Polymeric Optical Waveguide
An organic polymeric optical waveguide or optical fiber and methods of making same are described herein. The waveguide can be used in an integrated optical waveguide device. The polymer is a homo- or copolymer having an olefinic backbone with a pendant group comprising fluorinated aromatic and aliphatic moieties, and is cross-linkable. Polymers having refractive index over a wide range may be prepared by selecting specific constituents of the pendant group thereby permitting the fabrication of optical waveguide tailored for a particular application.
1 . An optical waveguide comprising a core layer and a first cladding layer, at least one of said core or cladding layers comprising an organic polymer comprising monomer units represented by the structure
where n is an integer equal to 0 to 2, R 1 , R 2 , and R 3 are each independently H, F, or lower alkyl, with the proviso that no more than one of R 1 , R 2 , and R 3 can be F at one time; each m is independently an integer equal to 0 to 4; each R 4 is independently F, Cl, or lower fluoroalkyl; each R 5 is independently H, F, lower alkyl, or lower fluoroalkyl, each R 6 is independently H, F, lower alkyl, or lower fluoroalkyl; X is a bond, an ether oxygen, a carbonyl, or
where R 7 and R 8 are each independently H, F, or fluoroalkyl, with the proviso that if R 7 is H or F then R 8 must be fluoroalkyl; Y is a diradical having the formula
where R 9 and R 10 is independently H, F, or fluoroalkyl, with the proviso that only one of R 9 or R 10 may comprise an alkyl or fluoroalkyl chain of more than two carbons, and with the further proviso that if R 9 is H or F, R 10 is fluoroalkyl; and, Q is H, an unsaturated group suitable for use as a cross-linking site, or a radical having the formula
where each of R 11 is independently F or H, and R 12 is a cross-linkable alkenyl or a protected alkenyl.
2 . The optical waveguide of claim 1 wherein said polymer is a homopolymer.
3 . The optical waveguide of claim 1 wherein said polymer is a copolymer.
4 . The optical waveguide of claim 1 wherein R 1 , R 2 , and R 3 are all H.
5 . The optical waveguide of claim 1 wherein each R 4 is F.
6 . The optical waveguide of claim 1 wherein R 5 and R 6 are F.
7 . The optical waveguide of claim 1 wherein each m=4.
8 . The optical waveguide of claim 1 wherein n=0 or 1.
9 . The optical waveguide of claim 8 wherein n=0.
10 . The optical waveguide of claim 1 wherein X is
where R 7 and R 8 each is independently H, F, or fluoroalkyl, with the proviso that one of R 7 and R 8 can be neither H nor F if the other is either H or F.
11 . The optical waveguide of claim 10 wherein R 7 and R 8 are both perfluoromethyl radicals.
12 . The optical waveguide of claim 1 wherein X is —O—.
13 . The optical waveguide of claim 1 wherein R 9 and R 10 are each independently perfluoromethyl or perfluoroethyl.
14 . The optical waveguide of claim 1 wherein one of R 9 and R 10 is a perfluoromethyl or perfluoroethyl radical, and the other is a radical represented by the structure
where k=0-2, j=0 or 1, h=0 or 1, i=1-20, Z is F or H, a=0-2, and R 13 is a perfluoroalkyl radical of 1-20 carbons, k, i, and a all being integers.
15 . The optical waveguide of claim 14 wherein one of R 9 and R 10 is a perfluoromethyl or perfluoroethyl radical, and the other is selected from the group consisting of
—(CF 2 ) 120 —CF 3 ,
—CH(CF 2 ) 1-20 —CF 3 ,
—CF 2 —CFH—(CF 2 ) 1-20 —CF 3 ,
—CF 2 —CFH—(CF 2 ) 1-20 —CHF 2 ,
—CF 2 —CFH—CF 3 , and
16 . The optical waveguide of claim 1 wherein Q is H.
17 . The optical waveguide of claim 1 wherein Q is an unsaturated group suitable for use as a cross-linking site.
18 . The optical waveguide of claim 1 wherein Q is a radical having the formula
where q is an integer equal to 0 to 4, each of R 11 is F or H, and R 12 is a cross-linkable alkenyl or a protected alkenyl.
19 . The optical waveguide of claim 18 wherein each of R 11 is F.
20 . The optical waveguide of claim 1 further comprising a second cladding layer.
21 . The optical waveguide of claim 20 further comprising a buffer layer.
22 . The optical waveguide of claim 1 wherein both said core layer and said first cladding layer comprise the organic polymer recited in claim 1 .
23 . The optical waveguide of claim 22 wherein said core layer, said first cladding layer, said second cladding layer, and said buffer layer comprise the organic polymer recited in claim 1 , said core layer comprising a species of said organic polymer which exhibits a higher refractive index than that which said cladding layer and that which said buffer layer comprise.
24 . The optical waveguide of claim 1 in the form of an arrayed waveguide grating, a Bragg grating, a coupler, a circulator, a wavelength division multiplexer, a wavelength division demultiplexer, a Y-branch thermo-optic switch, or a switch array.