CAREER: Flat Singular Optics: Generation and Detection of Optical Vortex Beams with Plasmonic Metasurfaces in Linear and Nonlinear Regimes

摘要：职业：平面奇异光学：线性和非线性条件下等离子体超表面光学涡旋光束的产生和探测非技术描述：研究相位和偏振奇异现象的学科被称为奇异光学。涡旋光束表现出奇异的标量特征，在光束中心有相位奇点；极化奇异光束表现出奇异的矢量特征，只有一个未定义的偏振参数。如何在芯片上产生具有宽带宽和极化的纯涡旋光束，如何实现紧凑的线性和非线性涡旋光束转换器，以及怎样的器件能够直接识别涡旋拓扑电荷是当前奇异光学研究的挑战。为了解决这些挑战，在本研究中，利用独特设计的超薄金属纳米结构等离子体超表面作为一个强大而紧凑的平台，用于探索平面奇异光学，产生线性和非线性奇异光束，以及通过光电集成检测涡旋光束轨道角动量。这项研究为推进光通信、光束整形和转换、光电器件、光学传感和成像等领域的许多应用铺平了道路。奇异光学和超表面的研究与教育和推广活动相结合，以提高不同层次的教育，包括本科生和研究生的培训，代表性不足和女性学生的招募，女性光学学生团体组织，跨学科的超材料课程开发和K-12学生的推广活动。技术描述：本研究的目标是探索利用超薄等离子体超表面在线性和非线性条件下产生和探测光学涡旋光束，以解决开放的研究挑战，并在奇异光学领域创造新的机会，获得自旋轨道和轨道-轨道相互作用以及光学角动量守恒的基本知识。本研究采用线性和非线性光学设计与仿真、等离子体超表面样品纳米加工、光学和光电子器件表征等方法，研究了奇异光学、非线性光学和自旋轨道光子学中基于超表面的光操纵和光物质相互作用的潜在物理。该活动的智力意义包括：(1)产生纯光学涡旋光束和偏振奇异光束，推动复杂结构光操纵和拓扑奇点的研究；（ii）探索非线性等离子体超表面中二、三次谐波涡旋光束的产生和光束成形，揭示轨道角动量守恒定律，创建紧凑型非线性光束转换器和有源光子器件；（iii）在等离子体元表面上实现基于自旋和轨道霍尔效应的光电涡旋光束检测，解决片上轨道角动量检测的难题，构建基于功能元表面的光电器件。

Abstract Title: CAREER: Flat Singular Optics: Generation and Detection of Optical Vortex Beams with Plasmonic Metasurfaces in Linear and Nonlinear RegimesNontechnical Description:The study of the phenomena of phase and polarization singularities is known as singular optics. Vortex beams display singular scalar features with phase singularities in the beam center, while polarization singular beams present singular vectorial features with one undefined polarization parameter. The current open research challenges in singular optics are how to generate pure vortices with broad bandwidth and polarization singular beams on chip, how to realize compact linear and nonlinear vortex beam converters, and what kind of device enables direct identification of vortex topological charges. In order to address these challenges, in this research, uniquely designed plasmonic metasurfaces made of ultrathin metallic nanostructures are utilized as a powerful and compact platform for exploring flat singular optics, generating singular optical beams in both linear and nonlinear regimes, as well as detecting vortex beam orbital angular momentum with optoelectronic integration. This research paves the way for advancing many applications in optical communication, beam shaping and conversion, optoelectronic devices, and optical sensing and imaging. The research of singular optics and metasurfaces is integrated with education and outreach activities in order to enhance various levels of education, including undergraduate and graduate students training, underrepresented and female students recruitment, women in optics student group organization, interdisciplinary metamaterials course development and outreach activities for K-12 students. Technical Description:The goals of the research are to explore the generation and detection of optical vortex beams using ultra-thin plasmonic metasurfaces in both linear and nonlinear regimes in order to solve open research challenges and create new opportunities in singular optics, gain fundamental knowledge of spin-orbit and orbit-orbit interactions and optical angular momentum conservation. The research uses the approaches of linear and nonlinear optical design and simulation, plasmonic metasurface sample nanofabrication, optical and optoelectronic device characterizations to study the underlying physics of metasurface based light manipulation and light-matter interaction in singular optics, nonlinear optics, and spin-orbit photonics. The intellectual significance of the activity includes: (i) generation of pure optical vortex beams and polarization singular beams to advance the research of complex structured light manipulation and topological singularities; (ii) exploration of second- and third-harmonic vortex beam generation and beam shaping in nonlinear plasmonic metasurfaces to reveal the conservation law of orbital angular momentum and create compact nonlinear beam converters and active photonic devices; (iii) realization of optoelectronic vortex beam detection based on spin and orbital Hall effects in plasmonic metasurfaces to solve the challenge of on-chip orbital angular momentum detection and build functional metasurface based optoelectronic devices.