Refractive index modulation device and method of refractive index modulation

• US 5,739,948 A
• Filed: 10/08/1996
• Issued: 04/14/1998
• Est. Priority Date: 10/12/1995
• Status: Expired due to Term

• Current Assignee: Dow, Inc.
• Original Assignee: Dow, Inc.
• Inventors: Nishida, Fumito, Ogawa, Takuya, Suzuki, Toshio, Kushibiki, Nobuo
• Primary Examiner(s): Ben, Loha
• Application Number:
  US08/730,721
• Time in Patent Office: 553 Days
• Field of Search: 359/321, 359/257, 359/258, 359/275, 359/350, 359/267, 359/361, 525/478, 528/15, 528/31, 528/32
• US Class Current: 359/321
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence

Abstract

A refractive index modulation element made of a refractive index modulation material. The refractive index can be thermally modulated. The refractive index modulation material can be a silicone resin represented by the following formula R_n SiO.sub.(4--n)/2,where the average value of n is 0.5 to 3 and where K is an aliphatic or aromatic group with 1 to 18 carbon atoms or other functional group. The silicone resin has a spectral transmission factor that on average is higher than 80%, within the wavelength range of 350 nm to 1,600 nm, and a refractive index temperature dependence of -0.001/°C. to -0.00005/°C.

Claims

1. A refractive index modulation device comprising a refractive index modulation element formed from a polysiloxane material having a spectral transmission factor on average higher than 80% within the range of 350 nm to 1,600 nm, and a refractive index temperature dependence of -0.001/°

C. to -0.00005/°

C.

2. The refractive index modulation device of claim 1 wherein said polysiloxane material consists essentially of a silicone resin with an average structure represented by R_n SiO.sub.(4--n)/2 where n is a number from 0.5 to 3, and R is selected from a group consisting of a hydrogen atom, a hydroxyl group, an epoxy group, an amine-containing function group, a saturated or non-saturated aliphatic hydrocarbon group having 1 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a halogenated hydrocarbon group having 1 to 18 carbon atoms, said silicone resin having a viscosity below 20,000 cP at a temperature between its melting point and 250°

C.

3. The refractive index modulation device of claim 2, wherein said polysiloxane material consists essentially of a silicone resin with an average structure represented by the formula R_nSiO.sub.(4--n)/2 where! n is a number greater than 0.5, but smaller than 3, and where R is an aliphatic or aromatic group with 1 to 18 carbon atoms.

4. A method of modulating the refractive index of the refractive index modulation element of claim 3, comprising modulating the temperature of the refractive index modulation element within a temperature range of -70°

to 250°

C.

5. The refractive index modulation device of claim 2 wherein the silicone resin is cured by an addition reaction between --SiH groups and vinyl groups, catalyzed with a platinum catalyst.

6. A method of modulating the refractive index of the refractive index modulation element of claim 5, comprising modulating the temperature of the refractive index modulation element within a temperature range of -70°

to 250°

C.

7. The refractive index modulation device of claim 1, wherein said polysiloxane material is formed from a mixture of:

a first silicone resin with an average structure represented by the formula R_n SiO.sub.(4--n)/2, where n is a number greater than 0.5, but smaller than 3, where R is an aliphatic or aromatic group with 1 to 18 carbon atoms and where an effective amount for curing of the R groups are alkenyl groups;

a second silicone resin with an average structure represented by the formula R'"'"'_n SiO.sub.(4-n)/2, where n is a number greater than 0.5, but smaller than 3, where R'"'"' is hydrogen, an aliphatic or aromatic group with 1 to 18 carbon atoms and where an effective amount for curing of the R'"'"' groups are hydrogen groups; and

a platinum curing catalyst.

8. A method of modulating the refractive index of the refractive index modulation element of claim 7, comprising modulating the temperature of the refractive index modulation element within a temperature range of -70°

to 250°

C.

9. The refractive index modulation device of claim 1, further comprising a light-propagating medium in contact with said refractive index modulation element.

10. The refractive index modulation device of claim 9, further comprising a heat application means in contact with said refractive index modulation element.

11. A method of manufacturing the refractive index modulation device of claim 1, comprising the steps of:

applying the polysiloxane material on a light-propagating medium,

hardening the applied polysiloxane material to form a refractive index modulating element, and then

placing a heat application means onto the refractive index modulating element.

12. A method of modulating the refractive index of the refractive index modulation element of claim 1, comprising modulating the temperature of the refractive index modulation element within a temperature range of -70°

to 250°

C.

13. A method of modulating the refractive index of the refractive index modulation element of claim 2, comprising modulating the temperature of the refractive index modulation element within a temperature range of -70°

to 250°

C.