Intensifier Gating for Ultra-Short Exposure Times
Apart from the obvious advantages of gain and intensification, the intensifier offers additional possibilities. It can serve as a fast shutter, by use of gating. At a negative cathode voltage, the intensifier is open. It closes at a positive voltage. Switching can be done very quickly and at high repetition rates, resulting in very short exposures (down to nanoseconds), synchronized with a camera that can operate at very high frame rates. Ultrashort exposure will reduce any motion smear to a minimum. The figure below shows a recording sequence of a combustion cycle of a fuel injection engine at 22000 fps, made with a gated intensified high-speed camera.
An image intensifier can also serve as a radiation converter. Images in the part of the spectrum that are invisible to the human eye (for example UV or NIR) can be converted to a different part of the spectrum that can be detected by an image sensor. The spectral sensitivity of the image intensifier is determined by the type of photocathode that is chosen.
