A note on 100 kW laser power

The January 2024 Physics Today article titled “The new laser weapons ” (page 32), by Tom Karr and Jim Trebes, reports, “In 2015, General Atomics, the contractor for the distributed-gain laser, achieved 100 kW class power—at the time the highest average power ever achieved in an electrically pumped laser.” In fact, Northrop Grumman and Textron Defense Systems—in 2009 and 2010, respectively—had already each independently demonstrated 100 kW average power from solid-state slab lasers. ¹ I was the vice president of directed-energy weapons at Textron Defense Systems at the time of that work, which took place under the Joint High Power Solid State Laser program, funded by the Defense Department’s High Energy Laser Joint Technology Office under contract with the US Army Space and Missile Defense Command.

The subsequent General Atomics demonstration, funded under the Defense Advanced Research Projects Agency’s High Energy Liquid Laser Area Defense System program, focused on significant weight and volume reductions compared with the earlier demonstrations in order to facilitate integration into airborne platforms.