Patent ID: 7116877

Claim:
A method of manufacturing a multimode optical fibre suitable for transmission rates equal to or higher than 1 Gigabit/sec, of the method comprising: i) supplying one or more glass forming precursors, and possibly a dopant, to a quartz substrate tube; ii) forming a plasma in the quartz substrate tube for the purpose of bringing about a reaction in a reactive mixture so as to form glass layers, which may or may not be doped, on an interior of the substrate tube; iii) collapsing the substrate tube obtained in ii) into a perform while heating; and iv) drawing an optical fibre from the perform while heating, wherein: the glass layers, which may or may not be doped, are deposited on the interior of the substrate tube in such a manner that separate layers according to ii) are formed in a region having a diameter of 10 μm at most in a center of an optical fibre that is finally drawn, wherein at least one of said separate layers has a surface area of 2 μm 2 at most, wherein a refractive index value in the fibre that is finally drawn increases in a direction of the center thereof.