A. Popescu, D. Savastru, S. Miclos, V. Braic, A. Kiss, Super-Gaussian TiO2 laser mirror made by RF-sputtering of pure titanium target, J. Optoelectron. Adv. Mater., 12/12 (2010) 2462 - 2466.

Title: Super-Gaussian TiO2 laser mirror made by RF-sputtering of pure titanium target

Abstract: The aim of this report is the elaboration of TiO(2) thin film coatings with Super-Gaussian reflectivity profile designed to be used as mirror in laser unstable resonators. RE reactive sputtering of pure titanium target was selected as technological method. The gas flow and Ar to O(2) ratio of gas mixture optimization were set as result of optical transmission spectra measurements. Secondary collisions that take place behind the selected stainless steel mask give the possibility to obtain the required reflectivity profile. The central reflectivity of 29 %, the waist of 1.42 mm and the super Gaussian order of 3.5 were obtained. The fitting method and procedure is developed.

Key words: Lasers; Grade-index films; Variable-reflectivity mirror; RF sputtering; TiO(2) films