Integrated circuit sensor consisting of many different pixels detecting the incoming light and creating a digital image.
Semiconductor diode that is designed to be very sensitive as it is used close to the avalanche breakdown. Can be so sensitive that even single photons are detected, and then usually denoted named single photon avalanche diode.
Thermal sensor that detects infrared radiation by measuring the heating of a small detector. Can also be used in an array so that thermal images are generated.