Institute of Optics and Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
Phys Rev Lett. 2011 Jun 3;106(22):226802. doi: 10.1103/PhysRevLett.106.226802. Epub 2011 Jun 2.
We exploit a plasmon mediated two-step momentum down-conversion scheme to convert low-energy tunneling electrons into propagating photons. Surface plasmon polaritons (SPPs) propagating along an extended gold nanowire are excited on one end by low-energy electron tunneling and are then converted to free-propagating photons at the other end. The separation of excitation and outcoupling proves that tunneling electrons excite gap plasmons that subsequently couple to propagating plasmons. Our work shows that electron tunneling provides a nonoptical, voltage-controlled, and low-energy pathway for launching SPPs in nanostructures, such as plasmonic waveguides.
我们利用等离子体介导的两步动量下转换方案将低能隧穿电子转换为传播光子。表面等离激元（SPP）沿扩展的金纳米线传播，在一端通过低能电子隧穿激发，然后在另一端转换为自由传播的光子。激发和输出的分离证明，隧穿电子激发间隙等离子体，随后与传播等离子体耦合。我们的工作表明，电子隧穿为在纳米结构中发射 SPP 提供了一种非光学、电压控制和低能量的途径，例如等离子体波导。
