中红外稀土掺杂氟碲酸盐玻璃光纤的制备及发光机理研究

Mid-infrared(3-5μm) fibers have been expected to be used in the civil and military areas. However, strict requirements are demanded as material of mid-infrared fiber. So far, mid-infrared laser output has been achieved only in fluoride fiber. Despite their advantages, undesirable physical and chemical properties of fluoride glass fibers limit their applications as high-power laser gain medium. This project aims to explore a new kind of mid-infrared fiber, rare-earth-doped fluoride tellurite glass fiber. Then the relationship and luminescence mechanism between the infrared luminescence properties of rare earth ions, the composition of fluoride tellurite glass, doping concentration, and other parameters will be investigated. By adjusting the content of raw materials and conbining the experimental and theoretical simulation of material performance, the relationship between the composition, structure and properties is analyzed and optimal fluoride tellurite glass could be obtained with low phonon energy, excellent crystallization stability and high laser damage threshold. In addition, the design and preparation of rare earth doped fluoride tellurite glass fiber is explored to obtain its high-strength and low-loss properties. Moreover, the effects of different factors such as the fiber length, doping concentration, the structure of fiber end face, and the pump wavelength on the mid-infrared luminescent characteristics of the fiber are systematically investigated to achieve laser output. It is believed that the study of this project can promote the design and development of new mid-infrared glass fiber materials and related devices.

中红外波段(3-5μm)光纤在民用和军事上有广阔应用前景，但是中红外光纤对材料要求苛刻，难于制备，国际上仅在氟化物光纤中实现中红外波段激光输出。而氟化物玻璃光纤物化性能差，限制了其作为高功率激光器增益介质的应用。本项目拟开展新型中红外稀土掺杂氟碲酸盐玻璃光纤的研究，旨在掌握稀土离子中红外发光特性与氟碲酸盐玻璃组成、掺杂浓度等参数之间的变化规律及发光机理。通过对玻璃基质组分的调整，实验和理论模拟相结合，解析材料组成-结构-性能之间的关系，进一步降低氟碲酸盐玻璃的声子能量，提高析晶稳定性和抗激光损伤阈值。掌握掺稀土氟碲酸盐玻璃光纤预制棒设计和光纤制备工艺，降低光纤的损耗并提高其强度。探明光纤长度、掺杂浓度、光纤端面结构、泵浦波长与稀土离子在光纤中的中红外发光特性之间的变化规律，最终获得激光输出。通过本项目的研究为今后在理论上设计和开发新型中红外玻璃光纤材料及相关器件提供科学的基础技术支持。

中红外波段光纤在民用和军事上有广阔应用前景，但是中红外光纤对材料要求苛刻，难于制备，国际上仅在氟化物光纤中实现中红外波段激光输出。而氟化物玻璃光纤物化性能差，限制了其作为高功率激光器增益介质的应用。本项目以探索实现新型中红外波段稀土掺杂发光氟碲酸盐玻璃为研究目标，解决中红外波段光纤激光器用增益材料稀土掺杂玻璃光纤所涉及的基础问题为研究内容。通过对氟碲酸盐玻璃组分、玻璃熔制工艺的设计和优化，制备得到了兼有机械强度高、热稳定性能好、化学稳定性能和析晶稳定性能优良、低声子能量的高光学质量掺稀土氟碲酸盐玻璃组份；通过改变稀土离子浓度、敏化离子组合方式、泵浦波长等因素，研究其对稀土掺杂氟碲酸盐玻璃中红外波段发光效率和发光性能参数的影响规律，提高发光效率，优化发光性能参数。通过改进光纤拉丝工艺实现掺稀土氟碲酸盐玻璃光纤的拉制，并进行光纤的荧光及激光特性测试，获得高强度的掺稀土氟碲酸盐玻璃光纤。本课题研究的掺稀土氟碲酸盐玻璃光纤材料，可为研制具有自主知识产权的稀土掺杂特种光纤，发展中红外波段光纤激光器提供科学依据和技术储备。