Abstract-Subsurface Nanoimaging by Broadband Terahertz Pulse Near-Field Microscopy

Kiwon Moon , Hongkyu Park , Jeonghoi Kim ,Youngwoong Do , Soonsung Lee , Gyuseok Lee ,Hyeona Kang , and Haewook Han *

Department of Electrical and Computer Engineering,POSTECH, San 31, Hyoja-dong, Nam-gu, Pohang, Kyungbuk 790-784, Korea

Nano Lett., Article ASAP

DOI: 10.1021/nl503998v

Publication Date (Web): December 1, 2014

Copyright © 2014 American Chemical Society

*E-mail: hhan@postech.ac.kr.

http://pubs.acs.org/doi/abs/10.1021/nl503998v?src=recsys

Combined with terahertz (THz) time-domain spectroscopy, THz near-field microscopy based on an atomic force microscope is a technique that, while challenging to implement, is invaluable for probing low-energy light-matter interactions of solid-state and biomolecular nanostructures, which are usually embedded in background media. Here, we experimentally demonstrate a broadband THz pulse near-field microscope that provides subsurface nanoimaging of a metallic grating embedded in a dielectric film. The THz near-field microscope can obtain broadband nanoimaging of the subsurface grating with a nearly frequency-independent lateral resolution of 90 nm, corresponding to ∼λ/3300, at 1 THz, while the AFM only provides a flat surface topography.