Nonradiative and Radiative Processes of Doped Nanocrystallites in Porous Glasses

0417807 ALFANO该项目的目标是启动激光活性Cr 4+掺杂纳米微晶嵌入多孔玻璃介质的宽光谱带激光和光学放大应用（1100 nm至1600 nm）的发展。这些材料联合收割机结合了Cr 4+掺杂晶体的良好辐射性能和玻璃的优点。拟议的研究将集中在克服这些问题的材料，并联合收割机结合良好的辐射性能的Cr 4+掺杂晶体和玻璃的优点。这种类型的介质可以被认为是单晶和玻璃之间的中间体。由于尺寸效应和纳米晶体与周围基质的良好隔离，掺杂纳米晶体的光学性质预计与体材料的性质非常不同。掺杂纳米晶体和玻璃基质之间的相互作用将提供信息，以更好地理解固体中的非辐射猝灭机制。 为了研究嵌入纳米尺寸晶体的多孔玻璃中的光学性质和能量传递机制，将进行一组光谱和时间分辨的拉曼测量。用SNOM和扫描共聚焦显微镜进行的空间分辨测量将揭示纳米晶体的局部光学性质。测量将在生长到玻璃基质的孔中的不同化学组成的掺杂纳米晶体上进行。样本将在纽约城市学院内部制备。 拟议的研究可能会导致更有效的光子学材料的设计，并有可能彻底改变宽带光通信和光放大器和激光器的光器件技术。 该项目将整合研究和教育活动，以扩大技术进步和技术人员培训的机会。 一些研究生和本科生将接受溶胶-凝胶材料制备，光谱测量和激光技术的培训，一些高中生（11-12年级）也将参与激光开发研究。

0417807ALFANOThe objective of this project is to initiate the development of laser Active Cr4+-doped nano-crystallites embedded in porous glass media for wide spectral band laser and optical amplification applications (1100 nm to 1600 nm). These materials combine favorable radiative properties of Cr4+-doped crystals and the advantages of glasses. The proposed research will be focus on materials that overcome these problems and combine favorable radiative properties of Cr4+ doped crystals and the advantages of glasses. Media of such type can be considered an intermediate between single crystals and glasses. The optical properties of doped nanocrystals are expected to be very different than the properties of bulk materials, due to size effects and good isolation of the nanocrystals from the surrounding matrix. The interaction between the doped nanocrystals and the glass matrix will provide information to better understand the nonradiative quenching mechanism in solids. To study the optical properties and energy transfer mechanisms in the porous glass with embedded nanosize crystals, a set of spectroscopic and time-resolved Raman measurements will be performed. Spatial resolved measurements with SNOM and Scanning Confocal microscopy will reveal optical properties locally at the nanocrystals. The measurements will be carried out on doped nanocrystals of different chemical compositions grown into pores of the glass matrix. Samples will be prepared in house at the City College of New York. The proposed research may lead to the design of more efficient Photonics materials and has the potential to revolutionize wide band optical communications and optical device technology for optical amplifiers and lasers. The project will integrate research and educational activities to Extend opportunity for advancing the technology and training of skilled personnel. Several graduate and undergraduate students will be trained in sol-gel material preparation, spectroscopic measurements and laser technology, several high school students (grades 11-12) will also become involved in laser development research.