Bell state preparation using pulsed non-degenerate two-photon entanglement

Summary form only given. In femtosecond pulse pumped single photon downconversion (SPDC), polarization Bell states have been realized only after post-selections of the two-photon amplitudes are made: especially, spectral post-selection by using narrow-band filters. Instead of the spectral post-selection, one can use a thin nonlinear crystal. However, both methods reduce the available flux of the entangled photon pair significantly. In this paper, we report a Bell state preparation experiment in which we effectively eliminate any post-selection in femtosecond pulse pumped SPDC for the first time.