Abstract

A great deal of research has been carried out over the years with the help of entangled-photon states. Studies range from the examination of quantum paradoxes to practical applications in optical measurements and quantum information. A standard source of entangled photons consists of a nonlinear crystal without a center of symmetry pumped by a highly coherent laser This combination provides a medium for the generation of photon pairs that can be entangled in any number of variables: time, frequency, direction of propagation, and polarization.

© 2000 IEEE