ABSTRACT
Explosives and energetic precursor materials are becoming commonly used to purposefully harm people and property. Energetic attacks occur in foreign and domestic sites throughout the world. Increasingly, the Department of Defense, coalition military, and security forces are seeking out means to detect and identify explosive hazards before the detonation event occurs, preventing warghters and innocent bystanders from being impacted. Foreign and national governments are pouring funds into industry-, academic-, and government-sponsored research initiatives to develop sensitive and accurate systems for the detection of many classes of hazardous materials. Of the many hazards commonly encountered by warghters, energetics in the form of improvised explosive devices (IEDs) and homemade explosives (HMEs) remain the primary threat to military and civilian personnel. Unfortunately, the energetic materials used to construct these devices can be extremely difcult to detect. This is in large part due to the extensive variety of materials that can be used as explosives or explosive precursors. Therefore, to answer this need, various hazard detection technologies have emerged. For example, ion mobility spectrometry (IMS)1,2 has been employed as an explosive screening technology in most airports since September 11, 2001, and the technology has been adopted for military use in the portable Joint Chemical Agent Detector (JCAD) for the detection of chemical warfare agents and toxic industrial chemicals. The development of specic polymers (e.g., amplied uorescent polymers) for detection of explosives has been successful for a handful of materials,3-5 including 2,4,6-trinitrotoluene (TNT), resulting in commercialization by FLIR®,6 and various colorimetric kits,7 based on chemical reactions that produce colored unambiguous products when exposed to a specic class of analyte, are currently being used by law enforcement and the military. Although these analysis methods have proven effective for certain classes of
1.1 Introduction ......................................................................................................1 1.2 The Challenge ...................................................................................................2 1.3 A Solution: Laser-Based Techniques ................................................................4 References ..................................................................................................................6
