Controlled polarization in plasmons propagating from metal into semiconductors in multicomponent nanowires

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

ABSTRACT: Objective: We have studied the propagation of light in nanoscale wires comprising a metal segment and a semiconducting segment, and we have observed that efficient electrical and optical coupling can be achieved between these two segments. We posit that tailoring the shape of the junction will control the polarization rotation of the light emitted from the distal semiconducting end of the nanowire relative to incident light coupled into the metal end of the nanowire. Our time-domain simulations reproduce many of our preliminary observations. We propose to optimize the asymmetric metal-semiconductor junctions for electrical and optical transport, and we describe a series of preliminary chemical sensing experiments. Intellectual Merit: Propagation of plasmons in single-component metal nanowires is well understood, but propagation between different materials is still being explored. Control of polarization in such structures can be critical to the design of larger scale devices, but manipulation of the polarization in such structures is essentially untouched as a research field. This project will explore these areas, and will study potential sensing applications of this polarization rotation. Broader Impact: Fundamental understanding and control of polarization in nanoscale photonic systems will have broad potential impacts in the technology of national security and communications. Sensing of pollutants and toxins has obvious importance in society and national security and experiments here may inform new methods of nanoscale sensors. In addition this project will focus on the recruitment of both undergraduate and graduate students from under-represented groups (NSF-AGEP, SMART, eg).