A Broadband Dual-Polarized Low-NEP SiGe HBT Terahertz Direct Detector for Polarization-Sensitive Imaging

A broadband silicon-integrated dual-polarized antenna-coupled THz direct detector with a minimum NEP of 2.7 pW/root Hz at 450 GHz and 16 pW/root Hz at 850 GHz is implemented in a 4-mirror focussed imaging setup, demonstrating polarization-sensitive imaging at 852 GHz. Polarization-sensitive images are computed through the Stokes vector formulation. Based on the degree of linear polarization, finer local physical fingerprints of an imprinted Teflon object are revealed.