| 摘要 |
PROBLEM TO BE SOLVED: To effectively compensate the level difference between the optical submarine transmission lines of long distances at a a low cost by preparing an optical gain equalizer and one or more through fibers in a pressure housing and compensating the gain difference for each wavelength of wavelength multiplex optical signals. SOLUTION: An optical gain equalizer 2 and (n) pieces of through fibers 3 are stored in a pressure housing 1, and the input/output ports are formed at the outside of the housing 1 for the equalizer 2 and the fibers 3. Then (n+1) pieces of optical fibers 7 contained in a submarine cable 5 are spliced to the input/output ports of the equalizer 2 and fibers 3 at each splice point 4. The levels of wavelength multiplex beams are measured in the fibers 7 of the cable 5, and the equalizer 2 is connected to the cable 5 to compensate the level difference between the longest and shortest wavelengths into the optimum value when the level difference is equal to the prescribed value, e.g. 2 to 3 dB. The housing 1 has the same material and shape as those of an ordinary optical submarine repeater, and the equalizer 2 applies a known fiber grating or etalon type. |
