| 摘要 |
PROBLEM TO BE SOLVED: To provide a quantum receiver where the level of an output signal is not biased to either '0' or '1' even when quantization efficiency of two detectors has a deviation. SOLUTION: The optical signal (quantum) receiver 1 of this invention is provided with a signal output device 107 that changes a coding method, where even at a receiver side a PMB 102 is used to apply N-value (4-value) modulation to the interpolation signal, the N-value signal is divided into first and second groups comprising N/2 value signals and a detection signal of two photon detectors (Avalanche Photo Diodes APD1 905 and 2 906) is converted into an output signal, depending on the first group and the second group. As a result, the output signal wherein the deviation due to the optical detectors is cancelled is obtained. |
