A Golay Cell
, or Golay Detector
is a type of detector mainly used for infrared spectroscopy
. It consists of a small metal cylinder
which is closed by a blackened metal plate at one end and by a flexible metalized diaphragm at the other. The cylinder is filled with xenon
and then sealed. When IR radiation is allowed to fall on the blackened metal plate, it heats the gas which causes it to expand. The resulting increase in pressure deforms the diaphragm separating the two chambers. Light from a lamp is made to fall on the diaphragm which reflects the light to a photocell
. Motion of the diaphragm changes the output of the cell.
Its main advantage is that its useful wavelength range is very wide. The response is mainly linear over the entire working range. It also has a quite good response time of the order of 10ms.
However it still isn't preferred over other detectors since it is expensive and bulky.