Optics and Photonics Society of Iran

In this paper a new method for intruder detection in border protection application using distributed Bragg fiber sensors is proposed. This method is based on exciting the acoustic modes of Bragg fiber under the influence of intruders' passing in borders. The changes in radial component of displacement vector of acoustic modes cause the thickness of Bragg fiber's claddings to change. As a result the quarter wave stack condition is violated and the light loss in place of intruder's passing is increase. By investigating the resulting trace of Optical Time Domain Reflectometry method in Bragg fiber, it is possible to determine the position of intruder's passing in borders.