Publications by authors named "W Withayachumnankul"

We observe that the modal field distribution of a dielectric slot waveguide closely resembles a magnetic dipole antenna. Such an aperture distribution traditionally demands metals, making it ill-suited to high frequencies due to excessive ohmic loss. By terminating a dielectric slot waveguide with a matched free-space interface, a compact all-dielectric radiating magnetic dipole is realized.

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Resonant cavities are fundamental to and versatile for terahertz integrated systems. So far, integrated resonant cavities have been implemented in relatively lossy terahertz platforms. In this Letter, we propose a series of integrated disk resonators built into a low-loss substrateless silicon waveguide platform, where the resonances and associated quality factor (Q-factor) can be controlled via an effective medium.

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A uniform illumination over a screen is crucial for terahertz imaging. As such, conversion from a Gaussian beam to a flattop beam becomes necessary. Most of the current beam conversion techniques rely on bulky multi-lens systems for collimated input and operate in the far-field.

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Two plasma filaments crossing above the target create a subwavelength window for terahertz microscopy that excludes any subwavelength probe in vicinity.

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All-silicon effective-medium-clad waveguides are a promising candidate for an integrated terahertz platform with high efficiency and broad bandwidth. Waveguide crossings are essential circuit components, allowing for wave routing over shorter paths to increase circuit density. However, the simple intersection of two orthogonal effective-medium-clad waveguides results in terahertz wave scattering, leading to relatively high cross talk.

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