Glass composites having a gradient index of refraction and methods for production thereof

Patent metadata

Field	Value
Publication number	US-11198637-B2
Application number	US-201815979379-A
Country	US
Kind code	B2
Filing date	May 14, 2018
Priority date	May 17, 2016
Publication date	Dec 14, 2021
Grant date	Dec 14, 2021

Abstract

Gradient refractive index (GRIN) materials can include multi-phase composites having substances with differing refractive indices disposed non-uniformly within one another. Particular glass composites having a gradient index of refraction can include: an amorphous phase, and a phase-separated region disposed non-uniformly within the amorphous phase. The glass composites include a mixture containing: GeZ 2 and A 2 Z 3 in a combined molar ratio of about 60% to about 95%, and CsX and PbZ in a combined molar ratio of about 5% to about 40%, where A is As, Sb or Ga, X is Cl, Br or I, and Z is S or Se. When A is As, the glass composites include PbZ in a molar ratio of about 15% or less. The amorphous phase and the phase-separated region have refractive indices that differ from one another. More particularly, A is Ga or As, X is Cl, and Z is Se.

First claim

What is claimed is the following:

1. A glass composite having a gradient index of refraction, comprising:
an amorphous phase; and
a phase-separated region locally produced and disposed non-uniformly within the amorphous phase;
wherein the amorphous phase has a first index of refraction, and the phase-separated region has a second index of refraction, the first index of refraction differing from the second index of refraction; and
wherein the glass composite comprises a mixture comprising:
at least one of GeS 2 or GeSe 2 and at least one of As 2 S 3 , As 2 Se 3 , Sb 2 S 3 , Sb 2 Se 3 , Ga 2 S 3 , or Ga 2 Se 3 in a combined molar ratio of 60% to 95%; and
at least one of CsCl, CsBr, CsI, PbS, or PbSe in a molar ratio of 5% to 40%.

2. The glass composite of claim 1 , wherein the glass composite has a transmission window of at least 1 micron to 12 microns.

3. The glass composite of claim 1 , wherein the first index of refraction and the second index of refraction differ by a value of up to 1.

4. An optical structure comprising the glass composite of claim 1 .

5. The optical structure of claim 4 , wherein the glass composite defines a lens.

6. The glass composite of claim 1 , wherein the mixture comprises GeSe 2 and As 2 Se 3 .

7. The glass composite of claim 6 , wherein the mixture comprises PbSe in a molar ratio of 5% to 15%.

8. The glass composite of claim 1 , wherein the mixture comprises GeSe 2 and Ga 2 Se 3 .

9. The glass composite of claim 8 , wherein the mixture comprises CsCl.

10. The glass composite of claim 8 , wherein the mixture comprises PbSe.

11. The glass composite of claim 10 , wherein the molar ratio of PbSe is 5% to 30%.

12. The glass composite of claim 10 , wherein the PbSe comprises a plurality of crystallites in the phase-separated region.

13. The glass composite of claim 12 , wherein the PbSe is present in a nanocrystalline form.

14. A method comprising:
providing a mixture comprising:
at least one of GeS 2 or GeSe 2 and at least one of As 2 S 3 , As 2 Se 3 , Sb 2 S 3 , Sb 2 Se 3 , Ga 2 S 3 , or Ga 2 Se 3 in a combined molar ratio of 60% to 95%; and
at least one of CsCl, CsBr, CsI, PbS, or PbSe in a molar ratio of 5% to 40%;
heating the mixture to form a melt;
cooling the melt below a glass transition temperature thereof to form an intermediate amorphous material; and
locally heating the intermediate amorphous material to locally produce and define a phase-separated region within an amorphous phase;
wherein the amorphous phase has a first index of refraction, and the phase-separated region has a second index of refraction, the first index of refraction differing from the second index of refraction; and
wherein the phase-separated region is disposed non-uniformly within the amorphous phase.

15. The method of claim 14 , wherein locally heating the intermediate amorphous material comprises spot heating of a plurality of locations in the intermediate amorphous material with a laser.

16. The method of claim 14 , wherein the mixture comprises GeSe 2 and Ga 2 Se 3 .

17. The method of claim 16 , wherein the mixture comprises PbSe.

18. The method of claim 16 , wherein the mixture comprises CsCl.

19. The method of claim 14 , wherein the mixture comprises GeSe 2 and As 2 Se 3 .

20. The method of claim 19 , wherein the mixture comprises PbSe in a molar ratio of 5% to 15%.

Assignees

• Lockheed Corp
• Univ Central Florida Res Found Inc

Inventors

• Baleine Clara Rivero
• Richardson Kathleen
• Smith Charmayne

Classifications

• C03C3/323 Primary

  containing halogen, e.g. chalcohalide glasses · CPC title

• C03C4/10

  for infrared transmitting glass · CPC title

• C03C4/04

  for photosensitive glass · CPC title

• C03C3/321

  Chalcogenide glasses, e.g. containing S, Se, Te · CPC title

• G02B3/0087

  with index gradient · CPC title