Abstract

We experimentally demonstrate complete two-dimensional (2-D) confinement of terahertz (THz) energy in finite-width parallel-plate waveguides, defying conventional wisdom in the century-old field of microwave waveguide technology. We find that the degree of energy confinement increases exponentially with decreasing plate separation. We propose that this 2-D confinement is mediated by the mutual coupling of plasmonic edge modes, analogous to that observed in slot waveguides at optical wavelengths. By adiabatically tapering the width and the separation, we focus THz waves down to a size of 10 μm (≈λ/260) by 18 μm (≈λ/145), which corresponds to a mode area of only 2.6 × 10⁻⁵ λ².

© 2010 OSA

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History
Original Manuscript: February 23, 2010
Manuscript Accepted: April 21, 2010
Revised Manuscript: April 20, 2010
Published: April 23, 2010

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Author Affiliations

Hui Zhan, Rajind Mendis, Daniel M. Mittleman

Department of Electrical and Computer Engineering, MS-366, Rice University, Houston, Texas 77251, USA

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