| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for executing communication through the use of the quantum correlation of a pair of photons by measuring the density of photons passing through a polarizing filter installed in a position where the length of an optical path from a light source is longer among a pair of polarizing filters. SOLUTION: The device is provided with two pairs of polarizing filters I-I' and II-II', which are placed in the positions of optical lengths la-ld from a light source 4, and detectors A and B. Two beams which have photon density np and in which the individual photons have quantum correlation on a polarization direction are radiated from the light source 4. An optical path is provided in the air or through optical paths 5. A pair of photons having quantum correlation on the polarization direction are emitted from the light source 4. When the polarizing filter II is rotated by θ with respect to the filter I, the density of the photons, which is detected by the detector B, is zero in the case of θ=0 deg. and 90 deg.. In the case of θ=45 deg., photon density becomes np/4. When photon density detected by the detector B with θ as a transmission signal is set to be a reception signal, communication can be executed. |
