| 摘要 |
PROBLEM TO BE SOLVED: To simultaneously make the wavelength region of an optical transmission system wider and the transmitting distance of the system longer by arranging one or more selective dispersion compensating means which only compensates the cumulative wavelength dispersion of light wavelength on an optical transmission line. SOLUTION: Fig. 3 shows the arrangement of selective dispersion compensating optical elements and the variation of cumulative wavelength dispersion when three wavelengths λ1, λ2, and λ3 are divided and multiplexed. The element 30 only compensates the cumulative wave dispersion of the wavelength λ1 and the element 32 only compensates the cumulative wavelength dispersion of the wavelength λ2. The element 34 is a selective dispersion compensating optical element which only compensates the cumulative wavelength dispersion of the wavelength λ3. The elements 30, 32, and 34 are dispersedly arranged on an optical transmission line at appropriate intervals for compensating cumulative wavelength dispersion. Optical signals having the wavelengths λ1, λ2, and λ3 are individually compensated for cumulative wavelength dispersion. Therefore, a wide wavelength region can be utilized, because the cumulative wavelength dispersion does not increase beyond a prescribed value at any wavelength. |
