Laser induced damage in optical glasses using nanosecond pulses at 1030 nm

摘要

The “Bivoj” 10 J, 10 ns, 10 Hz, Yb:YAG (1030 nm) diode-pumped solid state laser (DPSSL) at the HiLASE Centre wasused to investigate the laser-induced damage of optical glasses with different refractive index (BK7, SF8, FS,LIBA2000). The samples were polished using a combination of methods and cleaned in ultrasonic bath or with ionbeams. Sample surface was characterized using white-light interferometry (WLI) and laser confocal microscopy (LCM).For the laser-induced damage threshold (LIDT), an S-on-1 procedure was selected, the testing taking place in accordancewith the ISO 21254 standard. Due to the high energy per pulse of the “Bivoj” system we were capable of using beamswith more than 500 μm diameter (using a long focusing mirror) and thus, including different surface defect in the LIDTmeasurement. The damage of the glasses was usually observed on the rear side (ballistic damage) due to constructiveinterference, however we manage to see on few samples front damage also. Values above 50 J/cm~2 were common for alltested samples.