112303042 劉芊妘
CCD is a type of detector for optical astronomy invented in 1970s. It is a
charge coupled device with high quantum efficiency. Its features include
outputting linear response and digital data, which makes CCD a convenient
device in comparison to previous astronomical devices, for instance, the
photographic plate invented back from mid-19th. As for the phenomenon of
how CCD detect photon, the course introduced a method called photoelectric
effect, where irradiating light will be beamed on a piece of metal. Once the
light is detected by a CCD, a photon comes in afterwards. An electron-hole
pair is created inside the CCD once a photon reaches enough energy. CCD
will then count the number of electrons, using that quantity scientists received,
they'll be able to learn the brightness of the target object. CCD possesses
various benefits, not only does it provides high quantum efficiency, but also
the high sensitivity towards wide range of wavelengths.