A new research paper titled “3D-Printed Multimode-Interference-Based Bessel Beamformer for Terahertz Dielectric Waveguides” has been published by the Grupo de Optoelectronica y Tecnología Láser (GOTL) in IEEE Microwave and Wireless Technology Letters (Early Access).
The study, led by Ashish Kumar (Universidad Carlos III de Madrid), presents an innovative approach to generating Bessel beams in the terahertz (THz) frequency range using 3D-printed multimode interference (MMI) structures. Unlike conventional techniques that rely on bulky free-space optical setups, this work introduces a compact and scalable solution based on dielectric waveguides.
The proposed beamformer utilizes a cyclic-olefin-copolymer (COC) MMI structure combined with a λ/4 slot-waveguide termination, enabling efficient coupling and low reflection. Experimental results demonstrate a transmission efficiency of 93.9% at 275 GHz, with stable beam propagation over distances up to 35 mm, maintaining significant efficiency even at extended ranges.
This approach provides a practical and cost-effective method for generating non-diffracting beams in guided-wave THz systems, addressing key limitations of existing solutions.
The work was carried out through the collaboration of Ashish Kumar, Surya Revanth, Muhsin Ali, Irmantas Kasalynas, Daniel Headland, and Guillermo Carpintero, bringing together expertise across multiple institutions.
Experimental characterization was supported by the Center for Physical Sciences and Technology (FTMC) in Vilnius, whose facilities played a key role in validating the results.
This research has received support from several European projects, including TERAOPTICS ITN-MSC, SPRINTER, TERA6G and POLYNICES.
Read the full publication here.