. 2017 Jul 19;7:5785. doi: 10.1038/s41598-017-06010-8

Table 2.

Comparison of concurrence and S parameter of our source with other sources of polarization-entangled photons.

	Process	Material	C _raw	C _acs.	S _{acc. sub.}
This work	χ⁽³⁾, dual	AlGaAs	0.91 ± 0.01	0.97 ± 0.01	2.78 ± 0.01^a
Lv et al.²¹	χ⁽³⁾, dual	Si	—	—	2.59 ± 0.12^b
Matsuda et al.¹⁹	χ⁽³⁾, single	Si	0.88 ± 0.02	—	—
Olislager et al.¹⁸	χ⁽³⁾, single	Si	—	—	2.37 ± 0.19
Kang et al.³⁷	χ⁽²⁾	AlGaAs	0.92 ± 0.03	0.98 ± 0.01	2.65^b
Orieux et al.¹⁵	χ⁽²⁾	AlGaAs	0.68 ± 0.01	0.75 ± 0.03	2.23 ± 0.01

^aEstimated from reconstructed density matrices as described previously. ^bEstimated from reported visibility of two-photon interference visibilities.