Akademik Veri Yönetim Sistemi
Emerging Imaging and Sensing Technologies for Security and Defence VIII 2023, Amsterdam, Hollanda, 5 - 06 Eylül 2023, cilt.12740
This work consists of the generation of free-space Laguerre-Gaussian (LG) modes at millimeter-wave frequencies by use of a 3D-printed spiral phase plate and measuring the transmission capability of LG beams with respect to conventional Gaussian beams in scattering media such as wood, drywall, and rocky soil in the 1-3mm wavelength range. When a Gaussian beam of light passes through the spiral phase plate, the phase of the light is modified according to the thickness of the etched spiral pattern, resulting in an LG mode. Transmittance of LG beams at both 90GHz and 270GHz is measured with rocky soil, wood, and drywall. The results show that the frequency-dependent transmission of the beams is governed by the mode number as well as the anisotropy of the medium. A frequency-dependent improvement in transmission is observed for highly scattering media with respect to mode number. These results support recent studies that show that OAM modes are useful for measurements through anisotropic media. Their demonstration for lower orders, as shown here in the mm-wave frequency range, is exciting for applications such as the detection of concealed objects, wireless communication, and imaging in highly scattering media.