Abstract-Multiplexing THz vortex beams with a single diffractive 3D printed lens

Federico Machado,  Przemyslaw Zagrajek, Vicente Ferrando, Juan A. A. Monsoriu,  Walter D. Furlan


https://ieeexplore.ieee.org/document/8550797

We present a novel method for experimentally generating multiplexed THz vortex beams by using a single 3D printed element that combines a set of radially distributed spiral phase plates, and a binary focusing Fresnel lens. With this element we have experimentally demonstrated that THz multiplexing can be tailored to fit within a small space on an optical bench. Results are presented beside numerical simulations, demonstrating the robust nature of the experimental method.

Abstract-Electric Properties of Graphene-Based Conductive Layers from DC Up To Terahertz Range

Pawel Kopyt, Bartlomiej Salski ; Przemyslaw Zagrajek ; Daniel Janczak ; Marcin Sloma ; Malgorzata Jakubowska ; Marzena Olszewska-Placha ; Wojciech Gwarek

http://ieeexplore.ieee.org/xpl/abstractAuthors.jsp?reload=true&tp=&arnumber=7463081&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D7463081

This paper describes results obtained using a hybrid measurement methodology employed to investigate electric properties of thin conductive layers based on graphene nanoplatelets in the frequency band spanning from dc up to terahertz range. As many as four different measurement methods were employed to cover the band of interest, including the terahertz time-domain spectroscopy and the Fourier-transform infrared spectroscopy besides resonator techniques applicable in the microwave band and the four-point dc technique. Raw measurement data obtained using these approaches were processed and based on the results a relationship between frequency and sheet resistance for various types of new graphene-based conductive layers was extracted. Eventually, several models that help to explain the observed behavior of each of the analyzed conductive inks were proposed.