Patent ID: 9249046
Filing Date: 2016-02-02
CPC Classification: C03B

Claim Text:
1. A method for determining a refractive index profile correction for use in making a graded-index multimode fiber through inside deposition, comprising: (a) providing a target refractive index profile for the graded-index multimode fiber; (b) performing an inside deposition within a tube, the tube having a length and a diameter, the inside deposition using reactive gases and a burner, the inside deposition using a fixed volume flow for the reactive gases and a first burner speed for the burner to deposit a plurality of layers in the tube; (c) collapsing the tube to make a preform; (d) measuring a refractive index profile of the preform; (e) comparing the measured refractive index profile to the target refractive index profile and calculating correction values; (f) converting the correction values to a corrected burner speed for a plurality of layers at least at one position along the length of the tube; (g) making a preform according to steps (b) and (c) with inside deposition using the fixed volume flow and substituting the corrected burner speed from step (f) for the first burner speed of step (b); and (h) repeating steps (d)-(g) until a measured refractive index profile that substantially matches the target refractive index profile is obtained, and the corrected burner speed of step (f) results in a changed thickness of each deposited layer, wherein the sum of all the individual layer thicknesses is constant such that the measured refractive index profile substantially matches the target refractive index profile over the entire length of the preform.