Experiments on Einstein-Podolsky-Rosen-type correlations with pairs of visible photons

We describe an Einstein-Podolsky-Rosen-type situation with photons, and we show that quantum mechanics predicts strong correlations at-a-distance. According to Bell's theorem, such correlations cannot be interpreted with a classical-looking model in the spirit of Einstein's idea. We report on the most recent experiments on this subject, which show an excellent agreement with quantum mechanics and a clear rejection of the theories obeying Bell's inequalities. (author)