摘要
Using spontaneous parametric down conversion,polarization post selection and coincidence counting technique,the polarization Einstein-Podolsky-Rosen(EPR) entangled states are prepared.Experimental studies on the efficiency,contrast and fidelity with different pump laser intensities are performed systematically.The results show that the pump laser intensity distinctly influences the quality of entangled photons,especially the contrast and the fidelity.On the other hand,the pump efficiency of entangled photons is almost invariable,namely the entangled source brightness increases linearly with the increase of pump laser power.
基金
supported by the National Natural Science Foundation of China(No.11174224)
the Natural Science Foundation of Shandong Province(Nos.ZR2013FM001,2013SJGZ10 and ZR2014JL029)
the Science and Technology Development Program of Shandong Province(Nos.2011YD01049 and 2013YD01016)
the Higher School Science and Technology Program of Shandong Province(Nos.J13LJ54 and J13LA52)
