Metasurface-based Ultrafast Optical Metrology

超快激光有着广泛的应用，从实现高精度的材料处理和高速通信网络，到推进医疗程序和捕捉超快事件。超表面是微小光学结构的阵列，可以以非凡的方式操纵光线，提供紧凑和轻便的光学组件，并使便携式电子产品取得进步。尽管亚表面已经被广泛地用于光学元件和器件，但还没有尝试将亚表面用于超快激光脉冲的表征。该项目旨在开发基于超表面的小型化超快脉冲表征设备，使超快激光光源能够得到更广泛的采用。参与这项研究的研究生和本科生将接受跨不同研究学科的综合培训。通过积极让女性和少数族裔学生参与研究项目，将促进多样性和包容性。作为这项倡议的一部分，首席调查员致力于组织开放参观活动，向大学预科学生展示这项研究。拟议研究的科学成果将通过常规科学渠道、社区宣传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，能够准确地描述超快光脉冲的时间和空间特性。这些设备需要线性和非线性变形曲面的组合。超快光学测量需要器件的非线性响应，以同时表现出高效率、宽带宽和高方向性。这种需求的组合给变形表面设计带来了巨大的挑战。该项目将为克服这些挑战提供一个系统的解决方案，并推动超快计量领域的发展。该项目包括三个方面的工作：1)研制具有高非线性效率、高方向性、高带宽的非线性多极介质亚表面；2)开发紧凑而精确的亚表面自相关器和频率分辨光学选通装置，用于超快光脉冲的时间特性；3)研制用于表征超快光脉冲空间波前特性的亚表面剪切干涉仪。设计的设备预计将具有出色的信噪比。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.