.Figure 4. Basic components of an optical fiber sensor
system.
Fiber optic sensors can be classified under three
categories: The sensing location, the operating principle,
and the application.
Based on the sensing location, a fiber optic sensor can be
classified as extrinsic or intrinsic. In an extrinsic fiber optic
sensor (see Figure 5), the fiber is simply used to carry light
to and from an external optical device where the sensing
takes place. In this cases, the fiber just acts as a means of
getting the light to the sensing location