Schnell M, Carney P S, Hillenbrand R
CIC nanoGUNE Consolider, 20018 Donostia-San Sebastian, Spain.
Department of Electrical and Computer Engineering and The Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, Illinois 61801, USA.
Nat Commun. 2014 Mar 20;5:3499. doi: 10.1038/ncomms4499.
Holography has paved the way for phase imaging in a variety of wide-field techniques, including electron, X-ray and optical microscopy. In scanning optical microscopy, however, the serial fashion of image acquisition seems to challenge a direct implementation of traditional holography. Here we introduce synthetic optical holography (SOH) for quantitative phase-resolved imaging in scanning optical microscopy. It uniquely combines fast phase imaging, technical simplicity and simultaneous operation at visible and infrared frequencies with a single reference arm. We demonstrate SOH with a scattering-type scanning near-field optical microscope (s-SNOM) where it enables reliable quantitative phase-resolved near-field imaging with unprecedented speed. We apply these capabilities to nanoscale, non-invasive and rapid screening of grain boundaries in CVD-grown graphene, by recording 65 kilopixel near-field images in 26 s and 2.3 megapixel images in 13 min. Beyond s-SNOM, the SOH concept could boost the implementation of holography in other scanning imaging applications such as confocal microscopy.
全息术为包括电子显微镜、X射线显微镜和光学显微镜在内的各种宽视场技术中的相位成像铺平了道路。然而，在扫描光学显微镜中，图像采集的串行方式似乎对传统全息术的直接实现构成了挑战。在此，我们介绍用于扫描光学显微镜中定量相位分辨成像的合成光学全息术（SOH）。它独特地将快速相位成像、技术简单性以及在可见光和红外频率下使用单个参考臂同时运行结合在一起。我们用散射型扫描近场光学显微镜（s-SNOM）展示了SOH，它能够以前所未有的速度实现可靠的定量相位分辨近场成像。我们通过在26秒内记录65千像素的近场图像以及在13分钟内记录230万像素的图像，将这些能力应用于对化学气相沉积生长的石墨烯中的晶界进行纳米级、非侵入性和快速筛选。除了s-SNOM之外，SOH概念还可以推动全息术在其他扫描成像应用（如共聚焦显微镜）中的实现。
