OP: Spatial Light Modulation using Reconfigurable Phase Change Material Metasurfaces

OP：使用可重构相变材料超表面进行空间光调制

• 批准号: 2003509
• 负责人: Arka Majumdar
• 金额: $ 36万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003509&HistoricalAwards=false
• 关键词: OP; Spatial; Light; Modulation; using

Many emerging applications, including autonomous driving, augmented reality visors and glass-free 3D displays rely on optical beam steering. While most existing solutions rely on mechanical movements, such as rotating a light source on top of a driverless cars, such moving parts require a large amount of energy and often limits reliability and speed. Steering light without moving parts can be extremely energy efficient, fast, and with virtually an infinite lifetime. At the heart of such a non-mechanical beam scanning technology is an optical phase shifter: a device that changes the optical path length by changing the refractive index of the material. Unfortunately, the index change of most existing materials is very small. This project aims to explore a new class of materials, called phase-change materials, which can provide almost 1000 times larger index change compared to most known materials. Moreover, the change is non-volatile, i.e., once the material is changed, the state is retained. This can reduce the energy consumption, and the complexity of the control circuit. Such materials are already being explored in the electronics community to create next-generation flash memory. This project, however, studies the optoelectronic properties of this material. To further enhance the phase shift, the project is developing hair-thin optical structures, also known as metasurfaces. These metasurfaces consist of millions of nanoscale structures that can modify incident light, and by making these structures out of phase-change materials the light beam can be steered. Along with advancing the current state of optical beam steering, this project trains a diverse, interdisciplinary workforce on novel material characterization, as well as design and nanofabrication of optical nanostructures.Shaping an optical wavefront with sub-wavelength spatial resolution is important for various applications with far-reaching scientific and technological impacts (e.g., in adaptive optics and imaging through turbid, disordered media) and commercial interests (e.g., Light Detection and Ranging for autonomous transportation and pixelated holography). The primary enabling technology for such capability is a compact optical phase shifter, which can change the phase of the incident light by a full 360 degrees at low energy (pico-Joule) and high frequency (MHz). Existing tunable optical technologies cannot provide this functionality; mechanically tunable modulators can reach a speed of only a few kHz, whereas liquid-crystal based modulators operate at 100’s of Hz. The pixel size of the spatial light modulator is also on the order of tens of wavelengths, which increases the energy consumption per pixel. To that end, this project studies emerging, non-volatile, chalcogenide-based phase-change materials and nanophotonic metasurface architectures with the goal of creating fast, low-power spatial light modulators. The sub-wavelength scatterers in a metasurface enable mapping complex curvatures onto a flat, wavelength-scale thick surface by converting them into a discretized spatial phase profile. In addition to their compact size and weight, metasurfaces are fabricated using a single-step lithography procedure with mature, highly scalable nanofabrication technology developed by the semiconductor industry. Phase-change materials can provide a large, non-volatile change in their refractive index with minimal crosstalk between neighboring pixels, as the transition only happens when a certain threshold temperature is reached. The non-volatile change also can significantly simplify the control complexity of spatial light modulators. This project combines numerical electromagnetic simulation of metasurfaces, nanofabrication, and characterization of phase-change materials and their phase transitions. The research team is developing novel metamolecule pixels and metasurface architectures and characterizing new non-volatile phase-change materials to demonstrate electronic reconfiguration of metasurfaces. This research on novel phase-change materials and their electronic reconfiguration are important to enhance our understanding of these materials and add new materials to the gamut of reconfigurable optoelectronic materials. Enhancing optical phase shifts via metamolecules and optical resonators can uncover fundamentally new knowledge on tunable nanophotonic structures and their design principles. Such design principles can be easily translated to other tunable photonic materials.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.

