A new on-line beam analyzing system based on pyroelectrical detectors for simultaneously detection of the CO2-laser beam characteristics is described. In addition to simultaneously recordings of fluctuations in power, state of polarization and energy distribution, the system has a unique capability of on-line detection of the caustic parameters including a beam quality number describing the focusability of the beam.
The system is invented for investigation of the changes in the laser performance, when light back scattering occurs during material processing with lasers. For this purpose the beam analyzing system is placed in the beam path of a 1.5 kW industrial laser used for welding and cutting. Results from the investigations are presented and discussed.