There is also a type of weapon that uses
lasers
peripherally, i.e. not to damage the target directly. The best example is the
Laser Immobilizing Weapon which is being developed by HSV Technologies. IT is actually an evolution of the
Taser weapon; it is designed to
immobilize human targets by hitting them with
high-voltage,
low-current electric pulses designed to
mimic neural signals. These pulses cause the major
skeletal muscles of the target to
tetanize, or contract and freeze. The target is thus immobilized for the duration of the beam striking his or her body.
The laser comes into it because unlike the Taser, this weapon has no wires. It uses twin far-ultraviolet laser beams to ionize two paths of atmosphere between the weapon and the target, and then sends the electrical pulses down one path, allowing them to return up the other to create a circuit. The laser itself is too weak to harm a human, even if aimed at the eyes; however, it will cause oxygen molecules to ionize and flouresce due to its frequency. The ionization allows them to pass current. The surrounding atmosphere acts as an extremely effective insulator, keeping the current within the beam path. The oxygen hit by the UV laser will flouresce green, meaning there will be a weak green glow along the beam path when the weapon is operating.
The device has a range of several hundred feet before the atmosphere absorbs the laser energy without ionizing. If more power is available, the same principle can be used at a longer wavelength (I believe 248 angstroms?) which offers a range of two kilometers or so. This is being utilized to produce a vehicle-mounted anti-vehicle version, which is designed to ionize a path to the target vehicle and then pass an extremely large pulse of around 500 milliseconds designed to destroy the target's electronic controls. So if you're being chased, you want to be in a carbureted car as opposed to one with fuel injection.
This device has apparently been tested, and HSV (the company designing it) is in the process of refining the design to fit into a hand-held version. Phasers on stun, anyone?
Information taken from the company website at www.hsvt.org.