Interference in dielectrics and pseudo-measurements
  Inserting a lossy dielectric into one arm of an interference experiment acts in many ways like a measurement. If two entangled photons are passed through the interferometer, a certain amount of information is gained about which path they took, and the interference pattern in a coincidence count measurement is suppressed. However, by inserting a second dielectric into the other arm of the interferometer, one can restore the interference pattern. Two of these pseudo-measurements can thus cancel each other out. This is somewhat analogous to the proposed quantum eraser experiments. 
Todd A. Brun (Physics, QMW, University of London), Stephen M. Barnett   (Physics, University of Strathclyde)