Image Intensifier

This is a vacuum tube integrating photocathode and phosphor screen. Photoelectrons emitted from the photocathode are accelerated towards the phosphor screen and generate a brighter image compared to the input. First generation tubes (Gen. 1) use an electro-static focusing system between the photocathode and the screen. Second generation tubes (Gen. 2) are built with a MCP to increase the number of electrons. Proximity focusing is used between the photocathode and the MCP as well as between MCP and screen. Higher generation tubes (Gen. 3) use different photocathode materials to obtain higher quantum efficiency.

Interframing Time

During the capture of successive images with CCD or CMOS cameras there is a time gap between two images where it is not defined whether an optical signal contributes to one or the other image. This time is called interframing time. Cameras used for PIV applications should have a short interframing time.

IR

This abbreviation stands for Infrared radiation and describes the non visible part of light with wavelengths between 780nm and 1mm. Related to high-speed cameras and streak cameras the range between 780nm and 1.500nm (NIR) can partly be detected.