The likelihood of lasers appearing on the battlefield was boosted last week when Boeing announced that its Thin Disk Laser system had achieved unexpected levels of power and efficiency. In a recent demonstration for the US Department of Defense, the laser’s output was 30 percent higher than project requirements and had greater beam quality, a result which paves the way toward a practical tactical laser weapon.
As it says on the tin, the Boeing Thin Disk Laser system uses a thin disc laser. Also known as an active mirror laser, this type of solid state laser was first developed in the 1990s. Instead of rods, as is found in most solid-state lasers, the thin disk laser uses a layer of lasing material with a thickness less than the diameter of the beam it emits. This layer acts as both the gain medium or amplifier of the laser and as the mirror that reflects the beam.
Behind this layer is a thick substrate that acts as a heat sink. This draws the heat generated by the lasing layer away quickly, which greatly increases the laser’s power and efficiency. Boeing’s system incorporates a number of these high-powered industrial lasers to generate a single, high-energy beam.
According to Boeing, the latest version of the the laser has an output of more than 30 kW, which is 30 percent more than the Department of Defense's Robust Electric Laser Initiative (RELI) requirements, with a similar increase in efficiency.
"These demonstrations prove the military utility of laser systems," says Michael Rinn, Boeing Directed Energy Systems vice president and program director. "In order to be truly viable as a weapons-class system, a laser must achieve high brightness while simultaneously remaining efficient at higher power. Our team has shown that we have the necessary power, the beam quality, and the efficiency to deliver such a system to the battlefield."