺。 通过对制备的COP／Ag泄漏型空芯光纤和Ag空芯光纤的传输性能进行测试和分析发现，COP／Ag泄漏型空芯光纤的传输损耗比单纯Ag空芯光纤的损耗要低。单纯Ag空芯光纤的直传损耗最低为1.6dB／m，COP／Ag空芯光纤的直传损耗最低为1.45dB／m，即直传损耗降低了0.15dB／m。COP／Ag空芯光纤的弯曲损耗比Ag空芯光纤的弯曲损耗大大降低，尤其是随着弯曲角度的增加，降低的程度更明显。这与电介质／金属空芯波导的传输特性理论是一致的。同时，COP／Ag空芯光纤的传输稳定性也很好，能稳定传输55w的CO₂激光达35min以上。这表明所制备的COP／Ag空芯光纤能很好地用来传输CO₂医疗激光。更多还原

【Abstract】 The bright prospect of applications for COa laser in medical laser surgery, materials processing, etc, is presently darkened by the lack of efficient delivery tools. Whereas, there is an urgent need of manufacturing waveguides with excellent performances. This work focus on the design and fabrication of the Ag/COP(cyclic olefin polymer) leaky type of hollow waveguide.Dielectric/metal hollow waveguide theoretically exhibits a loss lower than that of the metal hollow fiber. Therefore the former is chosen in this research work.In the experiment silica glass tubes with diameters 1 mm were chosen as the basic fibers. Both the dielectric layer and metal film were internally deposited on the fiber. It is found that Ag is able to engender the highest IR reflectivity among the metal materials, So Ag is ascertained as the metal layer material of the hollow waveguide, COP was used in this work as the dielectric material. Based on countless calculations, optimum thickness for the deposited films were obtained, namely, 0.2 //m for Ag layer and 1.4 fan for the COP layer.In this work, the aspects those impose influences on the performances of the Ag films such as the pretreatment of the basic tubes, the concentrations of the reactants, the reaction time were investigated. Apart fffm this, great attention^ was given to the study on the parameters in the process of Ag deposition in which low concentration and high temperature, or high concentration and low temperature was alternatively adopted. The mechanism and the result of the sensitization via SnCb solution were profoundly investigated.On the base-of the careful study on the pretreatment process of the silica glass tubes, proper processing parameters were obtained. Reasonable process of depositing COP films was finally ascertained based on the investigations of the various factors such as the concentration of the coating solution, the withdraw used in the heat treatment of the COP film, and so on.It was confirmed that the loss of the COP/Ag leaky type of hollowwaveguide is lower than that of the simple Ag fiber. For example, in terms of the attenuation for straight delivery, the former is less than 1.45 dB/m while the latter is 1.6 dB/m. Accordingly, as far as the bent loss is concerned the Ag fiber is highly above the COP/Ag fiber, especially when the carve angle is increased. However, the above results follow the transmission laws of the dielectric/metal leaky type of hollow waveguide well. Moreover, it was found that the COP/Ag fiber can stably transmit COa laser for more than 35 minutes although the output laser reach as highly as 55 w. Therefore, the COP/Ag leaky type of hollow waveguide fabricated in this work will be a good candidate for COa laser delivery in medical surgery as well as material processing.更多还原