Characterization of 1 064 nm laser induced damagein ALD optical film

Based on Atomic Layer Deposition (ALD) technology, the single layer films were coated on fused silica and BK7 glass substrate respectively. Using small optical damage test facility, the 1064 nm laser induced damage threshold between ALD films and BK7 substrate was compared. The result shows that the ALD film damage threshold is about 10.3 J/cm2. With the use of Nomarski microscope and Atomic Force Microscope, the morphology of damage site was discussed. The result shows that there are two kinds of damage, the peeling damage on the films and the small pits damage on substrate. The pits damage related to melting and vaporization has the depth between 70 nm and 95 nm. The damage precursors may exist in the boundary surface of ALD films and substrate.