earticle

영어

Report on the propagation characteristics of terahertz (THz) dielectric slab waveguides affected by laterally misaligned coupling conditions. The TM₀ mode is effectively launched when THz waves are coupled near the lateral center of the waveguide, On the other hand, if the coupling position is shifted laterally, higher-order asymmetric modes such as TM₁ and TM₃ become dominant. The coupling of incident THz waves at the center results in leaky mode behavior for longer wavelengths, whereas shorter wavelengths remain guided. In contrast, off-center coupling induces leaky mode characteristics over nearly the entire spectral ranges. These differences are distinguishable in the time-domain signals measured by THz time-domain spectroscopy, thus allowing the implementation of a time-domain prism for spectroscopy. The systematic investigation of THz slab waveguides may contribute to the realization of multifunctional optical devices for Tz sensing, imaging, and high-speed wireless communications, as well as to the analysis of optical properties in THz measurement systems.