GCN LAB IMPRESSIONS

Army developing laser-guided lightning bolts

Engineers at the Army’s Picatinny Arsenal in New Jersey have managed to send lightning bolts down a laser beam. And they didn’t even use The Force (as far as we know).

The idea of firing targeted lightning bolts — in this case, a short 500 billion-watt burst of optical power — has been a staple of science fiction fantasies, but has been out of the reach of anyone in the real world. The Laser-Induced Plasma Channel, LIPC, could change that.

Light travels more slowly in a gas (such as our atmosphere) than in a vacuum, and gets even a little slower when the beam pulses more intensely. If the pulses are intense enough, the power output of the laser beam increases to the point that it ionizes the air surrounding it, turning it into plasma.

This sheath of plasma conducts electricity far better than the surrounding, ionized air. So a high-voltage current can be sent along the path of the laser beam and into the beam’s target. To think that people get paid to think this stuff up.

This can have many applications. Most notably, and I hope the first thing they put this to use for, it could be used to detonate unexploded devices (such as land mines or IEDs) safely from a distance. As long as the target conducts electricity better than the ground it’s sitting on, the current caused by the beam will cause it to detonate pretty reliably.

I know you’re thinking, well, why not use this application of technology to beam power everywhere? Well, a couple of things.

First, it would take a great deal of power to have a laser beam constantly ionize the surrounding air. Second, there would be nothing to stop the ionization from occurring inside a lens, or within the amplification device, so they have to send pulses down the laser beam so the electricity goes where they want it.

So, I think for now we will have to stick to the wireless power technology we have available.

A few things have to be accomplished before this can be ready for operational use in the field. Synchronizing the laser pulse with the high voltage is currently tricky at best. Also, many of the components need to be ruggedized to survive combat conditions.

But hopefully someday soon we will see it in use, saving the lives of many of our soldiers by making bomb disposal safer. You can use your imagination to figure out other potential uses.

About the Author

Greg Crowe is a former GCN staff writer who covered mobile technology.

Reader Comments

Thu, Jul 5, 2012 Pseu_An www

Should I be laughing or crying over this developement?

Thu, Jul 5, 2012 earth

http://www.lightning.ece.ufl.edu/ A dart unspooling a copper wire would make sending the electrical power down the line simple. Finding the land mine to get the bolt close seems to be the difficult problem. For that matter a small amout of C4 tossed over the mine should work.

Tue, Jul 3, 2012 Dave Washington DC

Commercial aircraft are struck on a regular basis and suffer little effect, TopGear demonstarted that lighning has no effect on cars and tanks are virtual faraday cages.... so, except for killing sheep how is this weapon expected to do more than burn research dollars?

Tue, Jul 3, 2012

Electric car batteries cannot safely receive charging power at those rates, so you'd have an exploded car rather than a charged one. Much better for the electric car quick-re"fuel" would be the "Blue Rhino" model, where you exchange a depleted battery module for a charged one. A coupler and mecahnism similar to what garbage trucks now use to pick up the cans automatically could work to make this pretty painless.

Tue, Jul 3, 2012

The Delorean from Back to the Future! I want to see the flux capacitor!

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