Planar optical waveguide assembly and method of preparing same
View Patent ↗A method of preparing a planar optical waveguide assembly, comprising the steps of (i) applying a curable polymer composition to a surface of a substrate to form a polymer film; (ii) curing the polymer film to form a lower clad layer; (iii) applying a silicone composition to the lower clad layer to form a silicone film; (iv) exposing at least one selected region of the silicone film to radiation having a wavelength of from 150 to 800 nm to produce a partially exposed film having at least one exposed region and at least one non-exposed region; (v) removing the non-exposed region of the partially exposed film with a developing solvent to form a patterned film; and (vi) heating the patterned film for an amount of time sufficient to form at least one silicone core having a refractive index of from 1.3 to 1.7 at 23° C. for light having a wavelength of 589 nm; wherein the lower clad layer has a refractive index less than the refractive index of the silicone core. A planar optical waveguide assembly prepared according to the method of the invention.
1. A method of preparing a planar optical waveguide assembly, comprising the steps of:
(i) applying a curable polymer composition to a surface of a substrate to form a polymer film;
(ii) curing the polymer film to form a lower clad layer;
(iii) applying a silicone composition to the lower clad layer to form a silicone film, wherein the silicone composition comprises:
(A) an organopolysiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule,
(B) an organosilicon compound containing an average of at least two silicon-bonded hydrogen atoms per molecule in a concentration sufficient to cure the composition, and
(C) a catalytic amount of a photoactivated hydrosilylation catalyst;
(iv) exposing at least one selected region of the silicone film to radiation having a wavelength of from 150 to 800 nm to produce a partially exposed film having at least one exposed region and at least one non-exposed region;
(v) removing the non-exposed region of the partially exposed film with a developing solvent to form a patterned film; and
(vi) heating the patterned film for an amount of time sufficient to form at least one silicone core having a refractive index of from 1.3 to 1.7 at 23° C. for light having a wavelength of 589 nm; wherein the lower clad layer has a refractive index less than the refractive index of the silicone core.
2. The method according to claim 1 , wherein the curable polymer composition is a curable silicone composition.
3. The method according to claim 2 , wherein the curable silicone composition is the silicone composition in step (iii).
4. The method according to claim 1 , wherein the substrate is silicon or silicon dioxide.
5. The method according to claim 1 , wherein the lower clad layer has a thickness of from 5 to 200 μm.
6. The method according to claim 1 , wherein the organopolysiloxane is an organopolysiloxane resin.
7. The method according to claim 6 , wherein the organopolysiloxane resin consists essentially of R 2 3 SiO 1/2 units and R 1 SiO 3/2 units, wherein the mole ratio of R 2 3 SiO 1/2 units to R 1 SiO 3/2 units is from 0.05 to 1.0, each R 1 is independently selected from hydrocarbyl, deuterium-substituted hydrocarbyl, and halogen-substituted hydrocarbyl, all free of aliphatic unsaturation, and R 2 is R 1 or alkenyl.
8. The method according to claim 7 , wherein the organopolysiloxane resin consists essentially of PhSiO 3/2 units and CH2═CH(CH 3 ) 2 SiO 1/2 units.
9. The method according to claim 1 , wherein the photoactivated hydrosilylation catalyst is a platinum(II) β-diketonate.
10. The method according to claim 9 , wherein the platinum (II) β-diketonate is platinum(II) bis(2,4-pentanedioate).
11. The method according to claim 1 , wherein the silicone core has a thickness of from 1 to 100 μm.
12. The method according to claim 1 , further comprising (vii) covering the lower clad layer and the silicone core with a second curable polymer composition to form a second polymer film and (viii) curing the second polymer film to form an upper clad layer, wherein the upper clad layer has a refractive index less than the refractive index of the silicone core.
13. The method according to claim 12 , wherein the second curable polymer composition is a curable silicone composition.
14. The method according to claim 13 , wherein the curable silicone composition is the silicone composition in step (iii).
15. The method according to claim 12 , wherein the upper clad layer has a thickness of from 5 to 200 μm.
16. A method of preparing a planar optical waveguide assembly, comprising the steps of:
(i) applying a curable polymer composition to a surface of a substrate to form a polymer film;
(ii) curing the polymer film to form a lower clad layer;
(iii) applying a silicone composition to the lower clad layer to form a silicone film, wherein the silicone composition comprises:
(A) an organopolysiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule,
(B) an organosilicon compound containing an average of at least two silicon-bonded hydrogen atoms per molecule in a concentration sufficient to cure the composition, and
(C) a catalytic amount of a photoactivated hydrosilylation catalyst;
(iv) exposing at least one selected region of the silicone film to radiation having a wavelength of from 150 to 800 nm to produce a partially exposed film having at least one exposed region and at least one non-exposed region;
(v) heating the partially exposed film for an amount of time such that the exposed region is substantially insoluble in a developing solvent and the non-exposed region is soluble in the developing solvent;
(vi) removing the non-exposed region of the heated film with the developing solvent to form a patterned film; and
(vii) heating the patterned film for an amount of time sufficient to form at least one silicone core having a refractive index of from 1.3 to 1.7 at 23° C. for light having a wavelength of 589 nm; wherein the lower clad layer has a refractive index less than the refractive index of the silicone core.
17. The method according to claim 16 , wherein the curable polymer composition is a curable silicone composition.
18. The method according to claim 17 , wherein the curable silicone composition is the silicone composition in step (iii).
19. The method according to claim 16 , wherein the substrate is silicon or silicon dioxide.
20. The method according to claim 16 , wherein the lower clad layer has a thickness of from 5 to 200 μm.
21. The method according to claim 16 , wherein the organopolysiloxane is an organopolysiloxane resin.
22. The method according to claim 21 , wherein the organopolysiloxane resin consists essentially of R 2 3 SiO 1/2 units and R 1 SiO 3/2 units, wherein the mole ratio of R 2 3 SiO 1/2 units to R 1 SiO 3/2 units is from 0.05 to 1.0, each R 1 is independently selected from hydrocarbyl, deuterium-substituted hydrocarbyl, and halogen-substituted hydrocarbyl, all free of aliphatic unsaturation, and R 2 is R 1 or alkenyl.
23. The method according to claim 22 , wherein the organopolysiloxane resin consists essentially of PhSiO 3/2 units and CH2═CH(CH 3 ) 2 SiO 1/2 units.
24. The method according to claim 16 , wherein the photoactivated hydrosilylation catalyst is a platinum(II) β-diketonate.
25. The method according to claim 24 , wherein the platinum (II) β-diketonate is platinum(II) bis(2,4-pentanedioate).
26. The method according to claim 16 , wherein the partially exposed film is heated at a temperature of from 50 to 250° C. for 0.1 to 10 min.
27. The method according to claim 16 , wherein the silicone core has a thickness of from 1 to 100 μm.
28. The method according to claim 16 , further comprising (viii) covering the lower clad layer and the silicone core with a second curable polymer composition to form a second polymer film and (ix) curing the second polymer film to form an upper clad layer, wherein the upper clad layer has a refractive index less than the refractive index of the silicone core.
29. The method according to claim 28 , wherein the second curable polymer composition is a curable silicone composition.
30. The method according to claim 29 , wherein the curable silicone composition is the silicone composition in step (iii).
31. The method according to claim 28 , wherein the upper clad layer has a thickness of from 5 to 200 μm.