Polymide optical waveguide structures

Claim 2

A planar optical waveguide comprising: (a) a core for light transmission therethrough comprising a polyimide having repeating units of the formula (I): ##STR13## wherein R comprises from about 0 to about 100 mole percent ##STR14## and from about 100 to about 0 mole percent; ##STR15## (b) a cladding comprising a polyimide having repeating units of the formula (II): ##STR16## wherein R 2 comprises from about 0 to about 100 mole percent ##STR17## from about 100 to about 0 mole percent ##STR18## wherein R 1 and R 3 are independently selected from divalent hydrocarbon radicals; wherein the refractive index of the core is greater than the refractive index of the cladding; and wherein the difference between the birefringence of the core and the birefringence of the cladding is less than the difference between the TM refractive index of the core and the TM refractive index of the cladding, with the proviso that the core polyimide (I) and the cladding polyimide (II) are different and that at least one of the core polyimide (I) and the cladding polyimide (II) is a copolymer containing at least about 1 mole percent 3,3',4,4'-tetracarboxybiphenyl dianhydride moiety.

Claim 3

A planar optical waveguide according to claim 1 comprising: (a) a core for light transmission therethrough comprising a polyimide having repeating units of the formula (I): ##STR19## wherein R comprises from about 0 to about 100 mole percent: ##STR20## and from about 100 to about 0 mole percent: ##STR21## (b) a cladding comprising a polyimide having repeating units of the formula (II): ##STR22## wherein R 2 comprises from about 0 to about 100 mole percent: ##STR23## and from about 100 to about 0 mole percent: ##STR24## and wherein R 1 is at least one aromatic diamine and R 3 is at least one aromatic diamine which may be the same or different from R 1 ; wherein the refractive index of the core is greater than the refractive index of the cladding; and wherein the difference between the birefringence of the core and the birefringence of the cladding is less than the difference between the TM refractive index of the core and the TM refractive index of the cladding; with the proviso that the core polyimide (I) and the cladding polyimide (II) are different and that at least one of the core polyimide (I) and cladding polyimide (II) is a copolymer containing at least about 10 mole percent 3,3',4,4'-tetracarboxybiphenyl dianhydride moiety.

Claim 4

A planar optical waveguide according to claim 2 wherein at least one of the core polyimide (I) and the cladding polyimide (II) is a copolymer containing at least about 25 mole percent 3,3',4,4'-tetracarboxybiphenyl dianhydride moiety.

Claim 5

A planar optical waveguide according to claim 1 wherein at least one of the core polyimide (I) and the cladding polyimide (II) is a copolymer containing from about 1 mole percent to about 75 mole percent 3,3',4,4'-tetracarboxybiphenyl dianhydride moiety.

Claim 6

A planar optical waveguide according to claim 2 wherein at least one of the core polyimide (I) and the cladding polyimide (II) is a copolymer containing from about 10 mole percent to about 75 mole percent 3,3',4,4'-tetracarboxybiphenyl dianhydride moiety.

Claim 7

A planar optical waveguide according to claim 3 wherein at least one of the core polyimide (I) and the cladding polyimide (II) is a copolymer containing from about 25 mole percent to about 75 mole percent 3,3',4,4'-tetracarboxybiphenyl dianhydride moiety.

Claim 8

A planar optical waveguide according to claim 1 wherein R 1 and R 3 independently are at least one diamine selected from the group consisting of 4,4'-bis(p-aminophenoxy)biphenyl; 2,2-bis(4-aminophenyl) hexafluoropropane; 4,4'-oxydianiline; 1,3-bis(4-aminophenoxy)benzene; 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane; 4,4'-bis[4-amino-2-(trifiuoromethyl)phenoxy]biphenyl; 2,2'-bis[4-[4-amino-2-(trifiuoromethyl)phenoxy]phenyl]hexafluoropropane; and 2,2'-bis(trifluoromethyl)benzidine.

Claim 9

A planar optical waveguide according to claim 2 wherein R 1 and R 3 independently are at least one diamine selected from the group consisting of 4,4'-bis(p-aminophenoxy)biphenyl; 2,2-bis(4-aminophenyl)hexafluoropropane; 4,4'-oxydianiline; 1,3-bis(4-aminophenoxy)benzene; 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane; 4,4'-bis[4-amino-2-(trifluoromethyl)phenoxy]biphenyl; 2,2'-bis[4-[4-amino-2-(trifluoromethyl)phenoxy]phenyl]hexafluoropropane; and 2,2'-bis(trifluoromethyl)benzidine.

