SGER: Quantum Electronic Properties of Ultraviolet Laser Phosphors

9975542 RandThis项目调查从根本上新的，量子光学性质的强散射粉末的氧化物纳米晶体掺杂稀土离子。 在强多重散射区，用1-10 keV能量范围内的电子激发产生无辐射激光发射。 含有紫外线发射离子的氧化铝纳米晶体的粉末通过火焰喷射醇盐前体来合成，该方法导致优异的颗粒均匀性、可控的尺寸和高纯度。 使用可溶性金属有机前体以超过250 g/h的速率产生具有与溶液组成相同的组成和5-100 nm范围内的平均粒径的未附聚粉末。 这些材料的发射性能，然后检查阴极射线发光在真空中。 一个重要的目标是探索的基本机制，负责在介质中的光学增益如此高度衰减，电磁辐射经历“经常性”的散射事件，并强烈本地化。 因此，在新兴的跨学科领域提供了研究生和博士后学生的优秀培训。 合适的过渡和实验条件正在研究高效，连续产生的紫外和可见光受激发射的纳米荧光粉，利用相干光学技术探测其散射特性。紫外激光荧光粉与其他受激发射光源不同，它能产生无散斑的非相干光。该项目研究了在非常小的氧化物单晶的强散射粉末中遇到的全新的量子光学过程。 从纳米粉末中产生连续的紫外和可见激光发射的电生成预计将导致在可适形光源、显示器、光刻和改进的磷光体中的许多应用。 这种跨学科的研究为研究生和博士后研究人员提供了一个具有挑战性的培训基地，在新兴技术领域结合了最先进的化学，电子光谱学和相干光学测量。

9975542RandThis project investigates fundamentally new, quantum optical properties of strongly scattering powders of oxide nanocrystals doped with rare earth ions. Mirrorless laser emission is produced by excitation with electrons in the energy range 1-10 keV in the strong, multiple-scattering regime. Powders of alumina nanocrystals containing ultraviolet-emitting ions are synthesized by spraying alkoxide precursors through a flame, in a process that results in excellent particle uniformity, controllable size, and high purity. The use of soluble metallorganic precursors yields unagglomerated powders with compositions identical to the solution compositions and average particle diameters in the 5-100 nm range, at rates of over 250 g/h. The emissive properties of these materials are then examined by cathodoluminescence in ultrahigh vacuum. An important objective is to explore the fundamental mechanisms responsible for optical gain in media so highly attenuating that electromagnetic radiation undergoes "recurrent" scattering events and is strongly localized. Excellent training of graduate and postdoctoral students in an emerging cross-disciplinary field is thereby provided. Suitable transitions and experimental conditions are being studied for efficient, continuous generation of ultraviolet and visible stimulated emission in nanophosphors, utilizing coherent optical techniques to probe their scattering properties. Ultraviolet laser phosphors are expected to be quite unlike other stimulated emission sources by generating speckle-free, incoherent light.%%%This project investigates fundamentally new, quantum optical processes encountered in strongly scattering powders of very small, oxide single crystals. Electrical generation of continuous, ultraviolet and visible laser emission from nanopowders is expected to lead to numerous applications in conformable light sources, displays, lithography and improved phosphors. This inter-disciplinary research provides a challenging training ground for graduate students and postdoctoral research associates in an emerging technology area combining state-of-the-art chemistry, electron spectroscopy, and coherent optical measurements.***