Radial Distortion in Silicon Lens-Integrated THz Cameras
Silicon lenses are widely employed to turn a terahertz (THz) focal-plane array into a THz camera. For the first time, we have identified the type of radial distortion caused by such lenses. To this end, we measured all single-pixel far-field radiation patterns of a 15-mm diameter 2.75-mm extended hemispherical silicon lens-integrated 32×32-pixel CMOS camera at 0.652 THz. From this, a beam incidence angle grid has been generated, indicating barrel distortion. The measured beam incidence angle is compared to a previously published closed-form relation between scan angle and feed position for extended hemispherical lenses. The presented results are essential for all beam switching applications based on dielectric extended hemispherical lenses with an elliptical extension realized in the lens center.
This document is the accepted manuscript version that has been published in final form in: 2021 46th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) at https://doi.org/10.1109/IRMMW-THz50926.2021.9567497.
© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.