许多新兴应用，包括自动驾驶、增强现实遮阳板和裸眼 3D 显示器都依赖于光束控制，而大多数现有解决方案依赖于机械运动，例如旋转无人驾驶汽车顶部的光源，但此类移动部件需要一个驱动器。这种非机械光束扫描技术的核心是一种高效的光学移相器，它需要大量的能量，并且通常会限制可靠性和速度。改变光路长度的装置不幸的是，大多数现有材料的折射率变化非常小，该项目旨在探索一种称为相变材料的新型材料，它可以提供比现有材料大近 1000 倍的折射率变化。而且，这种变化是非易失性的，即一旦材料发生变化，状态就会被保留，这可以减少能量消耗，并且电子学中已经在探索这种材料。社区创造下一代然而，该项目研究了这种材料的光电特性，该项目正在开发细如发丝的光学结构，也称为超表面，这些超表面由数百万个可以改变入射的纳米级结构组成。通过用相变材料制造这些结构，可以控制光束，同时推进光束控制的当前状态，该项目培训了新型材料表征以及设计和纳米制造方面的多元化、跨学科的劳动力。光学的塑造具有亚波长空间分辨率的光学波前对于具有深远科学和技术影响（例如，通过浑浊、无序介质的自适应光学和成像）和商业利益（例如，光探测和测距）的各种应用非常重要。实现这种功能的主要技术是紧凑型光学移相器，它可以在低能量下将入射光的相位改变 360 度。现有的可调谐光学技术无法提供此功能；机械可调谐调制器只能达到几 kHz 的速度，而基于液晶的调制器则以 100 Hz 的像素大小运行。空间光调制器也有数十个波长，这增加了每个像素的能耗为此，该项目研究了新兴的非易失性、基于硫族化物的相变材料和纳米光子超表面结构，其目标是创建快速、低功耗的空间光调制器超表面中的亚波长散射体可以将复杂的曲率转换为平坦的、波长级的厚表面。除了尺寸和重量紧凑之外，超表面还采用单步光刻程序以及半导体行业开发的成熟、高度可扩展的纳米加工技术来制造。相变材料可以提供较大的、非易失性的折射率变化，同时相邻像素之间的串扰最小，因为这种转变仅在达到特定阈值温度时发生。这种非易失性变化还可以显着简化控制复杂性。该项目结合了超表面的数值电磁模拟、纳米加工以及相变材料及其相变的表征，正在开发新型超分子像素和超表面结构，并表征新的超表面结构。非挥发性相变材料来证明超表面的电子重构，这种对新型相变材料及其电子重构的研究对于增强我们对这些材料的理解以及在增强光学相位的领域中添加新材料具有重要意义。通过超分子和光学谐振器的转变可以揭示有关可调谐纳米光子结构及其设计原理的全新知识。这种设计原理可以很容易地转化为其他可调谐光子材料。该奖项反映了这一点。通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。

项目成果

1D Self-Healing Beams in Integrated Silicon Photonics

集成硅光子学中的一维自愈光束

• DOI: 10.1021/acsphotonics.1c00581
• 发表时间: 2021-03-23
• 期刊: American journal of ophthalmology
• 影响因子: 4.2
• 作者: Zhuoran Fang;Rui Chen;A. Ryou;A. Majumdar
• 通讯作者: A. Majumdar

2D beam shaping via 1D spatial light modulator using static phase masks

使用静态相位掩模通过 1D 空间光调制器进行 2D 光束整形

• DOI: 10.1364/ol.419419
• 发表时间: 2021-05
• 期刊: Optics Letters
• 影响因子: 3.6
• 作者: Whitehead, James E. M.;Ryou, Albert;Colburn, Shane;Zhelyeznyakov, Maksym;Majumdar, Arka
• 通讯作者: Majumdar, Arka

Non-volatile reconfigurable metasurface for free-space phase-only modulation

用于自由空间纯相位调制的非易失性可重构超表面

• DOI: 10.1364/cleo_si.2023.sm2g.5
• 发表时间: 2023-01
• 期刊: Optica Publishing Group
• 作者: Fang, Zhuoran;Chen, Rui;Fröch, Johannes E.;Tanguy, Quentin;Khan, Asir Intisar;Wu, Xiangjin;Mana, Arnab;Sharp, David;Munley, Christopher;Reynolds, Matthew;et al
• 通讯作者: et al

Myths and truths about optical phase change materials: A perspective

关于光学相变材料的神话与真相：一个视角

• DOI: 10.1063/5.0054114
• 发表时间: 2021-05-24
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Yifei Zhang;C. Ríos;M. Shalaginov;Mo Li;A. Majumdar;T. Gu;Juejun Hu
• 通讯作者: Juejun Hu

Roadmap for phase change materials in photonics and beyond

光子学及其他领域的相变材料路线图

• DOI: 10.1016/j.isci.2023.107946
• 发表时间: 2023-10-20
• 期刊: iScience
• 影响因子: 5.8
• 作者: Prabhathan, Patinharekandy;Sreekanth, Kandammathe Valiyaveedu;Teng, Jinghua;Ko, Joo Hwan;Yoo, Young Jin;Jeong, Hyeon-Ho;Lee, Yubin;Zhang, Shoujun;Cao, Tun;Popescu, Cosmin-Constantin;Mills, Brian;Gu, Tian;Fang, Zhuoran;Chen, Rui;Tong, Hao;Wang, Yi;He, Qiang;Lu, Yitao;Liu, Zhiyuan;Yu, Han;Mandal, Avik;Cui, Yihao;Ansari, Abbas Sheikh;Bhingardive, Viraj;Kang, Myungkoo;Lai, Choon Kong;Merklein, Moritz;Mueller, Maximilian J.;Song, Young Min;Tian, Zhen;Hu, Juejun;Losurdo, Maria;Majumdar, Arka;Miao, Xiangshui;Chen, Xiao;Gholipour, Behrad;Richardson, Kathleen A.;Eggleton, Benjamin J.;Sharda, Kanudha;Wuttig, Matthias;Singh, Ranjan
• 通讯作者: Singh, Ranjan