Fig. 7.

A cancerous tumor inside sample #7 was detected by observation of the THz time-domain waveform obtained at frozen temperature. (a) Optical image, (b) frozen, and (c) room temperature THz images, and (d) a pathological image of a perpendicular section. (e) The THz waveforms from regions indicated by the red arrow in (b) and (c). The second pulse in the THz waveform of (b) indicated by the arrow was reflected by the cancerous tumor inside the sample. (THz: THz radiation, QP: quartz plate).