Patent ID: 7016581

Claim:
A dispersion compensation unit, comprising: a first optical fiber having a negative chromatic dispersion D 1 and a negative dispersion slope S 1 at a wavelength in use; a second optical fiber connected to said first optical fiber, said second optical fiber having a positive chromatic dispersion D 2 and a positive dispersion slope S 2 at the wavelength in use; and a case accommodating both said first and second optical fibers wherein letting L 1 be a length of said first optical fiber and L 2 be a length of said second optical fiber, a ratio R of said entire compensating unit defined by “R=(S 1 L 1 +S 2 L 2 )/(D 1 L 1 +D 2 L 2 )” is set to be greater than a ratio (S 1 /D 1 ) of the dispersion slope S 1 to the chromatic dispersion D 1 of said first optical fiber.