Absorption and laser-induced damage threshold of single-layer HfO₂ film

The absorption of thin films is an important factor that reduces their laser induced damage threshold. The absorption at 1 064 nm and the laser-induced damage threshold at different wavelengths (1 064, 532, 355 nm) of single-layer HfO2 films were measured and analyzed. The results show that laser induced damage threshold is determined by the average value and uniformity of the film’s absorption, which depend on the type and quantity, and the distribution of defects in the film, respectively. The laser damage resistance of the single-layer HfO2 film irradiated at the three wavelengths (1 064, 532, 355 nm) can be deduced qualitatively by the measured absorption at 1 064 nm.