Optical Fiber Bragg grating based intrusion detection systems for homeland security

This paper describes the use of optical Fiber Bragg grating (FBG) sensors for use in various intrusion detection systems for homeland security. We show that a FBG sensor can be used effectively as an embedded in-ground acoustic sensor, sensitive enough to detect the acoustic emissions associated with walking on a concrete surface. Also, the FBG can be used as an in-ground pressure switch for intrusion detection through temporary flooring materials, such as tiles and wooden laminate. In addition, we verify the use of FBGs as in-fence perimeter breach detectors. Finally, we show how an FBG can be used as a reed switch for use in intrusion detection systems for doors and windows. The combination of the different intrusion detection techniques illustrate the versatility of FBGs in security applications, showing this single technology can be used to form a complete intrusion detection system for homeland security. Furthermore the paper details the progress made towards a real-time in-ground sensor network for advanced security applications.