Variable coupling rotational wand for on-line laser beam sampling

As power levels of industrial lasers increase, effective determination of beam profiles over extended operational regimes becomes problematic, due to dynamic range limitations of available detectors. To address this deficiency, a variable coupling rotating wand was developed for on-line monitoring of output radiation from high average power CO₂ lasers. The concept features real-time beam sampling adjustment, activated by wand rotational speed change. An associated controller provides appropriate speed regulation of the wand motor drive, via a computer generated setpoint. Design parameters thereby ensure optimal sensor operation at all power levels. A safety override prevents sensor damage by terminating laser operation, if wand speed decreases below a safe value.