| 摘要 |
PROBLEM TO BE SOLVED: To enable generation of highly pure quantum entangled photon pairs without inducing unnecessary excessive loss and the like using common and simple optical components.SOLUTION: A quantum entangled photon pair generator includes a polarization preserving loop optical path which has both ends connected to a polarization splitting/combining module and has first and second non-linear optical media and a 1/2 wavelength plate for rotating a polarization plane by 90° located between the non-linear optical media. The first non-linear optical medium generates first SHG light from split excitation light propagating anti-clockwise, and generates correlated photon pairs through SPDC conversion of second SHG light propagating clockwise generated by the second non-linear optical medium. The second second-order non-linear optical medium performs a process symmetrical to this. Two correlated photon pairs propagating in opposite directions are combined by the polarization splitting/combining module, after which signal light and idler light are separated and extracted. The loop optical path includes polarization plane manipulation means which manipulates polarization planes of some light components to combine the light as mentioned above. |
