Collaborative Research: Designing Glass Structures for Femtosecond Laser Processing

非技术描述：脉冲短于万亿分之一秒的超快激光可用于在玻璃片内创建微米大小的结构。这种制造方法为制造光子器件和电路提供了平台， 光通信、生物成像和传感以及纳米技术。为了充分利用这种超快激光“写入”技术的潜力，设计在器件特性和激光加工行为方面都进行优化的材料是很重要的。为了实现这一目标，该项目旨在开发此类材料，并详细了解激光如何在微观尺度上改变材料结构。该研究是加州大学戴维斯分校和密苏里州ST之间的合作，并为研究生，本科生和大学预科学生提供最先进的材料科学和光学技术，本科生和大学预科水平的外展活动的研究机会的培训。技术规格：飞秒激光在玻璃基片上写入光波导是一种很有前途的集成光子器件制作技术。器件的质量取决于玻璃对飞秒激光加工条件的响应以及玻璃成分。磷酸盐玻璃作为有源器件的主体材料是令人感兴趣的，因为它们允许掺入高浓度的稀土离子，通常在激光曝光区域产生负折射率变化，导致光学性能差。然而，某些组合物表现出器件制造所需的正折射率变化。该项目的总体目标是对磷酸盐玻璃对飞秒激光照射的响应的材料参数有一个基本的了解。进行实验以确定玻璃结构和响应于fs激光处理之间的关系，并使用荧光、拉曼、微核磁共振和ESR技术等来表征fs激光诱导的玻璃结构变化。实验结果被用来开发一个模型，描述相关的玻璃结构参数的飞秒激光响应，并最终设计新的玻璃组合物。该项目是具有光学材料和激光物理（加州大学戴维斯分校）和玻璃化学（密苏里州ST）专业知识的团体之间的合作，并为研究生提供最先进的材料科学和光学技术的培训，为本科生提供研究机会，并在大学预科水平开展外联活动。

NON-TECHNICAL DESCRIPTION: Ultrafast lasers with pulses shorter than a trillionth of a second can be used to create micron-sized structures inside a piece of glass. This fabrication method provides a platform for the fabrication of photonic devices and circuits with applications in optical communications, bio-imaging and -sensing and nanotechnology. In order to exploit the full potential of this ultrafast laser 'writing' technique it is important to design materials that are optimized both in terms of device properties and laser processing behavior. Towards this goal this project aims to develop such materials as well as a detailed understanding of how the laser changes the materials structure on a microscopic scale. The research is a collaboration between UC Davis and Missouri S&T and provides training for graduate, undergraduate and pre-college students in state-of-the-art materials science and optical techniques, research opportunities for undergraduates and outreach activities at the pre-college level. TECHNICAL DETAILS: Femtosecond (fs)-laser writing of optical waveguides inside glass substrates is a promising technique for fabricating integrated photonic devices. The quality of the device is determined by the response of the glass to fs laser processing conditions as well as glass composition. Phosphate glasses, which are of interest as host materials for active devices since they allow incorporation of high concentrations of rare earth ions, typically produce negative refractive index changes in the laser-exposed regions, leading to poor optical performance. However, certain compositions exhibit positive refractive index changes that are desirable for device fabrication. The overall objective of the project is to develop a fundamental understanding of the materials parameters that govern the response of phosphate glass to femtosecond laser irradiation. Experiments are conducted to determine the relationships between glass structure and response to fs-laser processing and to characterize fs-laser induced changes in glass structure using fluorescence, Raman, micro-NMR and ESR techniques, among others. The experimental results are used to develop a model that describes the fs-laser response in terms of relevant glass structural parameters and ultimately design new glass compositions. This project is a collaboration between groups with expertise in optical materials and laser physics (UC-Davis) and glass chemistry (Missouri S&T) and provides training for graduate students in state-of-the-art materials science and optical techniques, research opportunities for undergraduates and outreach activities at the pre-college level.