  We report on the first results of a search for optical-wavelength photons
mixing with hypothetical hidden-sector paraphotons in the mass range between
10^-5 and 10^-2 electron volts for a mixing parameter greater than 10^-7. This
was a generation-regeneration experiment using the "light shining through a
wall" technique in which regenerated photons are searched for downstream of an
optical barrier that separates it from an upstream generation region. The new
limits presented here are approximately three times more sensitive to this
mixing than the best previous measurement. The present results indicate no
evidence for photon-paraphoton mixing for the range of parameters investigated.
