Probabilistic generation of entanglement in optical cavities
  We propose to produce entanglement by measuring the transmission of an optical cavity. Conditioned on the detection of a reflected photon, pairs of atoms in the cavity are prepared in maximally entangled states. The success probability depends on the cavity parameters, but high quality entangled states may be produced with a high probability even for cavities of moderate quality. 
Anders S. Sorensen and Klaus Molmer