Metasurface-based Ultrafast Optical Metrology

超快激光器具有广泛的应用，从实现高精度材料加工和高速通信网络到推进医疗程序和捕获超快事件。超表面是微小光学结构的阵列，可以以非凡的方式操纵光，提供紧凑轻便的光学元件，并使便携式电子产品取得进步。尽管超表面已广泛用于光学元件和器件，但还没有尝试将超表面用于超快激光脉冲表征。该项目旨在开发基于超表面的小型化超快脉冲表征设备，使超快激光源得到更广泛的应用。参与本研究的研究生和本科生将接受各研究学科的综合训练。通过积极让女性和少数民族学生参与研究项目，将促进多样性和包容性。作为这一举措的一部分，首席研究员致力于组织开放的房子活动，以展示研究前大学的学生。拟议研究的科学发现将通过常规科学渠道、社区外展和媒体渠道广泛传播。该项目将开发紧凑的基于超表面的设备，能够准确表征超快光脉冲的时间和空间特性。这些器件需要线性和非线性超表面的结合。超快光学测量要求器件的非线性响应同时表现出高效率、宽带宽和高方向性。这种需求组合对元表面设计提出了重大挑战。该项目将为克服这些挑战和推进超快计量领域提供系统的解决方案。该项目包括三个重点：1)开发具有高非线性效率、方向性和宽带宽的非线性多极介质超表面；2)开发紧凑、精确的基于超表面的自相关器和频率分辨光门控装置，用于超快光脉冲的时间表征；3)开发基于超表面的剪切干涉仪，用于表征超快光脉冲的空间波前。所设计的器件有望具有优异的信噪比。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Ultrafast lasers have a wide range of applications, from enabling high-precision material processing and high-speed communication networks to advancing medical procedures and capturing ultrafast events. Metasurfaces are arrays of tiny optical structures that can manipulate light in remarkable ways, offering compact and lightweight optical components and enabling advancements in portable electronics. Despite that metasurfaces have been used for a wide range of optical elements and devices, there has been no attempt to utilize metasurfaces in ultrafast laser pulse characterization. This project aims to develop miniaturized metasurface-based ultrafast pulse characterization devices, enabling a broader adoption of ultrafast laser sources. The graduate and undergraduate students participating in this research will receive comprehensive training across various research disciplines. The diversity and inclusion will be promoted by actively involving female and minority students in the research projects. As part of this initiative, the Principal Investigator is committed to organizing open house events to showcase the research to pre-college students. The scientific findings of the proposed research will be broadly disseminated through regular scientific channels, community outreach, and media outlets. This project will develop compact metasurface-based devices capable of accurately characterizing both the temporal and spatial properties of the ultrafast optical pulses. These devices require a combination of linear and nonlinear metasurfaces. The ultrafast optical metrology requires nonlinear response of the components to demonstrate simultaneously high efficiency, wide bandwidth, and high directionality. This combination of requirements poses significant challenge for metasurface design. This project will provide a systematic solution to overcome these challenges and advance the field of ultrafast metrology. The project consists of three thrusts: 1) developing a nonlinear multipolar dielectric metasurface with high nonlinear efficiency, directionality, and broad bandwidth, 2) developing compact and accurate metasurface-based autocorrelator and frequency-resolved optical gating devices for temporal characterization of ultrafast optical pulses, and 3) developing a metasurface-based shearing interferometer for characterizing the spatial wavefront of ultrafast optical pulses. The designed devices are expected to have excellent signal-to-noise ratios.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.