Abstract-A 90°-Inclined Linearly Polarized Probe for Terahertz Mueller Imaging

Xuexuan Ruan,  Kung Bo Ng, Huan Yi, Shi-Wei Qu, Chi Hou Chan, 

https://ieeexplore.ieee.org/document/8740178

A novel terahertz (THz) probe, consisting of a 90°-inclined linearly polarized (LP) component incorporated with a pyramidal-shaped TE 10 mode rectangular open-ended waveguide (OEWG), is introduced in this paper. The pyramidal feed, located beneath the substrate, is made of brass plated with gold. The radiation component, placed on tip of the OEWG, is achieved by standard printed-circuit and plated-through-hole techniques. Measurement results demonstrate that the proposed probe possesses an impedance bandwidth (VSWR ≤ 2) of better than 18.5% from lower than 270 to higher than 325 GHz. In the impedance bandwidth, the measured gain is from 7.2 to 8.2 dBi and all radiation patterns are relatively symmetric with relatively small back radiation and cross-polarization levels. The proposed probe is a potential component for Mueller imaging at THz frequencies.

Abstract-Prototyping of Terahertz Metasurface by One-step Lithographically Defined Templating

 Shaolin Zhou,  Songlin Mu,  Salahuddin Raju, Clarissa Prawoto,  Xuexuan Ruan,  KungBo Ng, Mansun Chan,

https://ieeexplore.ieee.org/document/8340782/

To bypass the sophisticated procedure in existing techniques to produce the terahertz (THz) metasurface filter, a one-step lithographically defined templating method is proposed for rapid prototyping. Essentially, a simplified photolithography process is exploited and optimized first to release one freestanding template perforated with desired features, without any sacrificial layer or external force. The key idea is to impart an adequate degree of hydrophobicity to substrate to tune adhesion between substrate and template for a spontaneous release. Then the template-directed metallization by electroless plating gives rise to an intact freestanding metal mesh framework of THz metasurface filter. Spectral characterization by the THz frequency-domain spectroscopy shows good spectral selection behavior, which agrees adequately well with the numerical simulation by HFSS.