RII Track-4:NSF: Investigation of Stress Induced Birefringence and Refractive Index Changes in Glass for Fabricating Novel Optics

RII Track-4：NSF：用于制造新型光学器件的玻璃中应力引起的双折射和折射率变化的研究

• 批准号: 2327218
• 负责人: Heng Zuo
• 金额: $ 29.98万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2327218&HistoricalAwards=false
• 关键词: RII; Track; NSF; Investigation; Stress

The capability of the ultrafast laser micromachining technique to reliably alter material properties and create sub-micron-scale features in materials, such as glass, with high throughput, high precision, and low cost, can be harnessed to facilitate the fabrication of various optics, including waveguides, waveplates, volume gratings, and quantum optics. Additionally, it enables the production of optical components that can be used in astronomy mirrors, space communication, and virtual reality devices. Many applications of the ultrafast laser micromachining technique depend on achieving a reliable change in refractive index and/or birefringence, as well as introducing controlled stress states to the substrates. However, since laser irradiation can trigger both the accumulation of stress and modification of refractive index, the relationship between them has not been well explored, and the underlying mechanism leading to different levels of birefringence is not fully understood, which limits the application of such techniques in various materials. In this project, we plan to address this knowledge gap by conducting an extensive parameter study to investigate stress-induced birefringence and refractive index changes in thin glass substrates subjected to different ultrafast laser processing conditions. The knowledge obtained from this project will contribute to improving the quality of laser-written optical components and enhancing the efficiency of diffractive elements.This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows project will provide a fellowship to an Assistant professor and training for a graduate student at the University of New Mexico. This project proposes collaboration with Dr. Brandon Chalifoux at the University of Arizona (UA), who will provide access to a state-of-the-art femtosecond laser material processing system (Trumpf TruMicro 2030) as well as several key metrology tools. The project team will utilize this laser to write over a well-defined region on the glass substrate, measure birefringence, stress, and refractive index changes, and investigate various laser irradiation and focusing parameters, including pulse energy, pulse duration, pulse density, polarization, beam shaping, and numerical aperture. The three specific objectives to be pursued in this project are: (1) developing the procedure for measuring birefringence and refractive index change using an optical microscope equipped with differential interference contrast, phase imaging, and a polarization camera; (2) establishing a parameter space to create different levels of birefringence and refractive index changes in fused silica and N-BK7 glass using a combination of ultrafast laser processing parameters; and (3) developing a finite element model to simulate the stress field and local electric field in the laser-processed regions and comparing it with experimental measurements. This fellowship will have a transformative impact on the trajectory of the research career of the PI, Dr. Heng Zuo, an early-career faculty member in Mechanical Engineering at the University of New Mexico, a minority-serving institutionI and Hispanic-Serving Institution. It will also advance laser manufacturing education for undergraduate and graduate students at UNM, providing hands-on research training opportunities and broadening research participation among underrepresented groups, thereby strengthening UNM's competitiveness in the field of advanced manufacturing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

超快激光微加工技术可靠地改变材料特性并在材料中创建亚微米尺度特征，例如玻璃，具有高吞吐量，高精度和低成本的材料，可以利用以促进各种光学器件的制造，包括波导，波导，波动板，体积，体积，量符和量子光学。此外，它可以生产可用于天文镜，空间通信和虚拟现实设备的光学组件。超快激光微加工技术的许多应用取决于实现折射率和/或双发性折射率的可靠变化，以及向基板引入受控应力状态。但是，由于激光照射可以触发压力的积累和折射率的修饰，因此尚未充分探索它们之间的关系，并且导致不同水平的双折射的基本机制尚不完全了解，这限制了此类技术在各种材料中的应用。在该项目中，我们计划通过进行广泛的参数研究来解决这一知识差距，以研究应激诱导的双重双重玻璃基板的双重双重和折射率变化。从该项目获得的知识将有助于提高激光写入的光学组件的质量并提高衍射元素的效率。本研究基础设施改进Track-4 Epscor Research Fellows项目将为新墨西哥大学的一名研究生助理教授和培训提供奖学金。该项目提议与亚利桑那大学（UA）的布兰登·查尔福克斯（Brandon Chalifoux）博士合作，后者将访问最先进的激光材料处理系统（Trumpf Trumicro 2030）以及几种关键的计量工具。项目团队将利用该激光器在玻璃基板上的一个定义明确的区域上写入，测量双重性，压力和折射率变化，并研究各种激光辐照和聚焦参数，包括脉冲能量，脉冲持续时间，脉冲持续时间，脉冲持续时间，脉冲密度，极化，光束，束形和数字射击。该项目中要追求的三个特定目标是：（1）使用配备有差异干扰对比度，相像成像和极化摄像头的光学显微镜制定了测量双折射和折射率变化的程序； （2）建立一个参数空间，以使用超快激光处理参数的组合在熔融二氧化硅和N-BK7玻璃中创建不同水平的双折射和折射率变化； （3）开发一个有限元模型，以模拟激光处理区域中的应力场和局部电场，并将其与实验测量进行比较。该奖学金将对PI研究生涯的轨迹产生变革性的影响，新墨西哥大学的机械工程早期教师Heng Zuo博士，少数派服务机构和西班牙裔服务机构。它还将推动UNM的本科生和研究生的激光制造教育，提供动手的研究培训机会并扩大人为不足的群体的研究参与，从而增强了UNM在高级制造领域的竞争力。这项奖项反映了NSF的立法任务，并通过对基金会的智力进行了评估，并以评估的评估值得评估。