Determinant of laser-induced-damage of thin film by the scan of transmission and reflectance

The transmission and reflectance of optical thin film were tested using the scan facility at 1.06m m. Scan lines were drawn from the experimental data. The scan lines of two kinds of thin film were analyzed. By using the method, the first kind of damage which is obvious by microscope could be detected accurately, some of the second kind of damage which is not obvious by microscope could also be found. The comparison between scan results and microscope observation shows that the scan method is of higher sensitivity. The reason why the scan method is more sensitive than microscope was discussed. As it is easy to establish the facility, it can be used for online test.