In optical detection, the desired non-linearity is embedded in the photon absorption process itself.
The favored transduction principle employed in this type of sensor has been optical detection.
Infrared light or laser technology may be used for optical detection.
The theory of optical detection in multilayer samples, including both interface motion and the photoelastic effect, is now well-developed.
They are also being developed for optical and near-infrared detection at the Palomar Observatory.
However, the low "indiscretion rate" of modern submarines means that optical detection is now less successful.
Under these conditions photon shot noise dominates the sensitivity and this is fundamental to all the optical detection techniques.
The usual method for increasing the sensitivity of optical detection is to use more optical power.
It is important in electronics, telecommunications, optical detection, and fundamental physics.
In large/small devices, the sample is placed in a heating block, and optical detection is automated.