Pump Spectral Bandwidth, Birefringence, and Entanglement in Type-II Parametric Down Conversion
Figure 2
The concurrence as a function of the pump spectral width for different values of the ratio of the crystal transit times (). The dotted curves are the exact, and the solid curves are approximate. The in-set on the top represents the phase-matching functions, exact (the dotted curve) and approximate (the solid curve).