ABSTRACT
Several methods of studying biological tissues with THz radiation are discussed. The specific features of radiation of this frequency range interaction with bio-objects include low scattering (due to the large wavelength), noninvasiveness (due to small photon energy), excitation of phonon modes of polycrystalline organic molecules, and high absorption and dispersion of water, the major component of biological tissues. The intensive development of this field of study became possible with the advent of the THz-time-domain technique. This method has a subpicosecond time resolution, provides direct-phase information, measures the reflection of short pulses from interfaces, and allows for broadband, low-frequency spectroscopy. All of these features may help to better visualize tissue properties and hidden tissue structures.
