This paper is concerned with the design of high-sensitive, with noise equivalent power (NEP) less than 10-17 WHz-1/2, detectors and imagers of infrared (including submillimeter) radiation. Excitonic detectors are based on IR-quenching effects for secondary visible radiation of crystal and represent the new generation of IR-detectors, because they use optical (contactless) read-out of information from an IR-sensor. It is possible also to create a matrix version of such devices, which supposes the use of light fiberoptics and corresponding processing methods. As a result of our proposition both the single detectors for use in the radiometers, which determine the temperature difference, and visualizers or TV- photocathodes for IR-band, particularly for its far longwave (submillimeter) region, may be created. As it was supposed, just in submillimeter range the exchange by genetic information is realized. The intra-cell water strongly absorbs the submillimeter radiation, however, the nervous fibers are seen to be the dielectric waveguides in the submillimeter band.