Ochs Maximilian, Zurak Luka, Krauss Enno, Meier Jessica, Emmerling Monika, Kullock René, Hecht Bert
NanoOptics & Biophotonics Group, Experimental Physics 5, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
Nano Lett. 2021 May 26;21(10):4225-4230. doi: 10.1021/acs.nanolett.1c00182. Epub 2021 Apr 30.
The electrical excitation of guided plasmonic modes at the nanoscale enables integration of optical nanocircuitry into nanoelectronics. In this context, exciting plasmons with a distinct modal field profile constitutes a key advantage over conventional single-mode integrated photonics. Here, we demonstrate the selective electrical excitation of the lowest-order symmetric and antisymmetric plasmonic modes in a two-wire transmission line. We achieve mode selectivity by precisely positioning nanoscale excitation sources, i.e., junctions for inelastic electron tunneling, within the respective modal field distribution. By using advanced fabrication that combines focused He-ion beam milling and dielectrophoresis, we control the location of tunnel junctions with sub-10 nm accuracy. At the far end of the two-wire transmission line, the guided plasmonic modes are converted into far-field radiation at separate spatial positions showing two distinct orthogonal polarizations. Hence, the resulting device represents the smallest electrically driven light source with directly switchable polarization states with possible applications in display technology.
纳米尺度下引导等离激元模式的电激发能够将光学纳米电路集成到纳米电子学中。在这种背景下，激发具有独特模式场分布的等离激元构成了相对于传统单模集成光子学的一个关键优势。在此，我们展示了在双线传输线中对最低阶对称和反对称等离激元模式的选择性电激发。我们通过在各自的模式场分布内精确地定位纳米级激发源，即非弹性电子隧穿结，来实现模式选择性。通过使用结合聚焦氦离子束铣削和介电电泳的先进制造工艺，我们以亚10纳米的精度控制隧道结的位置。在双线传输线的远端，引导等离激元模式在不同的空间位置被转换为远场辐射，呈现出两种不同的正交偏振。因此，所得到的器件代表了具有直接可切换偏振态的最小电驱动光源，在显示技术中可能具有应用价值。
