VISION-BASED SYSTEM FOR AUTOMATIC STABILIZATION OF MODE, BEAM STEER, AND OUTPUT POWER OF A HIGH-POWER LASER

As advancements in laser technology result in higher-power devices, in creased thermal loads experienced by resonator optical components gene rate instabilities in the output beam. Consequently, methods for maint aining and optimizing output-beam parameters are necessary for efficie nt long-term operation. This study examines a vision-based feedback co ntrol system which monitors a sampled cross-sectional image of the las er's output, and regulates both cavity mirrors. as well as the excitat ion level, to stabilize beam uniformity, beam steer, and output-power level. The system optimizes the output-power distribution achievable f rom a given laser, while significantly reducing beam steering effects. Direction of beam propagation is restricted to within 60 murad of the desired setpoint, while the output power is stabilized to within 4%. Results clearly document a considerable improvement in laser performan ce through maximization of beam uniformity, minimization of beam steer ing, and stabilization of total output power. As such, an important de gree of consistency and repeatability in output-beam parameters, essen tial to precision laser applications, is easily achieved. Valuable dia gnostic capabilities pertaining to output beam intensity and energy pr ofiles are also incorporated into the control system. These data may b e monitored on-line or stored for subsequent analysis.