2. THz cameras

An imager composed of a single pixel is a single-point sensor; when it's composed of several pixels associated in a matrix on a plane, it's a matrix sensor. Similar to a digital camera, a matrix sensor can image a scene more quickly than a single-point detector.

There are two types of terahertz detection: incoherent detectors, which measure only the amplitude or power of the radiation, and coherent detectors, which acquire both the amplitude and phase of the field.

One of the characteristics of a detector is its sensitivity. Sensitivity corresponds to the ratio between current or voltage output signal and incident optical power, and is expressed in V/W or A/W.

The noise generated by the various components of a detector's measurement chain is characterized by the noise spectral...