The science fiction ray gun firing a beam of destructive light will become a real world threat this summer. The United States Navy has deployed a prototype Laser Weapon System, or LaWS, aboard the USS Ponce for sea trials that could last about a year. LaWS is the first laser weapon system mounted on a warship by any country.

Once accepted into service between 2017 and 2021, the solid-state LaWS will allow the Navy to effectively neutralize aerial drones, swarm boats and other threats by destroying or crippling them with an intense beam of laser heat that melts internal circuitry and machinery. LaWS is presently not designed to engage incoming missiles, large aircraft, ships or submarines but this capability can be built-in at a later date.

The Navy spent about $40 million over the past six years on research, development and testing LaWS. In operation, the weapon can be aimed accurately at targets by the ship's Phalanx CIWS radar. LaWS has an effective range of one mile or 1.6 kilometers.

LaWS, which is a directed-energy weapon, is finding favor within the US armed forces because its "ammunition" is cheaper than conventional explosive rounds. It laser light beams can be fired for as little as one dollar per shot, while conventional rounds and missiles cost thousands of dollars each.

LaWS uses a solid-state infrared beam that can be tuned to high output to destroy a target or low output to warn or cripple the sensors of a target. Its power output is estimated between 15kW to 50kW for engaging small aircraft and high-speed boats.