EAGER: A new coupling scheme for surface plasmon polaritons using structured illumination

Harvard University, Cambridge MA

Investigators

Abstract

The objective of this research is to demonstrate a new coupling technique to excite propagating surface plasmons on an unstructured metallic surface by illuminating it with structured light beams. The experimental approach is to focus light from a Titanium Sapphire laser with a cylindrical lens into a narrow diffraction limited stripe on a gold film and to image the surface plasmons by advanced near field scanning optical microscopy techniques. The theoretical approach is to use techniques such as Finite Difference Time Domain simulations for visualizing the propagating surface plasmons. The intellectual merit of this proposal is that if the proposed effect is demonstrated it will have a major impact on plasmonics. The imaging of two plane-like plasmon waves at an angle would confirm the striking resemblance between this phenomenon and Cherenkov radiation. It will lead to fundamental new understanding on the coupling of light to metallic surfaces and would introduce a completely new approach to excite them, without needing couplers such as gratings or prisms. The broader impacts of this research stem from its technological, societal and educational importance. It is important because observation of this effect could lead to new optical interconnects on a chip by introducing a simpler and easier/cheaper method. This discovery will thus positively influence on-chip optical communications, leading to significant societal impacts. The findings coming out of this project, by contributing to new basic understanding of surface plasmons and their applications, will definitely also influence the teaching of nanophotonics, including textbooks.