Bragg reflection waveguide as a source of wavelength-multiplexed   polarization-entangled photon pairs
  We put forward a new highly efficient source of paired photons entangled in polarization with an ultra-large bandwidth. The photons are generated by means of a conveniently designed spontaneous parametric down-conversion process in a semiconductor type-II Bragg reflection waveguide. The proposed scheme aims at being a key element of an integrated source of polarization-entangled photon pairs highly suitable for its use in a multi-user quantum-key-distribution system. 
Ji\v{r}\'i Svozil\'ik, Martin Hendrych, Juan P. Torres
quant-ph physics.optics