Bob Boyce asked:
Would we be able to make lasers so powerful and lightweight that they could replace guns or bullets for the military?
Harry - The Ministry of Defence made a matchbox-sized infrared laser in mid-1980s. You could just push a button on the top of the matchbox and watch a flame appear on the wall, 5 or 6 feet away. I should say, our lasers are not designed for this!
Helen - So they had a go at it in the ‘80s but it doesn’t seem to be actually being used at the moment. Do we have any reasons why that might be?
Harry - Well they might be but we may not be being told. Remember that most of the aircraft flying in the various conflicts around the world use laser ranging to target bombs and God knows what else – missiles I guess! But always remember with light, it’s going to diffract out eventually so you're going to lose intensity. I would guess that these could be used for short range but not long range.