| 摘要 |
PROBLEM TO BE SOLVED: To improve accuracy of phase compensation in a light transmission and reception system.SOLUTION: A light receiving device 2 receives signal light obtained by overlapping a pilot tone with a wavelength different from a main signal on the main signal, detects phase variation from the pilot tone, and estimates the varied phase. The light receiving device 2 compensates for the phase variation at a position of the main signal overlapped on a position of the phase variation of the pilot tone while slightly adjusting time difference between the main signal and the pilot tone according to wavelength dispersion. Therefore, the light receiving device 2 has such a constitution for coupling N-stages of sets of wavelength dispersion compensating parts 241 and phase noise compensating parts 242. The wavelength dispersion compensating part 241 allocates a dispersion compensating amount in each stage to satisfy a total of dispersion amounts accompanied with the wavelength dispersion, so as to compensate for displacement corresponding to the dispersion compensating amount. Also, the phase noise compensating part 242 extracts the pilot tone, estimates an amount of the varied phase, applies the phase compensating amount to the main signal, and compensates for the phase variation. |
