Automatic measurement device of laser-induced damage threshold and its experiment

A set of 1 064 nm and 532 nm automatic measurement device of laser-induced damage threshold (LIDT) of dual-wavelength optical elements was designed and constructed for automatic detection of LIDT of optical elements film. The device was mainly composed of pulsed laser light source, beam parameter diagnosis component, damage online diagnosis component, scanning motion platform for parts to be tested and control system. The whole measuring device and measurement process were automatically controlled by the computer integrated measuring software based on Labview, which could realize the automatic measurement of damage threshold in the range of energy density from 0.1 J/cm²～100 J/cm², and the device was also used to measure the 1 064 nm antireflection film and aluminum reflection film samples. The results show that the damage thresholds are 27.09 J/cm² and 3.21 J/cm², with a relative uncertainty of 3.91% and 5.61%, respectively.