MrSeb writes: "It seems like every time I set foot in an airport, there is some new machine I need to stand in, walk through, or put my shoes on. The argument can be made that much of this is security theater — an effort to just make things look safe. However, if a new kind of laser-based molecular scanner lives up to its promise and finds its way into airports as planned, it could actually make a difference. A company called Genia Photonics has developed a programmable picosecond laser that is capable of spotting trace amounts of a variety of substances. Genia claims that the system can detect explosives, chemical agents, and hazardous biological substances at up to 50 meters. This device relies on classic spectroscopy; just a very advanced form of it. In the case of Genia’s scanner, it is using far-infrared radiation in the terahertz band. This is why the US Department of Homeland Security is so keen on getting it into airports. Understandably, some are calling foul on the possible privacy concerns, but this technology is halfway to a Star Trek tricorder."