GENERAL REMARKS The heart of every electro-optical device is the radiation detector. It has the function of converting the incident radiation into an electrical signal (voltage or current) which in turn can be amplified, processed, drive displays, and which constitutes a meaningful measure of the incident radiation. The term, detector, usually is applied to a physical device which consists of the radiation transducer itself as well as windows, limiting apertures, possibly electron optics, and cooling units. But the performance of the detector and its capabilities are almost entirely determined by the radiation transducer.
Gerhard O. Sauermann,
"Electro-Optical Systems - Article II The Detection Process - Radiation Transducers," Optical Engineering 12(5), 125182 (1 October 1973). https://doi.org/10.1117/12.7971659