Synthesis, Characterization, and Modeling of Rare Earth Ions in Polycrystalline Ceramic and Polymeric Plastic Hosts

技术：该项目旨在更好地了解固态激光器的发展。期望的特性包括更高的功率输出、更高的波束质量和更宽的频率覆盖。该项目将探索多晶陶瓷YAG激光主机，与传统的单晶激光材料相比，它可能具有更好的光学、热学和物理性能，并且成本更低。发光聚合物也将被考虑用于发光二极管和有机基激光器。稀土（RE）掺杂塑料激光宿主材料的一个主要优点是，它们可以被制成柔性光纤，用于光子应用。在这项工作中，将研究六种新的稀土离子掺杂-宿主组合在多晶石榴石和聚合物塑料宿主中的作用。材料将包括三价稀土（Pr， Tm和Yb）离子，这些离子将分别掺杂在多晶陶瓷基体Y3Al5O12 （YAG）和聚合物塑料基体中。所有材料都将使用温度依赖吸收光谱，稳态和时间分辨荧光研究以及激光性能研究进行表征。Judd-Ofelt理论将用于确定相关的光谱和激光参数。此外，将对这些宿主环境中的稀土离子进行配体和晶体场的建模，以获得它们的能级结构。将利用自由离子或原子参数和晶体场分裂参数的模型哈密顿量来分析这些离子的详细能级结构，并与测量结果进行比较。该研究有望为激光参数与吸收、发射、激发、发射截面、量子效率、RE离子之间的能量转移、荧光猝灭、斯托克位移以及直接环境（宿主）对这些过程的影响等物理基础提供重要的联系。非技术：该项目涉及具有技术相关性的材料科学主题领域的基础研究问题。该研究将在基础层面上为材料科学知识提供新的理解和电子/光子器件的能力。该计划的一个重要特点是通过培养学生在一个基础和技术上重要的领域的研究和教育的整合。该项目的多学科性质旨在提高南南大学的教育质量。UTSA坚定地致力于培训所有学生，其中包括来自圣安东尼奥和南德克萨斯地区的少数族裔学生，他们拥有高级科学学位。通过积极招聘和留用，努力提高学生对研究的参与。由于在UTSA有大量的西班牙裔学生（55%），拟议的研究项目将吸引大量代表性不足的学生。

Technical: This project aims for greater understanding useful for development of solid-state lasers. Among desired properties are higher power output, higher beam quality, and wider frequency coverage. The project will explore polycrystalline ceramic YAG laser host which may have improved optical, thermal, and physical properties as well as lower cost over traditional single-crystal laser materials. Luminescent polymers will also be considered for light emitting diode and organic based laser applications. A major advantage of rare earth (RE)-doped plastic laser host materials is that they could be drawn into flexible, optical fibers for photonic applications. In this work, six novel dopant-host combinations of RE ions in polycrystalline garnet and polymeric plastic hosts will be studied. Materials will include trivalent RE (Pr, Tm, and Yb) ions that will be individually doped in the polycrystalline ceramic host, Y3Al5O12 (YAG) and a polymeric plastic host. All materials will be characterized using temperature dependent absorption spectroscopy, steady-state and time-resolved fluorescence studies, and laser performance studies. The Judd-Ofelt theory will be used to determine relevant spectroscopic and laser parameters. In addition, modeling of the ligand and crystal field will be performed for the RE ions in these host environments to obtain their energy-level structures. A model Hamiltonian in terms of free-ion or atomic parameters and crystal-field splitting parameters will be utilized to analyze the detailed energy-level structure of these ions which will be compared with measurements. The research is expected to provide an important link between laser parameters and physics fundamentals associated with absorption, emission, excitation, emission cross-section, quantum efficiency, energy transfer between RE ions, fluorescence quenching, Stoke's shift, and the effect of the immediate environment (host) on such processes.Non-Technical: The project addresses basic research issues in a topical area of materials science having technological relevance. The research will contribute materials science knowledge at a fundamental level to new understanding and capabilities in electronic/photonic devices. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The multidisciplinary nature of this project is aimed to enhance the quality of education at UTSA. UTSA has a strong commitment to train all students, which includes underrepresented minority students from San Antonio and the South Texas region with advanced degrees in science. Efforts will be made to enhance students' participation in research through active recruitment and retention. Because of the large Hispanic student population (55%) at UTSA, the proposed research program will attract a significantly large number of underrepresented students.