Laser-Induced Damage Mechanism of Thin Films for 193-nm multiple pulses

Laser-induced damage thresholds (LIDTs) of fluoride thin films at 193-nm were estimated by irradiation of 2 laser pulses with different separate time of 0.01 to 1.0 seconds. As the separate time was 0.01 second, the LIDT was reduced to about half of 1 pulse LIDT. The transmittance at 100Hz repetition pulses also decreased remarkably. As a result, it would be concluded that the mechanism of the decrease in LIDT was due to the formation of defects and free-electrons.