High reflecting mirrors for the wavelength of 514 nm were produced with ion-beam sputtering using different process parameters. The optical characteristics were determined by cavity decay time measurement, laser calorimetry, and total integrated scatter measurements. The results for single layer of SiO2 and Ta2O5 were evaluated with respect to an optimization of the deposition process. Furthermore, coatings were investigated by IR spectroscopy and RBS. Laser induced damage thresholds of coatings were measured with a pulsed Nd:YAG laser. Mirrors produced with optimized parameters show absorption values less than 5 ppm, and the scatter losses are in the range of 6 ppm at 514 nm. Adding the transmission loss of the mirrors, this is in good agreement with the results of the cavity decay time measurement. The damage threshold values and the optical losses are discussed and compared to the results of conventional coatings.