Multi-band Terahertz Imaging System Design

Developing visualization devices in far infrared reveals tremendous advantages and focused the research of space agencies, defense and security as well many other private companies oriented to science. The THz wave emitters and receivers are less developed, compared to its neighboring bands (microwave and optical). During the past decade, THz waves have been used to characterize the composition and properties of solid, liquid and gas phase materials to identify their molecular structures. At the base of this development stays the possibility of achieving microstructures from conductive or super-conductive materials able to select by resonant criteria the emerging photons and drive into specialized detection devices. The problem to be solved is the ratio S/N because the energy of a single 1THz photon is 4.1 meV equivalent to a 47K temperature.A group of such highly selective micro-antenna can be grouped into a unit cell - called elementary multi-band detector. The development of resonant structures for frequency selectivity and directivity reasons coupled with the electrical field amplification and detection in low noise quantum transistors. Such an electronic system might be integrated in a modular structure and by multiplicity to create spatial sensors and phased arrays.