MEMS-actuated metasurface Alvarez lens.
MEMS-actuated metasurface Alvarez lens.
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DOI：
10.1038/s41378-020-00190-6
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发表时间：
2020
影响因子：
7.9
通讯作者：
Böhringer KF
中科院分区：
文献类型：
--
作者：
Han Z;Colburn S;Majumdar A;Böhringer KF
具有可调焦距的微型透镜是许多涉及紧凑型光学系统的现代应用的基本组件。虽然已经报道了具有各种调谐机制的若干可调谐透镜，但是它们通常面临关于功耗、调谐速度、制造成本或生产可扩展性的挑战。在这项工作中，我们已经适应了阿尔瓦雷斯透镜的机制-变焦距复合透镜，其中两个光学元件与立方相表面的横向位移引起的光功率的变化-构建一个微型的，微机电系统（MEMS）驱动的元表面阿尔瓦雷斯透镜。基于静电MEMS的实现以低功耗产生快速且可控的致动。与使用传统自由曲面透镜的系统相比，利用超颖表面（超颖和亚波长图案化衍射光学器件）作为光学元件极大地减小了设备体积。整个MEMS Alvarez超透镜与现代半导体制造技术完全兼容，使其具有以低单位成本大规模生产的潜力。在1550 nm波长下工作的原型中，阿尔瓦雷斯超透镜在高达20 V的直流（DC）电压应用下实现了6.3 µm的总单轴位移，这在68 µm的总调谐范围内调制了焦点位置，产生了超过一个数量级的焦距变化和1460屈光度的光焦度变化。MEMS Alvarez超透镜具有强大的设计，可以在不大幅增加器件体积或能耗的情况下产生更大的调谐范围，因此适用于各种成像和显示应用。美国的研究人员已经开发出一种微型透镜，它可以快速改变焦距，而且耗电量很低。该装置基于阿尔瓦雷斯透镜设计，其中两个光学元件的移动改变光焦度。一个普通的阿尔瓦雷斯透镜使用具有匹配曲面的元件，但是华盛顿大学的韩哲一和她的合著者调整了设计，使用超曲面光学器件。超表面提供与普通透镜元件相同的效果，但是是平的和薄的，使得更容易将它们并入微型装置中。该团队使用MEMS系统来移动元表面元件，使它们能够在20 V以下的应用下实现1460屈光度的变化。这种方法在制造用于超紧凑用途的可调透镜中将是有用的，例如内窥镜检查和移动的设备。
Miniature lenses with a tunable focus are essential components for many modern applications involving compact optical systems. While several tunable lenses have been reported with various tuning mechanisms, they often face challenges with respect to power consumption, tuning speed, fabrication cost, or production scalability. In this work, we have adapted the mechanism of an Alvarez lens – a varifocal composite lens in which lateral shifts of two optical elements with cubic phase surfaces give rise to a change in the optical power – to construct a miniature, microelectromechanical system (MEMS)-actuated metasurface Alvarez lens. Implementation based on an electrostatic MEMS generates fast and controllable actuation with low power consumption. The utilization of metasurfaces – ultrathin and subwavelength-patterned diffractive optics – as optical elements greatly reduces the device volume compared to systems using conventional freeform lenses. The entire MEMS Alvarez metalens is fully compatible with modern semiconductor fabrication technologies, granting it the potential to be mass-produced at a low unit cost. In the reported prototype operating at 1550 nm wavelength, a total uniaxial displacement of 6.3 µm was achieved in the Alvarez metalens with a direct-current (DC) voltage application up to 20 V, which modulated the focal position within a total tuning range of 68 µm, producing more than an order of magnitude change in the focal length and a 1460-diopter change in the optical power. The MEMS Alvarez metalens has a robust design that can potentially generate a much larger tuning range without substantially increasing the device volume or energy consumption, making it desirable for a wide range of imaging and display applications. Researchers in the United States have developed a miniature lens which can change focal length quickly and with low power usage. The device is based on the Alvarez lens design in which the movement of two optical elements changes the optical power. A normal Alvarez lens uses elements with matching curved surfaces, but Zheyi Han and her co-authors at the University of Washington adjusted the design to use metasurface optics instead. Metasurfaces provide the same effect as normal lens elements but are flat and thin, making it easier to incorporate them in miniature devices. The team used a MEMS system to move the metasurface elements, enabling them to achieve a 1460-diopter change with the application of under 20V. This approach will be useful in fabricating tunable lenses for ultra-compact uses, such as endoscopy and mobile devices.
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影响因子：
16.6
作者：
Arbabi E;Arbabi A;Kamali SM;Horie Y;Faraji-Dana M;Faraon A
通讯作者：
Faraon A
影响因子：
10.4
作者：
Colburn, Shane;Zhan, Alan;Majumdar, Arka
通讯作者：
Majumdar, Arka
影响因子：
4.6
作者：
Lin D;Melli M;Poliakov E;Hilaire PS;Dhuey S;Peroz C;Cabrini S;Brongersma M;Klug M
通讯作者：
Klug M
影响因子：
2.3
作者：
Legtenberg, R;Groeneveld, AW;Elwenspoek, M
通讯作者：
Elwenspoek, M
影响因子：
7
作者：
Colburn, Shane;Majumdar, Arka
通讯作者：
Majumdar, Arka