Laser weapons

Once upon a time I worked for Dstl, the Defence Science and Technology Laboratory (and prior to that DERA), which is the R&D arm of the UK Ministry of Defence. As such I see a value for science input into the protection and enhancement of our armed forces. While I can’t tell you exactly what I worked on, my optics background may give you an idea. What I did, was in my opinion, important and necessary, but didn’t involve the development of weapons in any way. I’m not sure how I would have felt about working in an area more directly related to hurting people.

One of the things I was allowed to do was to look through a wide range of classified research work, as well as go on various training courses, related to optical techniques and applications. On of the things that I got vaguely interested in was laser weapons (and note I never worked on these), primarily as they often came up in discussions to do with adaptive optics. There are many problems associated with developing laser weapons – stability of sources on deployment platforms (such as moving vehicles), power scaling and then beam stability on propagation through the atmosphere. These are non-trivial problems and a lot of research effort has gone into solving these by, primarily the US military and contractors.

Such a system was demonstrated by the US Office for Naval Research this week, developed by Northrop Grumman, in which a boat engine was destroyed in sea trials. It doesn’t look that impressive, but the technical feat in getting it to work is.

What most interested me about this though is what I learned about laser (or directed energy weapons) during my Dstl reading days, and to some extent before that during my PhD. What I found most interesting is that directed energy weapons which are designed to blind someone are forbidden by the Geneva Convention. However, one is allowed to design systems which can lead to the indirect blinding of someone. So for example you can build a system to destroy binoculars, and if indirectly that leads to the blinding of he observer then that is probably OK. This has always struct me as being wrong, but this also strikes me as odd, as guns to kill, main etc are allowed by the Convention.

The mindset of the military is also interesting here. As a PhD student I worked on a topic called electromagnetically induced transparency (EIT), in which a non-transparent medium can be made transparent by application of a laser beam. This is a cool and counter-intuitive effect using quantum coherence, but the military (apparently) inquired of my supervisor before I started if this could be used to obviate the use of laser goggles. So if I developed a laser weapon to blind someone, I could probably be thwarted by my opponent using laser goggles to block the laser. But could you use EIT to make the goggles transparent to the original light?Thoughts like this make me a bit scared of what the military considers acceptable, particularly as this would break the Geneva Convention. But even in fairly conservative areas like laser physics we still, sometimes, have to think on the ethics of what we are doing and what we are developing.

So for any laser scientists out there, defence work holds many opportunities, but you do need to think about the directions in which your research will lead. It’s not always for the good.