单分散晶相复合稀土掺杂硫系玻璃陶瓷的可控制备与随机激光特性研究

Mid-IR laser in 3-5 μm wavelength range has a lot of significant applications for the civil use and national defense. There already have multiple ways toward the laser sources within this wavelength range, but the selection is limited. So the development of mid-IR laser materials is one of the hottest topics in the photonics field. Chalcogenide glass (ChG) is a kind of non-crystalline matrix that is promising for mid-IR laser in solid-state or fiber form. However, it also faces several problems hard to be resolved, such as low solubility of rare earth ions for the ChG composition with good fiber processing property but ChG with high REI solubility easy to be crystallized during the fiber drawing, as well as weak mechanical or physiochemical properties. To avoid the above-mentioned deadlock of the development of ChG-based mid-IR laser, therefore, the concept of random laser is introduced in this project. We propose a comprehensive study on the controllable crystallization mechanism through the micro- or nano- phase separation of ChG and the regulation mechanism of random laser in ChG-ceramics, to grasp the method of controlling the monodisperse microstructure of ChG-ceramics by compositional elaboration, and finally to obtain the ChG-ceramics with high optical gain and strong scattering property. And then, combined with the investigation of the random lasering property of ChG powder, we will conduct the studies of the generation conditions of random lasering in monodisperse microstructured ChG-ceramics through altering the parameters of doping ways, particle size, crystal phase, and distribution, to achieve the output of random laser and to learn a series of the key parameters of the generation of mid-IR random laser. The implementation of this project would build solid foundations of new materials and theoretical basis for the further development of superior mid-IR random laser with solid-state or even fiber form.

3-5μm中红外激光在民用和军用领域有着十分重要的应用价值，相关中红外激光材料研发一直是光子学领域的热门主题之一。硫系玻璃是一类极具希望实现中红外激光输出的非晶态基质材料，但是也存在不足之处（如稀土溶解度高的玻璃组分易析晶，而成玻能力好可拉制光纤的玻璃组分稀土溶解度低的矛盾），使目前以其为基质的稀土掺杂中红外激光器研发工作进展极为缓慢。因此，本项目将基于随机激光原理避开上述难点，拟通过硫系玻璃微纳分相控制晶化机理和稀土掺杂玻璃陶瓷随机激光调控等问题的深入研究，掌握硫系玻璃陶瓷单分散显微结构可控制备方法，通过掺杂方式、晶粒尺寸、分布、晶相类型等材料特性以及泵浦激光等参数的选择与优化，获得高增益强散射玻璃陶瓷材料，与此同时结合硫系粉末随机激光特性，揭示基于单分散晶相复合稀土掺杂硫系玻璃陶瓷的随机激光调控机制，最终实现中红外随机激光的输出，为今后新型中红外激光器的设计与实现奠定新材料和理论基础。

红外硫系玻璃是目前唯一能在3-5μm中波红外和8-14μm长波红外透明的非晶态材料，独占了其它光学玻璃无法进入的红外热成像、红外传感和遥感等中远红外应用领域。硫系玻璃具有较小的折射率温度系数(dn/dT约为锗单晶的八分之一)、组分可调、可精密模压、超高超快响应的非线性光学性质、易掺杂、可成纤成膜等优势，更是单晶硅、单晶锗、硒化锌和硫化锌等红外晶体材料难以匹敌。基于硫系玻璃的红外光子器件成为近年来国际光子学领域的研究热点之一。发展新型高品质红外硫系玻璃材料是其中关键所在。本项目细致研究了硫系玻璃组分、结构、分相与析晶行为之间的关联规律，单分散晶相复合硫系玻璃陶瓷制备及性能，以及单分散晶相复合稀土掺杂硫系玻璃陶瓷的发光特性等三方面内容。由此，掌握了通过玻璃组分调控自组织微纳尺度分相结构的方法，阐明了硫系玻璃析晶过程中纳米多晶或单晶显微结构的形成机理（取决于构成玻璃网络框架的基本结构单元是否参与晶化过程），提出了硫系玻璃熔体法金属卤化物纳米晶的可控析晶方法，制备出了CsX、PbX2、CsPbX3、CsSnX3（X=Cl、Br、I）等纳米晶复合的硫系玻璃陶瓷材料，揭示出Ostwald熟化控制的卤化物析晶行为，与此同时分析了中红外随机激光产生的条件，为后续研究指明了方向。