Time-domain transillumination of biological tissues with terahertz pulses

We present time-domain transmission imaging of an opaque structure in pork-fat tissue obtained with a terahertz (THz) field sampling technique. Compared with imaging with near-infrared pulses, the terahertz sampling technique shows significantly enhanced contrast, as a result of low scattering. For enhanced spatial resolution, we show mid-infrared THz imaging of onion cells. Water absorption of THz pulse in muscle tissues is discussed. (C) 2000 Optical Society of America OCIS codes: 110.3080, 170.6920, 290.7050, 290.5820, 300.6270.