Back to results
US 6,474,105 B1Granted
Modulating a diameter-increasing step of a fiber preform with no modulation prior to a predetermined diameter
AssigneeAlcatel Cable
InventorsBenoît Gouez, Pierre Ripoche
Life of this patent
Estimating the term…
Abstract
The method includes axially modulating at least one plasma build-up pass in order to improve the opto-geometrical properties of the preform. The modulation preferably takes place during the final passes of plasma build-up and takes place by modulating the build-up grain flow rate. The diameter of the preform is evaluated (6), and a build-up control device (8) regulates grain flow rate (11, 5) in application of the above method.
Claims9
A method of obtaining an optical fiber preform by employing build-up, the method comprising the following steps:
- (a) providing an elongated preform in an enclosure;
- (b) successively forming layers of preform material on said preform by depositing said preform material along a length of said preform with a preform material depositing means in a plurality of discrete, successive build-up passes to increase a diameter of said preform;
- (c) monitoring the diameter of said preform to detect variation in the diameter along the length of said preform;
- and
- (d) modulating at least one build-up parameter of said preform material depositing means along the length of said preform based on said monitoring step for at least one of said build-up passes, wherein said modulating step is initiated when said preform reaches a predetermined diameter irrespective of whether the monitoring step detects variations in the diameter along the length of said preform during formation of said layers when the diameter is less than said predetermined diameter;
- wherein said modulating step occurs during at least one of said build-up passes which is preformed when the diameter of said preformed is above said predetermined diameter.
3 more elements
Dependencies are inferred from the claim text.