Abstract: The piston error problem in a multi-laser optical system having a plurality of parallel component beams is solved by a control loop that responds to a path length difference signal generated by the interference of two of the component beams to adjust one of a set of adjustable component mirrors to reduce the path length difference.

Abstract: In a deformable mirror having a mirror face plate and a plurality of axially movable piezoelectric actuators for controlling the contour thereof, an improvement is provided by which a pneumatic pre-load assembly is inserted between the face plate and the actuators. The assembly includes a core, having apertures therethrough, with a plurality of mirror surface contour posts passing separately through said apertures and a diaphragm plate which is mounted between the face plate and the core and spaced from such face plate but in contact with such core and one end of the posts. A rear plate is mounted to the other end of such posts and in spaced proximity with the core, which core, together with the diaphragm plate and the rear plate, define a cavity therebetween. The posts are aligned with actuators on the other side of the rear plate. Gas is applied to such cavity to bring the posts and the rear plate into contact with their associated actuators so as to pre-load them.

Abstract: An adaptive optic control system employs a single intracavity deformable mirror having a separately controlled multi-pass region and single-pass region to separately control the output power and wave front, respectively.