Patent ID: 6453103
Filing Date: 2002-09-17
Classification: H04B

Abstract:
An optical communication system including at least one hybrid transmission unit, said hybrid transmission unit comprising:a dispersion-shifted optical fiber with a length LDSF, having a zero-dispersion wavelength in a 1.55-&mgr;m wavelength band (1530 nm or more but less than 1565 nm) and a dispersion DDSFwith an absolute value of 0.5 ps/nm/km or more with respect to light having a wavelength of 1.58 &mgr;m; and a first high-dispersion optical fiber with a length L1, disposed such that light outputted from said dispersion-shifted optical fiber propagates therethrough, having a dispersion D1 with an absolute value greater than that of the dispersion DDSF of said dispersion-shifted optical fiber with respect to light having a wavelength of 1.58 &mgr;m; said hybrid transmission unit satisfying, with respect to at least signal light having the shortest wavelength in signal light having a bit rate B included in a signal light wavelength band in which wavelength ranges from 1.565 &mgr;m to 1.610 &mgr;m, the following condition: &Dgr;&phgr;XPMÂ·DT&lE;18000 (unit: (ps/nm)Â·(Gb/s)2) DT=(DDSFÂ·LDSF+D1Â·L1)Â·B2 where &Dgr;&phgr;XPM is the total phase shift amount of cross-phase modulation in said signal light having the shortest wavelength under the influence of signal light having the other wavelengths, and DT is the total dispersion in said hybrid transmission unit.