Nonlinear optical medium with a stable noncentrosymmetric polymeric structure

Claim 2

A process for producing a second order nonlinear optical medium having a stable noncentrosymmetric orientation of polymer molecules, which process comprises (1) heating a film of a polymer with pendant side chains to a temperature of at least about the polymer glass transition temperture(Tg); (2) subjecting the polymer medium to an external electric field to induce noncentrosymmetry in the polymer medium by molecular orientation of the polymer side chains which exhibit second order nonlinear optical susceptibility; and (3) cooling the noncentrosymmetric polymer medium to a temperature between about Tg and 20°C to solidify the polymer medium while maintaining the electric field effect and the polymer molecular orientation, wherein the temperature cycle between Tg and 20°C is over a period of time sufficient to achieve ordered thermal relaxation and stabilization of the induced second order properties in the oriented polymer medium.

Claim 3

A process in accordance with claim 1 wherein the temperature cycle in step(3) is over a period between about thirty minutes and 300 hours.

Claim 4

A process in accordance with claim 1 wherein the glass transition temperature of the polymer is in the range between about 60 °C-250°C.

Claim 5

A process in accordance with claim 1 wherein the polymer is characterized by a recurring monomeric unit corresponding to the formula: where P' is a polymer main chain unit, S' is a side chain flexible spacer group having a linear chain length of about 1-20 atoms, M is a side chain pendant group which exhibits second order nonlinear optical susceptibility β, and where the recurring monomeric unit comprises at least 20 weight percent of the polymer, and the polymer has a glass transition temperature above about 60°C.

Claim 6

A process in accordance with claim 4 wherein the pendant M group in the polymer side chain contains a biphenyl structure.

Claim 7

A process in accordance with claim 4 wherein the pendant M group in the polymer side chain has the following structure: where X is -0-, -S-, -NR-, R is hydrogen or a C 1 -C 4 . alkyl substituent; and Z is -N0 2 , -CN, -CF 3 , -SO 3 CF 3 , -CH= or -

Claim 8

A process in accordance with claim 4 wherein the pendant M group in the polymer side chain contains a stilbene structure.

Claim 9

A process in accordance with claim 4 wherein the pendant M' group in the polymer side chain has the following structure: where X is -0-, -S-, -NR-, R is hydrogen or a C 1 -C 4 alkyl substituent; and Z is -N0 2 , -CN, -CF 3 , -SO 3 CF 3 , -CH= or -

Claim 10

A process in accordance with claim 4 wherein the S spacer group is -(CH 2 ) n -, where n is an integer between about 2-12.

Claim 11

A process in accordance with claim 4 wherein the polymer side chains contain the following structure: where n is an integer between about 2-12, X is -0-, -S-, -NR-, R is hydrogen or a C 1 -C 4 alkyl substituent; and Z is -N0 2 , -CN, -CF 3 , -SO 3 CF 3 , -CH= or -

Claim 12

A process in accordance with claim 4 wherein the polymer side chains contain the following structure: where n is an integer between about 2-12, X is -0-, -S-, -NR-, R is hydrogen or a C 1 -C 4 alkyl substituent; and Z is -N0 2 , -CN, -CF 3 , -SO 3 CF 3 , -CH= or -

Claim 13

A process in accordance with claim 4 wherein the polymer main chain is a polyvinyl structure.

Claim 14

A process in accordance with claim 4 wherein the polymer main chain is a polysiloxane structure.

Claim 15

A process in accordance with claim 4 wherein the polymer main chain is a polyoxyalkylene structure.

Claim 16

A process in accordance with claim 4 wherein the polymer main chain is a polyamide structure.

Claim 17

A process in accordance with claim 4 wherein the polymer main chain is a polyester structure.

Claim 18

A process for producing a second order nonlinear optical medium having a stable noncentrosymmetric molecular orientation of polymer molecules, which process comprises (1) heating a film of a polymer with pendant side chains to a temperature in the range between about the polymer glass transition temperature(Tg) and 30 C; (2) subjecting the heated polymer medium to an external electric field to induce noncentrosymmetry in the polymer medium by molecular orientation of the polymer side chains which exhibit second order nonlinear optical susceptibility; and (3) maintaining the noncentrosymmetric polymer medium in solid form in the temperature range between about Tg and 30°C while maintaining the electric field effect and the polymer molecular orientation, wherein the temperature cycle between Tg and 30 C is over a period of time between about thirty minutes and 300 hours sufficient to allow ordered thermal relaxation so as to stabilize the induced second order properties in the oriented polymer medium.

