  Many extensions of the Standard Model of particle physics predict a parallel
sector of a new U(1) symmetry, giving rise to hidden photons. These hidden
photons are candidate particles for cold dark matter. They are expected to
kinetically mix with regular photons, which leads to a tiny oscillating
electric-field component accompanying dark matter particles. A conducting
surface can convert such dark matter particles into photons which are emitted
almost perpendicularly to the surface. The corresponding photon frequency
follows from the mass of the hidden photons. In this contribution we present a
preliminary result on a hidden photon search in the visible and near-UV
wavelength range that was done with a large, 14 m2 spherical metallic mirror
and discuss future dark matter searches in the eV and sub-eV range by
application of different detectors for electromagnetic radiation.
