Abstract-Dielectric probe for scattering-type terahertz scanning near-field optical microscopy

T. Kurihara¹, K. Yamaguchi¹, H. Watanabe¹, M. Nakajima², and T. Suemoto¹

¹Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8581, Japan
²Department of Physics, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

http://apl.aip.org/resource/1/applab/v103/i15/p151105_s1?isAuthorized=no

Dielectric material was used as the probe material for a scattering-type terahertz scanning near-field optical microscope (THz S-SNOM). It was found that the dielectric probe exhibits a strong near-field scattering signal with an amplitude comparable to that of the metallic probe. The behavior of the electric near-field around the tip was calculated using the finite-difference time-domain method, showing the field enhancement comparable to that of the metallic probe. The dielectric probe also exhibited a faster temporal response compared to the response of the metallic probe. Introduction of a non-metallic probe would enlarge the application field of the THz S-SNOM technique.

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