Claim 19

A process for producing a second order nonlinear optical medium having a stable noncentrosymmetric molecular orientation of polymer molecules, which process comprises (1) heating a film of a polymer with pendant side chains to a temperature in the range between about the polymer glass transition temperature(Tg) and 30 C; (2) subjecting the heated polymer medium to an external electric field to induce noncentrosymmetry in the polymer medium by molecular orientation of the polymer side chains which exhibit second order nonlinear optical susceptibility; and (3) maintaining the noncentrosymmetric polymer medium in solid form in the temperature range between about Tg and 30°C while maintaining the electric field effect and the polymer molecular orientation, wherein the temperature cycle between Tg and 30 C is over a period of time between about thirty minutes and 300 hours sufficient to allow ordered thermal relaxation so as to stabilize the induced second order properties in the oriented polymer medium.

Claim 20

A process in accordance with claim 17 wherein the heating of the polymer medium in the process steps is at a temperature in the range between Tg and 0.5 Tg ( C).

Claim 21

A process in accordance with claim 17 wherein the temperature cycle in step (3) is over a period between about 0.5-60 hours.

Claim 22

A process in accordance with claim 17 wherein the polymer film has a thickness between about 0.1- ' 1000 microns.

Claim 23

A process in accordance with claim 17 wherein the external field is applied to the polymer film with a pair of electrodes having an applied voltage between about 10-1000 V/µm.

Claim 24

A process in accordance with claim 17 wherein the polymer is a polyacrylate or polymethacrylate polymer or copolymer which has pendant side chains which exhibit second order nonlinear optical susceptibility β, and the pendant side chains contain a biphenyl or stilbene structure.

Claim 25

A second order nonlinear optical medium produced in accordance with the process of claim 1.

Claim 26

A second order nonlinear optical medium produced in accordance with the process of claim 4.

Claim 27

A second order nonlinear optical medium produced in accordance with the process of claim 17.

Claim 28

A second order nonlinear optical medium comprising a stable noncentrosymmetric orientation of polymer molecules, wherein the polymer has side chains which exhibit second order nonlinear optical susceptibility, and wherein there is less than about 10 percent loss of second order nonlinear optical activity exhibited by the medium when the medium is maintained at 50 °C for one year.

Claim 29

A second order nonlinear optical medium comprising a stable noncentrosymmetric orientation of polymer molecules, wherein the polymer has side chains which exhibit second order nonlinear optical susceptibility, and wherein there is less than about 10 percent loss of second order nonlinear optical activity exhibited by the medium when the medium is maintained at 50 °C for one year.

Claim 30

An optical light switch or light modulator device with a polymeric second order nonlinear optical component comprising a noncentrosymmetric medium of oriented polymer molecules, wherein the polymer has side chains which exhibit second order nonlinear optical susceptibility, and wherein there is less than about 10 percent loss of second order nonlinear optical activity exhibited by the optical medium when the medium is maintained at 50 C for one year.

Claim 31

An optical light switch or light modulator device with a polymeric second order nonlinear optical component comprising a noncentrosymmetric medium of oriented polymer molecules, wherein the polymer has side chains which exhibit second order nonlinear optical susceptibility, and wherein there is less than about 10 percent loss of second order nonlinear optical activity exhibited by the optical medium when the medium is maintained at 50 C for one year.

Claim 32

An optical light switch or light modulator device with a polymeric second order nonlinear optical component comprising an optical medium produced in accordance with the process of claim 1.

Claim 33

An optical light switch or light modulator device with a polymeric second order nonlinear optical component comprising an optical medium produced in accordance with the process of claim 4.

Claim 34

An optical light switch or light modulator device with a polymeric second order nonlinear optical component comprising an optical medium produced in accordance with the process of claim 17.