Talbot array illuminator for single-shot measurements of laser-induced-damage thresholds of thin-film coatings

A highly efficient Talbot array illuminator for single-shot, laser-induced- damage test measurements of optical thin-film coatings is proposed. With a periodic binary phase grating, a laser beam is transformed into an ensemble of Gaussian-like spots, which are known as the Fresnel image of the gratin g. For this purpose hexagonal phase gratings were fabricated and analyzed. With a peak fluence distribution of similar to 1 order of magnitude, the da mage threshold of thin films can be deduced by use of the data from only a single shot. (C) 2000 Optical Society of America.