  Short-wavelength repulsive potentials for quantum gases allow to realize new
systems and to study new phenomena. Here we report the realization of repulsive
optical potentials for dysprosium atoms in the blue region of the spectrum, at
wavelengths close to 400 nm. We employ a spectrallyfiltered diode laser system
to measure both scalar and tensorial components of the polarizability of
dysprosium, which we find in good agreement with the theoretical predictions.
We demonstrate the implementation of potential strengths appropriate to
manipulate Bose-Einstein condensates, with scattering-limited lifetimes
exceeding one second. This type of optical potentials opens interesting
directions for the study of dipolar superfluids and supersolids.