Claim 10

A planar optical waveguide according to claim 3 wherein R 1 and R 3 independently are at least one diamine selected from the group consisting of 4,4'-bis(p-aminophenoxy)biphenyl; 2,2-bis(4-aminophenyl)hexafluoropropane; 4,4'-oxydianiline; 1,3-bis(4-aminophenoxy)benzene; 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane; 4,4'-bis[4-amino-2-(trifluoromethyl)phenoxy]biphenyl; 2,2'-bis[4-[4-amino-2-(trifiuoromethyl)phenoxy]phenyl]hexafluoropropane; and 2,2'-bis(trifiuoromethyl)benzidine.

Claim 11

A planar optical waveguide according to claim 2 wherein R 1 and R 3 independently are at least one diamine selected from the group consisting of 2,2-bis(4-aminophenyl)hexafluoropropane; 2,2'-bis[4-[4-amino-2-(trifluoromethyl)phenoxy]phenyl]hexafluoropropane; 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane; and 4,4'-bis[4-amino-2-(trifluoromethyl)phenoxy]biphenyl.

Claim 12

A planar optical waveguide according to claim 3 wherein R 1 and R 3 independently are at least one diamine selected from the group consisting of 4,4'-bis(p-aminophenoxy)biphenyl; 4,4'-oxydianiline; 1,3-bis(4-aminophenoxy)benzene; and 2,2'-bis(trifluoromethyl)benzidine.

Claim 13

A planar optical waveguide according to claim 10 wherein R 1 and R 3 are 2,2-bis(4-aminophenyl)hexafluoropropane.

Claim 14

A planar optical waveguide according to claim 11 wherein R 1 and R 3 independently are at least one diamine selected from the group consisting of 4,4'-bis(p-aminophenoxy)biphenyl and 4,4'-oxydianiline.

Claim 15

A planar optical waveguide according to claim 1 wherein each of R and R 2 independently may optionally further contain up to about 25 mole percent of 3,3',4,4'-tetracarboxybenzophenone moiety.

Claim 16

A planar optical waveguide according to claim 1 wherein each of the core polyimide (1) and the cladding copolyimide (II) independently may optionally further contain a dopant.

Claim 17

A polyimide cladding for an optical waveguide which comprises a polyimide comprising the condensation product of 6FDA, at least about one mole percent BPDA, and at least one diamine selected from the group consisting of APBP, BAAF, and ODA.

Claim 18

A polyimide cladding for an optical waveguide which comprises a polyimide comprising the condensation product of 6FDA, at least about one mole percent BPDA, and at least one diamine selected from the group consisting of APBP, BAAF, and ODA.

Claim 19

The polyimide cladding of claim 16 wherein the polyimide comprises the condensation product of about 75 mole percent 6FDA, about 25 mole percent BPDA, and about 100 mole percent of a diamine selected from the group consisting of APBP and ODA.

Claim 20

The cladding of claim 16 wherein the polyimide comprises the condensation product of about 50 mole percent 6FDA, about 50 mole percent BPDA, and about 100 mole percent of a diamine selected from the group consisting of APBP and ODA.

Claim 21

The cladding of claim 16 wherein the polyimide comprises the condensation product of about 25 mole percent 6FDA, about 75 mole percent BPDA, and about 100 mole percent of a diamine selected from the group consisting of APBP and ODA.

Claim 22

A polyimide cladding for an optical waveguide which comprises a polyimide comprising the condensation product of 6FDA, at least about one mole percent BPDA, and about 100 mole percent of BAAF.

Claim 23

A polyimide cladding for an optical waveguide which comprises a polyimide comprising the condensation product of 6FDA, at least about one mole percent BPDA, and about 100 mole percent of BAAF.

Claim 24

The cladding of claim 20 wherein the polyimide comprises the condensation product of about 75 mole percent 6FDA, about 25 mole percent BPDA, and about 100 mole percent of BAAF.

Claim 25

The cladding of claim 20 wherein the polyimide comprises the condensation product of about 50 mole percent 6FDA, about 50 mole percent BPDA, and about 100 mole percent of BAAF.

Claim 26

The cladding of claim 21 wherein the polyimide comprises the condensation product of about 25 mole percent 6FDA, about 75 mole percent BPDA, and about 100 mole percent of BAAF.

Claim 29

A method according to claim 24 wherein the aromatic diamine in the core polyimide and the aromatic diamine in the cladding polyimide are independently at least one diamine selected from the group consisting of APBP, BAAF, ODA, 1,3,4-APB, BDAF, FAPB, Bis-AF-OFA, and TFMB.

Claim 30

A method according to claim 24 wherein the aromatic diamine in the core polyimide and the aromatic diamine in the cladding polyimide are independently at least one diamine selected from the group consisting of APBP, BAAF, and ODA.