| 摘要 |
PURPOSE:To substantially obviate generation of polarization dispersion by coiling a dispersion compensating optical fiber in a twisted state. CONSTITUTION:The dispersion compensating optical fiber 3 is coiled in the twisted state, by which a dispersion compensating optical fiber coil 6 is formed. A bending stress acts correspondingly on the dispersion compensating optical fiber 3 and the double refraction arises at the time of coiling the dispersion compensating optical fiber 3 but the dispersion compensating optical fiber 3 is coiled in the twisted state and, therefore, the axial direction of the polarization component generated by the double refraction and the magnitude of the polarization component are dispersed by the twisting. The direction of the polarization component axis and the magnitude of the polarization component are thereby uniformly distributed in the longitudinal direction of the dispersion compensating optical fiber 3, by which the polarization dispersion of the dispersion compensating optical fiber coil 6 is made nearly zero and the polarization dispersion of the dispersion compensator 4 is made nearly zero as well. |
