Polyimide optical waveguides and method for the preparation thereof

1. An optical waveguide comprising:

a) a support layer;

b) a core layer including a cross-linked polymeric material obtained by UV irradiation of a polyamide having repeating units of formula (I)

wherein R 1 , R 2 , and R 3 independently represent hydrogen or a (C 1 -C 6 )-alkyl group,

R 4 , R 5 , R 6 , R 7 , R 8 and R 9 independently represent hydrogen, a (C 1 -C 6 )-alkyl group, a (C 1 -C 6 )alkenyl or an aryl group;

X is selected from a covalent bond; a (—CH 2 —) y group, wherein y is an integer from 1 to 10; O; S; NR, wherein R is (C 1 -C 4 )alkyl,

x is 0-5,

m is 1-10, and

n is an integer having an average value of from 5 to 50,000, and the deuterated derivatives thereof.

2. The optical waveguide according to claim 1 , wherein R 1 , R 2 , R 3 and R 4 independently represent hydrogen or a (C 1 -C 3 )alkyl group.

3. The optical waveguide according to claim 1 , wherein said support has a refractive index lower than that of said cross-linked polymeric material.

4. The optical waveguide according to claim 1 , wherein said support layer is a glass layer.

5. The optical waveguide according to claim 1 , further comprising a cladding layer disposed over said core layer on the opposite side of that of the support layer.

6. A method for producing an optical waveguide comprising the steps of

a) spin-coating a polyimide of general formula (I)

wherein R 1 , R 2 , and R 3 independently represent hydrogen or a (C 1 -C 6 )alkyl group,

R 4 , R 5 , R 6 , R 7 , R 8 and R 9 independently represent hydrogen, a (C 1 -C 6 )alkyl group, a (C 1 -C 6 )alkenyl or an aryl group;

X is selected from a covalent bond; a (—CH—) y group, wherein y is an integer from 1 to 10; O; S; NR, wherein R is (C 1 -C 4 )alkyl,

x is 0-5,

m is 1-10, and

n is an integer having an average value of from 5 to 50,000, and the deuterated derivatives thereof,

on a substrate layer to obtain a film of the polyamide of formula (I); and

b) irradiating the film with UV radiation according to a selected pattern.

7. The method according to claim 6 , further comprising the step of spin-coating a cladding layer over the core layer.