| 摘要 |
PROBLEM TO BE SOLVED: To provide a dispersion compensating optical fiber and a transmission system which compensate dispersion in the case of using a transmission fiber having zero dispersion in the wavelength of about 1310 nm in the band of 1550 nm. SOLUTION: The dispersion compensating optical fiber is provided with negative dispersion and zero or a negative dispersion gradient within the wavelength range of 1520 nm to 1565 nm. It its embodiment, the fiber is composed of a central core region 100 and a clad 101, and dispersion gradient within range of the wavelength including in the middle a core mode region 105 having a lower refractive index than that of the clad, a core ring region 102 having a refractive index between that of the central core region and that of the clad and a second core mode region 103 having a lower refractive index than that of the clad exists between zero and -1.2 ps/nm<2> -km. The dispersion compensating fiber can be combined to a fiber amplifier in order to form a compensator for reducing an additional loss by it. In an embodiment, the dispersion compensating fiber is a distribution fiber amplifier. |
