Sensor sweep

The safety of the military and other security services is paramount - could the laser be on its way to realising the tricorder? It's so easy for the crew of the USS Enterprise. If they want to know what something is made of, all they have to do is aim a tricorder at it and all is revealed. Back in the real world, working out whether you are faced with a bomb or a bag of cement is a lot harder and more dangerous. The conflicts in Iraq and Afghanistan have shown how effective the so-called improvised explosive device (IED) can be. It's easy to make and hard to detect. So, the military and security services are looking to sensing technology to give them tricorders for finding telltale chemicals that indicate whether the barrel on the road is just a barrel or something far more deadly. The problem is being able to detect without getting into range of a bomb and the laser, which turns 50 this month, is fast becoming the technology of choice for what the military call "standoff sensor".