We suggest and demonstrate a scheme for coherent nonlocal compensation of pure phase objects based on two-photon polarization and momentum entangled states. The insertion of a single phase object on one of the beams reduces the purity of the overall detected state and the amount of shared entanglement, whereas the original entanglement can be retrieved by adding a suitable phase object on the other beam. In our setup polarization and momentum entangled states are generated by spontaneous parametric downconversion and then purified using a programmable spatial light modulator, which may be also used to impose arbitrary space-dependent phase functions on the beams.
- hidden-variable theories
- dispersion cancellation
- momentum entangled states
Cialdi, S., Brivio, D., Tesio, E., & Paris, M. G. A. (2011). Nonlocal compensation of pure phase objects with entangled photons. Physical Review A, 84(4), [043817 ]. https://doi.org/10.1103/PhysRevA.84.043817