Abstract
Output couplers for TEA CO2 lasers were made from Ge substrate coated with dielectric layers of ZnS, Ge and Y2O3 using physical evaporation technique (PVD). The laser-induced damage thresholds (LIDTs) of manufactured mirrors have been investigated using an experimental setup, based on TEA CO2 laser. The effect of preparation conditions, such as grinding, polishing and cleaning, is shown. The maximum value of LIDT about 8 J/cm2 was achieved using a fine grinding with loose abrasive grade 3 µm, then polishing with alumina powder grade 0.3 µm and finally hot cleaning with ultrasonic waves.
Keywords:
Laser-induced damage thresholds; optical materials; coupler mirrors; CO2 laser