Abstract
Terahertz (THz) pulses are applied in areas as diverse as materials science, communication and biosensing. Techniques for subwavelength concentration of THz pulses give access to a rapidly growing range of spatial scales and field intensities. Here we experimentally demonstrate a method to generate intense THz pulses on a metal wire, thereby introducing the possibility of wave-guiding and focussing of the full THz pulse energy to subwavelength spotsizes. This enables endoscopic sensing, single-shot subwavelength THz imaging and study of strongly nonlinear THz phenomena. We generate THz surface plasmon polaritons (SPPs) by launching electron bunches onto the tip of a bare metal wire. Bunches with 160 pC charge and ≈6 ps duration yield SPPs with 6–10 ps duration and 0.4±0.1 MV m−1 electric field strength on a 1.5 mm diameter aluminium wire. These are the most intense SPPs reported on a wire. The SPPs are shown to propagate around a 90° bend.
Highlights
Terahertz (THz) pulses are applied in areas as diverse as materials science, communication and biosensing
In 2008, we proposed a method in which ultrashort bunches of relativistic electrons generate coherent transition radiation (CTR) at the tip of a thin wire[34]
The basic principle of using an ultrashort bunch of relativistic electrons to produce CTR at the tip of a thin wire, which subsequently propagates along the wire as a powerful surface plasmon polaritons (SPPs), is illustrated in Fig. 1 and is explained in more detail in the Methods section
Summary
Terahertz (THz) pulses are applied in areas as diverse as materials science, communication and biosensing. We experimentally demonstrate a method to generate intense THz pulses on a metal wire, thereby introducing the possibility of wave-guiding and focussing of the full THz pulse energy to subwavelength spotsizes This enables endoscopic sensing, single-shot subwavelength THz imaging and study of strongly nonlinear THz phenomena. The radiation produced propagates as a powerful SPP along the wire, which serves as a waveguide This hybrid technique integrates accelerator-based CTR methods and plasmonic techniques to produce intense subcycle pulses in the THz frequency range directly on a bare metal wire waveguide[34]. The estimated peak electric field strength E of the SPP generated on the wire is given by
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
