Active Pointing Control of Pulsed, High-Power Laser Beam After 65-Meter Transport

Abstract

Laser-Assisted Charge Exchange (LACE) requires the position and angle of a high-power laser beam to be stable at the sub-millimeter and sub-milliradian level at a point 65 meters from the laser. Due to the high laser power and improvised nature of the laser transport line, the laser beam suffers from pointing instabilities in the form of drift and pulse-to-pulse jitter. A closed-loop Laser Pointing Control System (LPCS) has been developed in the lab and deployed to the field to control and stabilize both the position and angle of the laser beam. The LPCS relies on feedback between CMOS cameras and beam relay mirrors on kinematic mounts controlled by a PC running custom LabVIEW software. The system has been demonstrated to reduce the standard deviation of beam position to 200 μm and of pointing angle to 300 μrad at the interaction point, corresponding to a reduction of ~2x.