Patent ID: 6628873
Filing Date: 2003-09-30
Classification: G02B

Abstract:
An in-cable monomode optical fiber comprising an optical core surrounded by optical cladding, said optical core presenting an index profile constituted by a stepped central part, surrounded by an intermediate zone of refractive index less than that of said central part, itself surrounded by an annular zone having refractive index less than that of said central part and greater than that of said intermediate zone, said fiber having, for a wavelength of 1550 nm, a chromatic dispersion slope in the range 0 to 0.1 ps/nm2Â·km, said fiber being characterized in that it further presents the following features for a wavelength of 1550 nm:an effective surface area greater than or equal to 60 &mgr;m2, an chromatic dispersion in the range 3 ps/(nmÂ·km) to 14 ps/(nmÂ·km), and a ratio between the effective surface area and 20 the chromatic dispersion slope greater than 900 &mgr;m2Â·nm2Â·km/ps, characterized in that the size S1 defined S1=2&it;â€ƒ&it;&Integral;0r2&it;Î”&it;â€ƒ&it;n&af;(r)&CenterDot;r&CenterDot;&dd;r,where r is the radius and &Dgr;n(r) the index difference between the index at the radius r and the index of said optical cladding, and where r1 is the radius of said central part, is in the range 45Ã—10âˆ’3 &mgr;m2 to 110Ã—10âˆ’3 &mgr;m2 and is preferably in the range 50Ã—10âˆ’3 &mgr;m2 to 110Ã—10âˆ’3 &mgr;m2.