The terahertz (THz) band of the electromagnetic spectrum extends from the upper edge of microwaves to near infrared, within 1011 to 1013 Hz. This spectrum includes electromagnetic waves whose corresponding wavelengths are just right to allow penetration through clothing, fog, and skin. Other wavelengths (also within the above spectrum) match significant absorption resonances of large organic molecules. At the same time, THz radiation is non-ionizing and its associated radiation power is low, hence it is considered safe for the surveyed public. The combination of penetrating yet safe radiation can be used for a wide variety of new and extraordinary applications:
- Medical imaging - The radiation can penetrate a short distance beneath the skin and thus has the potential to spot tumors.
- Security/surveillance imaging - The radiation passes through most types of clothing, allowing "intimate" body search at a distance.
- Real-time spectroscopy - Molecules can be identified by the way they reflect short pulses of THz radiation.
The upper THz region (>0.5 THz) is known as "the terahertz gap" since currently no solid state devices and circuits for this region are available, indicating the breakthrough potential of the proposed project. At the lower THz region (0.1-0.3 THz) there is a lack of suitable electronic devices and circuits in silicon technology, covering all the necessary components of a passive and active (RADAR) imaging system.
Two projects are currently being drawn up with the main aim of "filling the THz gap" using groundbreaking silicon-based technology. The upper THz region (~1 THz) is addressed by a breakthrough in Passive Focal Plane (FPA) array technology made available using novel CMOS-SOI-MEMS thermal sensors. The lower THz region (0.1-0.3 THz) is addressed by synergetic fusion of innovative passive and active FPA systems based on nano-scale Si/SiGe technology.