Terahertz scanning system

Abstract

A terahertz scanning system (11; 12; 13) is described. The terahertz scanning system (11; 12; 13) comprises a terahertz source (2) for emitting a terahertz pulse signal (3) into a region under inspection (4) and a terahertz detector (5) for receiving a reflected terahertz pulse signal (6) from the region under inspection (4) and providing a corresponding measurement signal (7). The terahertz scanning system (11; 12; 13) also comprises a contact pressure sensor (9) for determining a contact pressure applied to a surface (11) of the region under inspection (4) and a processing system (8). The processing system (8) is configured, in response to receiving first and second measurement signals: to compare a first measurement signal with a second measurement signal or with a reference measurement signal, the first measurement signal obtained at a first time at which a first contact pressure has been applied for a first contact duration, the second measurement signal obtained at a second time at which a second contact pressure has been applied for a second contact duration; to determine a degree of deviation between the first measurement signal and the second measurement signal or the reference measurement signal; and in dependence on the degree of deviation, to identify a state of the region under inspection (4).

Dependencies are inferred from the claim text.