US military developing plasma laser gun
The US military is trying to make a non-lethal laser plasma gun as loud as the roar of a fighter jet iStock

The US military is developing a new non-lethal weapon that uses an incredibly loud sound to startle an enemy into retreating.

The Laser-Induced Plasma Effect (LIPE) weapon was designed by the Joint Non-Lethal Weapons Program (JNLWP), which is part of the US Department of Defense. It works by making use of plasma, a type of matter that isn't a liquid, solid or gas.

In the plasma stage, high doses of energy have pulled electrons from their atomic nuclei, creating ions, and this produces a type of matter that has both electrical and magnetic properties and can take on the form of light.

The idea is for the LIPE weapon's lasers to fire directed high energy in extremely short bursts that last for only a nanosecond (a billionth of a second). The energy creates a blue ball of plasma and further blasts of energy from the lasers manipulate the ball to make a super loud, 130-decibel sound that sounds like a fighter jet has come out of nowhere next to the target.

"We've demonstrated it in the lab at very short ranges. But we haven't been able to demonstrate it at even 100 metres. That's... the next step," David Law, technology division chief at JNLWP told Defense One.

The total cost of the research will be about $3m (£1.93m) and involves Physical Optics Corp working on producing the lighting effects, while electro-optics firm GEOST is working to create the sound.

JNLWP has previously carried out other projects looking to develop a plasma-based weapon, such as the Pulsed Energy Projectile in 2002, which aimed to create a weapon with a sound effect that was powerful enough to completely knock people off their feet.

Slated to be released in 2007, all news and information about the project vanished completely. Meanwhile, in 2004 the US Navy began testing out plasma to deflect missiles, known as Plasma Point Defense, but that too has yet to be realised and there is no further news.

"Current plasmas maybe achieve 90 to 100dB... we are trying to get to be around 130dB or a little more," said Law, likening the difference in sound to the difference between a lawn mower and a fighter jet.

"Every dB is a factor of 10 times the loudness... We've been working on this in bits and pieces since 2009, but it really has been just over the past couple years that the laser technology has matured enough to be able to potentially get this kind of sound out."

JNLWP plans to test out prototypes of the LIPE gun over the next few months and will evaluate the results of the entire programme in May 2016.