Terahertz imaging of biological samples

A transmission-mode measurement for CW THz imaging of polyethylene cylinder and cross-seciton of tooth is conducted using BWO. The beam profile of THz beam generated by a BWO was measured at the focal plane of a CW imaging system and the effect of electrically-large polyethylene cylinder on the beam profile examined. It was found that the focused beam becomes astigmatic and has more of an elliptical beam profile. THz transmission-mode CW imaging of a cross-section of premolar tooth sample with dentine and enamel was conducted at 840 GHz.