Breakthroughs in solid-state technology promise airborne munitions that could defeat missiles by end of the decade

Raytheon believes solid-state laser technology has matured to a point where directed-energy weapons suitable for installation on aircraft could be available by the end of the decade.

The company is competing against TRW and others to demonstrate a 25kW laser in the laboratory as a step toward developing a 100kW weapon-grade laser.

Breakthroughs in the last decade have made solid-state laser weapons viable, says programme manager Chan McKearn. These include high-brightness diode-pumped slab lasers using materials that generate less heat, and architectures producing a high-quality beam that puts more energy on the target.

McKearn says Raytheon is working on solid-state lasers, based on ytterbium (Yb), which generate a quarter of the heat produced by neodimium-based lasers. Its architecture uses high-power Yb:YAG slab lasers to amplify a high-quality, low-power beam produced by a master oscillator. A phase-conjugate mirror removes aberrations caused by the amplifiers, producing a tightly focused beam, he says.

Raytheon has demonstrated a 2.6kW solid-state laser in the laboratory and is competing to build a 25kW device for the US Air Force Research Laboratory (Flight International, 1-7 October).

Bench tests of the 25kW laser are planned for 2004-05. The tests could lead to a 100kW weapon-grade laser being available by the end of the decade, says Michael Booen, vice-president directed-energy weapons at Raytheon Missile Systems.

A likely initial use of directed-energy weapons will be to defend aircraft against missile attack. Although a 25kW laser could be enough to damage the seeker on an infrared-guided missile, a 100kW weapon will be needed to defeat radar-guided missiles at useful ranges, says Booen. Other potential uses include surgical attacks in urban areas. "Directed energy is the future of precision strike," he says.

Early candidates for laser weapons include the Lockheed Martin F-35 Joint Strike Fighter, as well as gunships and unmanned combat air vehicles.

Source: Flight International