Demonstration of photonics-based D-band integrated localization and communication.

The terahertz spectrum has the ability to provide high-speed communication and millimeter-level resolution. As a result, terahertz-integrated sensing and communication (ISAC) has been identified as a key enabler for 6G wireless networks. This work discusses a photonics-based D-band communication system for integrated high-resolution localization and high-speed wireless communication. Our empirical results show that a communication rate of 5 Gbps over a distance of 1.5 m and location identification of the target with millimeter-level (<4m m) range resolution can be conducted simultaneously using the same signal. We also show that the error due to the thickness of the beam splitter can be eliminated, while the quantization error and the random drift errors are the limiting factors of the resolution achieved. This experimental demonstration using D-band communication indicates that terahertz ISAC can be realized for 6G networks while considering the underlying system restrictions (e.g., bandwidth limit and lens diameter).

Terahertz imaging: a diagnostic technology for prevention of grass seed infestation.

One of the most significant problems the Australian sheep and lamb industry faces today is grass seed infestation (GSI), which occurs when seeds accumulate in the sheep's fleece and penetrate the skin, causing infection. Meat & Livestock Australia estimates that the yearly losses caused due to GSI are around AUD$47.5 M (in Australia alone). Here, we demonstrate that terahertz spectroscopy and imaging can be utilized for early detection of GSI. This is possible because terahertz waves can penetrate through sheep wool and have the appropriate wavelength for identifying the seed. Moreover, terahertz waves have non-invasive and non-ionizing properties and are ideal for non-contact and standoff detection. This work demonstrates that terahertz waves can be utilized for the early detection of seeds in the animal fleece or on the pelt as a precursor tool for the prevention of GSI.

20 dB improvement utilizing custom-designed 3D-printed terahertz horn coupler.

Terahertz band is envisaged to provide substantially higher capacity and much lower latency for wireless communications in contrast to microwave frequencies. Moving to higher frequencies comes with its own unique challenges to be addressed, such as poor coupling efficiency from free space into and out of planar air-core waveguides. Here, we propose a framework for rapid design and low-cost fabrication of terahertz horn couplers. The horn couplers are first designed by maximizing the field overlap integral on apex and aperture interfaces, then fabricated exploiting 3D printing technique, and finally sputtered with a thin layer of gold. A 28~µm standard deviation of the surface roughness height of the 3D printed horn couplers is calculated. Experimental demonstrations show that the proposed horn coupler improves the transmittance of a hybrid photonic crystal waveguide by 20 dB in comparison with the previous pinhole-based coupling configuration. This work provides a fast, convenient and economical approach for design and fabrication of customized couplers for any waveguide size, with a cost of only 5% of commercially available counterparts, and could be integrated in 3D-printed terahertz devices during fabrication.