Broadband black coating for terahertz radiometry

We report an easy fabricated, broadband and high-absorbance coating for terahertz radiometry. The spectral properties of this coating in THz region were characterized with a home-made terahertz time-domain spectrometer. The measured spectral reflectance is less than 0.3% ranging from 0.2 THz to 0.5 THz and less than 0.1% ranging from 0.5 THz to 2.0 THz.