| 摘要 |
PURPOSE:To reduce wavelength dispersion in a transmission wavelength range by interposing a dispersion compensation line which cancels wavelength dispersion generated on an existent line in a transmission wavelength range different from specific wavelength in the middle of the existent line which is so set as to has no dispersion only to the specific wavelength. CONSTITUTION:The wavelength dispersion generated on the existent line 6 of length L(km) is m0L(ps/nm), where m0 is the wavelength dispersion coefficient of the existent line 6 of transmission wavelength (ps/km/n); and the dispersion compensating line 7 made of a single mode fiber which satisfies m0L+ml=0 is interposed to eliminate the wavelength dispersion of the total transmission line, i.e. transmission line between the terminal of the transmitter 6 on the existent line 6 and the terminal of the receiver 5. Here, (m)(ps/km/nm) is the wavelength dispersion coefficient of the dispersion compensating line 7 corresponding to the transmission wavelength and l(km) is the substantial length of the single mode fiber constituting the dispersion compensating line 7. Consequently, even if the wavelength dispersion of the transmission wavelength range occurs on the existent line 6, this dispersion is canceled by the dispersion compensating line 7 and the output side, i.e. receiver 5 is not affected by the wavelength dispersion at all. |
