In-line quantitative phase imaging for damage detection and analysis

We investigate quantitative phase imaging as a measurement method for laser damage detection and analysis of laser induced modification of optical materials. Experiments have been conducted with a wavefront sensor based on lateral shearing interferometry technique associated to a high magnification optical microscope. The system has been used for in situ observation of optical thin films and bulk samples irradiated by 500fs pulses. It is shown that the technique realizes high sensitivity, convenient use and can provide quantitative information on the refractive index or surface modification of the samples under test.