| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a function of extracting a clock signal for detecting photon arrival, operating with an expected value of the number of generated correlation photon pairs stably maintained to a constant value. <P>SOLUTION: To output a variety of wavelength components, including correlation photon pair wavelength components output from a loop optical path 46, the quantum key distribution system includes an optical circulator 48, an optical low pass filter 54, a first optical branch unit 52, a second optical branch unit 70, a second optical multiplexer 72 and a third optical multiplexer 74. The output light of the second optical multiplexer is transmitted to a recipient A via a first quantum channel, and the output light of the third optical multiplexer is transmitted to a recipient B via a second quantum channel. First and second control signals are generated respectively from the output light of a third optical branch unit 76 and a fourth optical branch unit 78. The clock signal is extracted from an auxiliary idler light component transmitted through the first and second quantum channels. <P>COPYRIGHT: (C)2012,JPO&INPIT |
