| 摘要 |
PROBLEM TO BE SOLVED: To increase the conversion probability of a signal photon and an idler photon to a photon pair, and to increase conversion efficiency at an optical communication waveband. SOLUTION: Each optical pulse cross-polarized to each other at the frequencies FP1 and FP2 of the optical communication waveband is emitted from laser beam sources 1 and 2, respectively at the same time, and is transmitted in an optical fiber 4. Two photons having optical frequencies FS and FI are generated from one photon in each optical pulse in a 4-photon mixing process during transmission. The photons of the FS and FI are separated by an optical demultiplexing means 5, transmitted through narrow band filters 6 and 7, thereby a pair of photons having a quantum correlation is obtained at the same time. The values of the optical frequencies FP1 and FP2 are set to be FS-F0=F 0-FI and FP1-F0=F0-FP2, and |FS-F0|<<|FP1-F0| to the frequency F0 corresponding to the zero dispersion light wavelength of the optical fiber 4. |
