Here's a photon-photon experiment. The final step consists of a photon-photon interaction to create matter.
http://www.nytimes.com/1997/09/16/science/scientists-use-light-to-create-particles.html
Wikipedia has this interesting statement, "From quantum electrodynamics it can be found that photons cannot couple directly to each other, since they carry no charge, but they can interact through higher-order processes. A photon can, within the bounds of the uncertainty principle, fluctuate into a charged fermionantifermion pair, to either of which the other photon can couple. This fermion pair can be leptons or quarks. Thus, two-photon physics experiments can be used as ways to study the photon structure, or what is "inside" the photon."
http://en.m.wikipedia.org/wiki/Two-photon_physics