Laseroptik has equipped one of its ion beam sputtering (IBS) machines in a special cleanroom environment in order to produce low loss super mirrors with a very high reflectivity. Super mirrors are used for ring laser gyroscopes and need to have scattering losses at 633nm below 10ppm, which can be achieved by IBS.
The total back scattering (TSb) of such a mirror taken from Laseroptik's current production has been measured at the Fraunhofer Institute for Applied Optics and Precision Engineering in Jena and achieved a value of 1.1ppm. At a typical absorption and rest transmission of less than 15ppm, this equals a reflectivity of at least 99,998 per cent and gets very close to the perfect laser mirror.
Apart from low loss mirrors, IBS is also applied for complex filter designs, GDD-optimised fs-mirrors or thin-film polarisers with high extinction ratio requirements.