Visualization of terahertz surface waves propagation on metal foils.

Xinke Wang,Yan Zhang,Wenfeng Sun,Jiasheng Ye,Sen Wang,Peng Han,Haitao Yan,Shengfei Feng

doi:10.1038/srep18768

Xinke Wang, Yan Zhang + Show 6 more

Open Access

https://doi.org/10.1038/srep18768

Copy DOI

Abstract

Exploitation of surface plasmonic devices (SPDs) in the terahertz (THz) band is always beneficial for broadening the application potential of THz technologies. To clarify features of SPDs, a practical characterization means is essential for accurately observing the complex field distribution of a THz surface wave (TSW). Here, a THz digital holographic imaging system is employed to coherently exhibit temporal variations and spectral properties of TSWs activated by a rectangular or semicircular slit structure on metal foils. Advantages of the imaging system are comprehensively elucidated, including the exclusive measurement of TSWs and fall-off of the time consumption. Numerical simulations of experimental procedures further verify the imaging measurement accuracy. It can be anticipated that this imaging system will provide a versatile tool for analyzing the performance and principle of SPDs.

Highlights

Exploitation of surface plasmonic devices (SPDs) in the terahertz (THz) band is always beneficial for broadening the application potential of THz technologies
A THz digital holographic imaging system is utilized to characterize the temporal evolution of a THz surface wave (TSW)
(b) Two-dimensional pattern of a TSW excited by the sub-wavelength scale structure of a metal foil. (c) Orientation of the ZnTe crystal

Summary

Introduction

Exploitation of surface plasmonic devices (SPDs) in the terahertz (THz) band is always beneficial for broadening the application potential of THz technologies. The detection methods in the THz frequency range are developed on the basis of the traditional THz time domain spectroscopy, which mainly include scanning near-field THz microscopes (SNTM) utilizing a photoconductive antenna[13,14,15] or an electro-optic crystal[16,17,18,19]. A photoconductive antenna can detect the spatial derivative of a TSW and the signal obtained by an electro-optical crystal is directly proportional to the field of a TSW. Advantages of both techniques are the simultaneous acquirement of the amplitude and phase of a TSW due to the coherent measurement mode and the sub-wavelength spatial resolution. Corresponding simulation results are obtained to replicate experimental phenomena

Methods

Results

Conclusion