Security System Based on Bragg Gratings in an Optical Fiber

The figure schematically illustrates an optoelectronic security system in which binary information on the identity of a person or object is encoded in Bragg gratings in an optical fiber. This is not the first optoelectronic security system based on fiber-optic Bragg gratings, but it is the first in which such gratings constitute the basis of a key or an identification tag.