| 摘要 |
PROBLEM TO BE SOLVED: To detect time fluctuation of PMD amount in a light transmission path. SOLUTION: Wavelength multiple data signal light λ1, etc., λm, etc., λn, etc., λz including data signal light of two wavelengths λn, λm whose polarization relation is known is transmitted into the light transmission path 10. A part of the wavelength multiple data signal light is taken out of the light transmission path 10 by a light tap 11 and is branched into two light in a light wave branching device 12. Light intensity of data signal light of two wavelengths λn, λm whose polarization relation is known is detected in a path of a light wave branching device 13, optical filters 14, 15, and PDs 16, 17 and a path of a polarizer 18, a light wave branching device 19, optical filters 20, 21, and PDs 22, 23. Consequently, time fluctuation of PMD amount in the light transmission path 10 can be analyzed from the comparison of intensity of two kinds of signal light. |
