Generation of Polarization Entangled Photon Pairs in a Planar Waveguide
  In this paper, we analyze spontaneous parametric down conversion in a 2D slant strip type periodically poled planar waveguide and show that such a configuration has efficiencies higher than in the case of bulk crystals with the possibility of ease of collection like in channel waveguides with the additional feature of wavelength tunability. The proposed design should find applications in quantum processing using integrated quantum optics. 
Divya Bharadwaj and K. Thyagarajan
quant-ph physics.optics