Since lasers were first developed over 50 years ago, the defence industry has consistently explored their varied uses. Lasers have since found many applications on the battlefield but laser weapons are still at an experimental stage. SDI explores some emerging uses.

The theory of lasers was first explored by Albert Einstein in his paper ‘On the Quantum Theory of Radiation’ in 1917. The term LASER, or ‘light amplification by stimulated emission of radiation’ was coined by Gordon Gould in 1959, but he was beaten to a patent by Bell Labs in 1960.

Prior to the development of practical lasers, the notion of using lasers or ‘ray guns’ as weapons had been widely explored in science fiction. Accuracy over distance and the ability of lasers to damage a target have remained attractive features to the defence agency and to date they have been widely used in targeting and range-finding. However, laser weapons are only just being tested.

Laser guided weapons date back to the Vietnam War. They work by a designator laser illuminating a target with a laser beam using encrypted pulses so that the ordnance can follow the signal without being misdirected by another beam.

One of the latest incarnations is Raytheon’s newest variant of the Maverick missile, currently undergoing flight tests. The company claims the AGM-65E2/L model offers increased accuracy and reduced collateral damage.

Elbit Systems has also introduced a tiny laser designator that can be mounted on mini- or micro-sized unmanned aerial systems (UAS) in order to assign a target with reduced risk of detection.

Omni Sciences, a University of Michigan spinout, is currently developing novel laser technology which could help protect military helicopters by ‘blinding’ heat-seeking missiles that are aimed at them in mid-flight.

The researchers use inexpensive, off-the-shelf telecommunications fibre-optics to produce sturdy and portable mid-infrared supercontinuum lasers. These lasers emit a signal that could blind shoulder-launched heat-seeking weapons from distances of up to 1.8 miles.

St Andrews University in the UK and Princeton University in the US have both recently announced programmes to develop laser systems that can safely detect hidden IEDs (improvised explosive devices) from a distance.

St Andrew’s solution uses a thin film of low-cost light-emitting plastic polyfluorene to create a laser that reacts with vapours from explosives such as TNT. The laser light dims when the plastic comes into contact with even the tiniest emission of vapour and the sensor can be reset by a blast of nitrogen gas.

Princeton’s system sends out a laser pulse and detects a return pulse from the air itself. Any molecules suspended in the air affect the returning signal and carry a ‘fingerprint’ which enables them to be identified.

Lasers have been considered as a solution to overcome potential future bandwidth bottlenecks in traditional radio-frequency communications systems. This system was trialled by the US Air Force for its transformational satellite communications system one programme, which has since been cancelled. Practical applications would require additional investment in precision tracking, pointing and acquisition capabilities.

Laser energy R&D specialist LaserMotive has developed a demonstration model of an unmanned rotorcraft powered remotely by an eye-safe laser.

The system uses laser power beaming, in which energy is transferred wirelessly over distances using laser light. This means the UAV can be kept aloft almost indefinitely, independent of an on-board power source.

The laser-powered helicopter has flown for nearly two hours in laboratory tests, making it the longest duration laser-powered helicopter flight on record.

Northrop Grumman has developed the maritime laser demonstration (MLD) weapons system for the US Navy. In demonstrations, the system was operated from a fixed platform on dry land and fired a laser beam at a number of stationary targets, including representative small boat sections, across a river.

The laser burned through small boat sections in these tests, conducted in late August and early September 2010. It is designed to be as lethal at longer ranges as other previously demonstrated approaches, while using less laser power.

BAE Systems has also demonstrated a non-lethal laser that aims to deter potential pirate attacks on commercial vessels with a dazzling light that can distract and disorientate targeted individuals.