Patent ID: 7099546
Filing Date: 2006-08-29
Classification: B29C,G02B

Abstract:
1. A method of manufacturing a graded index plastic optical fiber wherein the index varies continuously between the center and periphery of the fiber, from at least one polymer P and at least one reactive diluent D1, to allow the refractive index of said fiber to vary, said method comprising the steps of: preparing two compositions with different refractive indices, the difference in refractive index between the two compositions being at least 5×10 active mixing of the two compositions to obtain a continuous variation in the refractive index of the optical fiber; spinning the mixture; curing the mixture to produce a cured optical fiber with a refractive index gradient, said method being characterized in that said polymer P is a terpolymer comprising at least three repeating units P1, P2 and P3 with the following general formulae: in which: X R Y Y Z n equals 0 or 1; A is an ester function or an oxygen or sulfur atom; R B i, j and k correspond to a repeat number of units; the quantity of P3 units in the terpolymer being in the range 2 mole % to 40 mole %, preferably in the range 10% to 20%, and the mole ratio of the P1/P2 units being in the range 0.5 to 5.5, preferably in the range 1 to 2, said terpolymer being transparent, amorphous in nature and having a glass transition temperature (Tg) of more than 25° C.