Adaptive optics (AO) is a critical part of the beam control system for a tactical laser weapon. As the high energy laser (HEL) propagates through the air to the target, atmospheric turbulence degrades the quality of the beam and reduces its effectiveness. Adaptive optics senses these atmospheric disturbances and pre-compensates the outgoing HEL beam to restore its mission performance capability. For the past several years, Northrop Grumman Aerospace Systems has been developing AO systems specifically for tactical laser weapons using an experimental testbed.
Consisting of a wavefront sensor, a deformable mirror, and a control processor, the testbed AO system seeks to correct for turbulence induced disturbances in a low-power laser beam transmitted from another building some distance away. This testbed allows the Northrop Grumman Aerospace Systems beam control team to evaluate various sensor configurations as well as processing and control algorithms and architectures. The compensated beam puts more than eight times the peak intensity on the target than an uncompensated beam. This is an extremely cost effective way to increase the energy delivered to the target for a tactical laser weapon.