Analysis and design of a microprobe for near-field scanning terahertz microscopy

We study the existence and guidance feasibility of spoof surface plasmon polaritons on a corrugated conical copper wire at terahertz frequencies. Then, we propose a microprobe so it can localize the field with high concentration at the apex and interacts strongly with samples, here, gold strips located nearby. Finally, we examine imaging functionality of the probe, and find that sub-wavelength resolution well beyond diffraction limit is possible.