High-Speed 600 GHz-Band Terahertz Imaging Scanner System with Enhanced Focal Depth

Abstract

Lenses/mirrors with fast data acquisition speeds and extended focal depths have practical importance in terahertz (THz) imaging systems. Thus, a high-speed 600 GHz-band THz imaging scanner system with enhanced focal depth is presented in this work. A polygon mirror with a 250 Hz scanning frequency and an integrated off-axis parabolic (OAP) mirror with an ~170 mm focal depth were employed for 2D imaging. The simulation and experimental results show that a spatial resolution of ~2 mm can be achieved as the imaging distance varies from ~85 to 255 mm. The proposed system was applied to image a hidden metal object as a potential security application, demonstrating that this system can image targets with an enhanced focal depth.

Photonic Radar for 3D Imaging: From Millimeter to Terahertz Waves

“…However, when the imaging range of interest is small, such as estimating the µm-order thickness of a coating material in the THz band, a cm-order DOF is sufficient. In addition, an advanced lens design can further extend the DOF while maintaining high spatial resolution [66], [67].…”