6. Overview of THz radiation detectors

THz radiation detectors are therefore divided into two families, depending on whether they are sensitive to the power or the electric field of the THz beam illuminating them. Measuring the power (or energy) of the beam means that information on the phase of the beam is lost (unless interferometric techniques are used, which are not very widespread in the THz range). In the case of field-sensitive sensors, this phase is preserved, but the rapidity of THz oscillations means that equivalent-time techniques have to be used, requiring repetitive signals (unless "single-shot" techniques are used, which are less sensitive and therefore rarely used).

THz power detectors operate either at cryogenic temperature, giving extraordinary performance at the limit of quantum noise, or at room temperature, with much lower sensitivity compensated by the simpler operation required...