An Optical Health Monitor for High Power Lasers

"Research on high energy lasers (HELs) has been taking place in laboratories for several years. As the technology matures, HELs are moving out of the laboratory and into applications such as military weapons, industrial material processing and fusionresearch. HELs make significant demands on the optical components, often subjecting coatings, mirrors and lenses to optical energy near the damage threshold of the element. In less-than-ideal environments, contamination of mirrors and lens elements canquickly cause optical coatings to degrade. For this reason, the need exists for on-going monitoring of the critical elements in a HEL system. Cybernet proposes to develop an automated optical health monitoring system that can alert the laser operator todegraded performance and coordinate predictive maintenance. The system acquires data from a number of standard metrology instruments, storing diagnostic data into a dynamic database. Optical characteristics to monitor include reflectance, transmittance,scatter, photothermal and photomechanical response. Once data from the optical sensors is in the database, software routines based on expert systems will track diagnostic data and alert maintenance personnel when performance decreases, or when opticallyinduced damage is imminent. Commercial applications include industrial material processing (welding, cutting, etc) and fusion research."