The US Defense Advanced Research Projects Agency (DARPA) has awarded a phase II contract to Northrop for further development of its fibre laser technology.

Under the $4.6m phase II contract, Northrop will develop a fibre laser with scaling power to 3kW in a single mode fibre amplifier.

Northrop Grumman Aerospace Systems directed energy systems vice-president Dan Wildt said success in phase II would create a powerful springboard for scaling fibre lasers to weapons-class performance levels.

During phase I, the company demonstrated a near-perfect beam quality with a 1kW single-mode fibre amplifier.

Northrop has also demonstrated extremely low phase noise that is necessary for coherent combination of the laser chains used to scale power to weapons-class levels.

The contract is part of the revolution in fibre lasers (RIFL) programme, which aims to develop the technology to produce a 100kW lethal laser weapon.