R-on-1 automatic mapping: A new tool for laser damage testing
- LETI-CEA-DOPT-Couches Minces pour l`Optique, Grenoble (France)
Laser damage threshold measurement is statistical in nature. For a commercial qualification or for a user, the threshold determined by the weakest point is a satisfactory characterization. When a new coating is designed, threshold mapping is very useful. It enables the technology to be improved and followed more accurately. Different statistical parameters such as the minimum, maximum, average, and standard deviation of the damage threshold as well as spatial parameters such as the threshold uniformity of the coating can be determined. Therefore, in order to achieve a mapping, all the tested sites should give data. This is the major interest of the R-on-1 test in spite of the fact that the laser damage threshold obtained by this method may be different from the 1-on-1 test (smaller or greater). Moreover, on the damage laser test facility, the beam size is smaller (diameters of a few hundred micrometers) than the characteristic sizes of the components in use (diameters of several centimeters up to one meter). Hence, a laser damage threshold mapping appears very interesting, especially for applications linked to large optical components like the Megajoule project or the National Ignition Facility (N.I.F). On the test bench used, damage detection with a Nomarski microscope and scattered light measurement are almost equivalent. Therefore, it becomes possible to automatically detect on line the first defects induced by YAG irradiation. Scattered light mappings and laser damage threshold mappings can therefore be achieved using a X-Y automatic stage (where the test sample is located). The major difficulties due to the automatic capabilities are shown. These characterizations are illustrated at 355 nm. The numerous experiments performed show different kinds of scattering curves, which are discussed in relation with the damage mechanisms.
- Research Organization:
- International Society for Optical Engineering, Washington, DC (United States)
- OSTI ID:
- 552034
- Report Number(s):
- CONF-9510106-Vol.2714; TRN: 97:005737-0010
- Resource Relation:
- Conference: 27. annual symposium on optical materials for high power lasers, Boulder, CO (United States), 30 Oct - 1 Nov 1995; Other Information: PBD: [1996]; Related Information: Is Part Of Laser-induced damage in optical materials: 1995. Twenty-seventh annual Boulder damage symposium, proceedings; Bennett, H.E.; Guenther, A.H.; Kozlowski, M.R.; Newnam, B.E.; Soileau, M.J. [eds.]; PB: 794 p.
- Country of Publication:
- United States
- Language:
- English
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