In very low-light situations or when a very short exposure time is required, a dual-stage image intensifier may be required. The first stage is the same as a single-stage image intensifier; it has a micro-channel plate that multiplies the electrons emitted by the photocathode. The second stage is often referred to as a booster. This stage does not have a micro-channel plate, it multiplies the incoming photons without the saturation characteristics of a micro-channel plate.
Dual-stage image intensifier with fiber-optic coupling
The figure above shows a schematic representation of a dual-stage image intensifier that is fiber-optically coupled to the image sensor. The first stage is similar to a single-stage image intensifier.