Low-light-level TV with II/CCD Coupled Devices: Relative Merits of Different Approaches

Publisher Summary This chapter presents an introduction of low-light-level TV with II/ charge-coupled devices (CCDs). CCDs are nowadays increasingly used for TV image pick-up by virtue of their good detection performance and their excellent reliability. However, the sensitivity of the CCD is not sufficient for use at very low illumination. Because the usefulness of a CCD is limited at low illumination levels, the coupling of an II at the front end of a CCD raises its gain and improves overall sensitivity. The performance will depend on the intensifier chosen and the coupling used. The chapter exclusively considers fiber-optic (FO) coupling because it enables the CCD to collect the photons emitted by the intensifier screen more efficiently. The sensitivity (S 0 ) of an II/CCD system is the ratio between the CCD output and the system's input illumination (measured at the photocathode). From the evaluations of the different II/CCD systems, the following two conclusions can be drawn: (1) generation 2 and 3 intensifiers produce high-performance II/CCD systems, (2) for a number of applications, generation 1 tubes provide a very attractive solution and can produce high-performance II/CCDs when used with demagnification.