The National Institute of Justice, the police's R&D arm, is continuing the development of hand-held equivalents of the military's Active Denial System.

As I report over in New Scientist, one of them uses the same microwaves as the Pentagon's non-lethal pain-ray; the other is based in an infra-red laser which they say achieves the same effect at target, but which can be made smaller and lighter.

The infra-red device is none other than the PHaSR, which we last saw in 2005 being touted as a laser dazzler. The reason for the PHaSR's bulk is now apparent; a dazzler can be the size of a pen, but this has to pack in a lot more power to heat the target, even if it's only the outer 1/64 inch of the skin. According to the Joint Nonlethal Weapons Program's fact sheet on PHaSR:

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*PHaSR achieves the desired degree of protection through the synergistic application of two non-lethal laser wavelengths during the course of protection activities that will deter, prevent, or mitigate an adversary’s effectiveness. The laser light from PHaSR temporarily impairs aggressors by “dazzling” them with one wavelength. The second wavelength causes a repel effect that discourages advancing aggressors. *

The "repel effect" is the same as the "goodbye effect" produced by the Active Denial system, except that it will only be on a small spot (maybe four inches across) rather than your whole body. Earlier tests show that this is enough to be effective. The PHaSR dazzler uses the same chassis as the parallel Portable Efficient Laser Testbed (PELT) project, which was also an infra-red weapon. Ity's not clear if there's any dividing line between PELT and PHaSR two except the name. Oh, and if the PHaSR looks like a prop from a science-fiction film, that's because it is, as one of the developers revealed last year:

*"In some respects the weapon was designed by Hollywood, Garcia says. Kirtland researchers borrowed a prop design from a movie company for the modular weapon case, he adds." *

Sid Heal, formerly a Commander in the Los Angeles Sheriff's Department (and before that a Marine) , has long been an advocate of non-lethal weapons and thinks the new devices might have potential.

"Needless to say, the “market” is so vacant with alternatives that ANYTHING is going to be appealing at this point," Heal told Danger Room. "The field trials are the best way to find out what something can do and how well it can do it. From experience, it will also provide us the TTPs (training, techniques and procedures) that no lab can do. The deputies in the field are every bit as innovative and imaginative as the scientists who developed these things and we’ll find out things that no laboratory tests could ever reveal."

Heal tested the existing Active Denial System but says that it has two major drawbacks, size and price. A cheap, portable version with a range of fifty feet would have plenty of applications.

The infra-red laser option seems to have more potential for being made portable, but also has a significant disadvantage – it is not as good as millimeter waves at penetrating clothing, and works best on bare skin. This might be a problem for a military system, a NIJ spokesman told me that in their line "there is always a little bit of skin to target."

Having built the PhaSR, the military have discontinued development, but are showing an interest in more advanced infra-red lasers of their own.

"There are no test plans for the PHaSR prototype," Connie Rankin, a spokeswoman for the Air Force Research Laboratory told Danger Room. "The future of the project will be dependent on a service lead picking up the technology and results from parallel testing that is occurring."

So what is this parallel testing? They're not giving out much detail...

"The Joint Non-Lethal Weapons Program is conducting limited effectiveness testing of a non-lethal thermal laser device," Nancy Koreen, of the Joint Non-Lethal Weapons Directorate told Danger Room. "This non-field-ready prototype system is leveraging data from previous non-lethal laser efforts such as the PHaSR program. The system utilizes a retina-safe fiber laser that can cause a thermal reflexive repel response, similar in effect to the millimeter waves used by the Active Denial System, but using a very small spot size and short exposure. "

It looks a lot like this recent Navy award to Aculight Corporationfor an infra-red fiber laser - "a transportable, highly flexible, fiber-based high-peak-power optical source capable of operating at eye-safe wavelengths…The rugged, fiber-based nature of the laser enables rapid transition to battlefield deployment" – and mentions non-lethal effects as one of its applications. ((Of course, there are also some much bigger infra-red lasers out there, like the gunship-mounted Advanced Tactical Laser, so maybe someone is thinking of a dual-role weapon with adjustable beam diameter.))

The move to Infra-red also fits with the Directorate's Broad Area Announcementfor FY09 Which calls for research into "thermal laser effects for non-lethal application," asking for different wavelengths and "focus on understanding reversible health effects, pulsing methods, and effectiveness through clothing."

Interestingly, the JNLWD are also looking for an alternative to the frequency used by Active Denial: "Studies of the human effects/effectiveness, similar to the thermal repel effect produced by 95GHz millimeter wave radiation, but at higher millimeter wave frequency waveforms."

So, in spite of the fact that the original truck-mounted Active Denial System has yet to be used, the technology is heading rapidly towards the next big thing. Energy requirements mean that you're unlikely to ever have a laser pistol that can burn a hole through someone, but there's no reason you couldn't have one that will cause them a lot of pain. Whether it's tactically effective – and whether it's likely to be seriously misused – remain to be seen.