Frank Bettina, Kahl Philip, Podbiel Daniel, Spektor Grisha, Orenstein Meir, Fu Liwei, Weiss Thomas, Horn-von Hoegen Michael, Davis Timothy J, Meyer Zu Heringdorf Frank-J, Giessen Harald
4th Physics Institute and Stuttgart Research Center of Photonic Engineering, University of Stuttgart, 70569 Stuttgart, Germany.
Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1-21, 47057 Duisburg, Germany.
Sci Adv. 2017 Jul 12;3(7):e1700721. doi: 10.1126/sciadv.1700721. eCollection 2017 Jul.
We experimentally and theoretically visualize the propagation of short-range surface plasmon polaritons using atomically flat single-crystalline gold platelets on silicon substrates. We study their excitation and subfemtosecond dynamics via normal-incidence two-photon photoemission electron microscopy. By milling a plasmonic disk and grating structure into a single-crystalline gold platelet, we observe nanofocusing of the short-range surface plasmon polariton. Localized two-photon ultrafast electron emission from a spot with a smallest dimension of 60 nm is observed. Our novel approach opens the door toward reproducible plasmonic nanofocusing devices, which do not degrade upon high light intensity or heating due to the atomically flat surface without any tips, protrusions, or holes. Our nanofoci could also be used as local emitters for ultrafast electron bunches in time-resolved electron microscopes.
我们通过实验和理论方法，利用硅衬底上原子级平整的单晶金薄片，可视化了短程表面等离激元极化激元的传播。我们通过正入射双光子光发射电子显微镜研究了它们的激发和亚飞秒动力学。通过在单晶金薄片上铣出一个等离激元盘和光栅结构，我们观察到了短程表面等离激元极化激元的纳米聚焦。观察到了来自最小尺寸为60纳米的光斑的局域双光子超快电子发射。我们的新方法为可重复的等离激元纳米聚焦器件打开了大门，由于其原子级平整的表面没有任何尖端、凸起或孔洞，这些器件在高光强度或加热时不会退化。我们的纳米焦点还可以用作时间分辨电子显微镜中超快电子束的局域发射器。
