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The Golay cell is a type of opto-acoustic detector mainly used for
The Golay cell is a type of opto-acoustic detector mainly used for infrared spectroscopy
Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or function ...
. It consists of a gas-filled enclosure with an infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
absorbing material and a flexible diaphragm or membrane. When infrared radiation is absorbed, it heats the gas, causing it to expand. The resulting increase in pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ...
deforms the membrane. Light reflected off the membrane is detected by a photodiode, and motion of the membrane produces a change in the signal on the photodiode. The concept was originally described in 1947 by Marcel J. E. Golay, after whom it came to be named.
The Golay cell has high sensitivity and a flat response over a very broad range of frequencies. The response time is modest, of order 10 ms. The detector performance is degraded in the presence of mechanical vibrations.
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