Coated photonic crystal fibers
View Patent ↗The present invention relates to coated photonic crystal fibers including a photonic crystal fiber and a protective coating surrounding the photonic crystal fiber. The coating is obtained by curing a resin composition, which may include a urethane (meth)acrylate oligomer. The present invention also relates to a coated photonic crystal fiber including a photonic crystal fiber and a protective coating having a refractive index below 1.45.
1. A coated photonic crystal fiber comprising:
(i) a photonic crystal fiber; and
(ii) a protective coating surrounding said photonic crystal fiber, wherein said protective coating has the following combination of properties
(a) an elongation to break of at least 25%;
(b) a secant modulus below 100 MPa;
(c) an adhesion to glass at 50% RH of at least 0.2 N;
(d) an adhesion to glass at 95% RH of at least 0.02 N; and/or
(e) a water sensitivity of less than 10 wt %.
2. An optical fiber ribbon comprising a plurality of coated photonic crystal fibers according to claim 1 .
3. The coated photonic crystal fiber of claim 1 , wherein said protective coating has an elongation to break of at least 50%.
4. The coated photonic crystal fiber of claim 1 , wherein said protective coating has an elongation to break of at least 100%.
5. The coated photonic crystal fiber of claim 1 , wherein said protective coating has a secant modulus below 50 MPa.
6. The coated photonic crystal fiber of claim 1 , wherein said protective coating has a secant modulus below 2.5 MPa.
7. The coated photonic crystal fiber of claim 1 , wherein said protective coating has an adhesion to glass at 50% RH of at least 0.3 N.
8. The coated photonic crystal fiber of claim 1 , wherein said protective coating has an adhesion at 50% RH of at least 0.5 N.
9. The coated photonic crystal fiber of claim 1 , wherein said protective coating has an adhesion at 95% RH of at least 0.04 N.
10. The coated photonic crystal fiber of claim 1 , wherein said protective coating has an adhesion at 95% RH of at least 0.15 N.
11. The coated photonic crystal fiber of claim 1 , wherein said protective coating has a refractive index below 1.40.
12. The coated photonic crystal fiber of claim 1 , wherein said protective coating has a refractive index below 1.37.
13. The coated photonic crystal fiber of claim 1 , wherein said protective coating is obtained by curing a resin composition.
14. The coated photonic crystal fiber of claim 13 , wherein said curing is effected by ultraviolet radiation.
15. The coated photonic crystal fiber of claim 13 , wherein said curing is effected by electron beam radiation.
16. The coated photonic crystal fiber of claim 13 , wherein said curing is effected by heat.
17. The coated photonic crystal fiber of claim 1 , wherein said protective coating has a glass transition temperature of at most 10° C.
18. The coated photonic crystal fiber of claim 1 , wherein said coated photonic crystal fiber comprises a further coating surrounding said protective coating.
19. The coated photonic crystal fiber of claim 18 , wherein said further coating has a glass transition temperature of at least 40° C.
20. The coated photonic crystal fiber of claim 18 , wherein said further coating has a secant modulus of at least 300 MPa.
21. The coated photonic crystal fiber of claim 18 , wherein said protective coating and/or said further coating is obtained by curing a composition comprising an oligomer having at least one ethylenically unsaturated group.
22. The coated photonic crystal fiber of claim 21 , wherein said oligomer comprises a backbone having ether and/or ester groups.
23. The coated photonic crystal fiber of claim 21 , wherein said oligomer comprises fluorine atoms.
24. The coated photonic crystal fiber of claim 1 , wherein said protective coating is obtained by curing a composition comprising at least one silane coupling agent.
25. The coated photonic crystal fiber of claim 18 , wherein said protective coating and/or said further coating are obtained by curing a composition comprising at least one photoinitiator.