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

Patent metadata

Field	Value
Publication number	US-9969647-B2
Application number	US-201615157223-A
Country	US
Kind code	B2
Filing date	May 17, 2016
Priority date	May 17, 2016
Publication date	May 15, 2018
Grant date	May 15, 2018

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 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:
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%;
wherein A is As, Sb or Ga, X is Cl, Br or I, and Z is S or Se; and
 wherein the glass composite comprises PbZ in a molar ratio of about 15% or less when A is As.

2. The glass composite of claim 1 , wherein A is Ga or As, X is Cl, and Z is Se.

3. The glass composite of claim 2 , wherein the mixture comprises:
GeSe 2 in a molar ratio of about 20% to about 30%, and
As 2 Se 3 in a molar ratio of about 65% to about 75%.

4. The glass composite of claim 3 , wherein the mixture comprises PbSe in a molar ratio of about 5% to about 15%.

5. The glass composite of claim 4 , wherein a molar ratio of CsCl is 0%.

6. The glass composite of claim 2 , wherein the mixture comprises:
GeSe 2 in a molar ratio of about 40% to about 60%, and
Ga 2 Se 3 in a molar ratio of about 20% to about 30%.

7. The glass composite of claim 6 , wherein the mixture comprises:
CsCl in a molar ratio of about 20% to about 30%, and a molar ratio of PbSe is 0.

8. The glass composite of claim 6 , wherein the mixture comprises:
CsCl in a molar ratio of about 0% to about 10%, and
PbSe in a molar ratio of about 5% or above.

9. The glass composite of claim 8 , wherein the molar ratio of PbSe is about 5% to about 30%.

10. The glass composite of claim 8 , wherein the PbSe comprises a plurality of crystallites in the phase-separated region.

11. The glass composite of claim 10 , wherein the PbSe is present in a nanocrystalline form.

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

13. 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 about 1.

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

15. The optical structure of claim 14 , wherein the glass composite defines a lens.

16. A method comprising:
providing a mixture comprising:
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%;
wherein A is As, Sb or Ga, X is Cl, Br or I, and Z is S or Se; and
wherein the mixture comprises PbZ in a molar ratio of about 15% or less when A is As;

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 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.

17. The method of claim 16 , wherein the mixture comprise:
GeSe 2 in a molar ratio of about 20% to about 30%, and
As 2 Se 3 in a molar ratio of about 65% to about 75%.

18. The method of claim 17 , wherein the mixture comprises PbSe in a molar ratio of about 5% to about 15%.

19. The method of claim 17 , wherein a molar ratio of CsCl is 0%.

20. The method of claim 16 , wherein A is Ga or As, X is Cl, and Z is Se.

21. The method of claim 20 , wherein the mixture comprises:
GeSe 2 in a molar ratio of about 40% to about 60%, and
Ga 2 Se 3 in a molar ratio of about 20% to about 30%.

22. The method of claim 21 , wherein the mixture comprises:
CsCl in a molar ratio of 0% to about 10%, and
PbSe in a molar ratio of about 5% or above.

23. The method of claim 21 , wherein the mixture comprises:
CsCl in a molar ratio of about 20% to about 30%, and a molar ratio of PbSe is 0.

24. The method of claim 16 , wherein locally heating the intermediate amorphous material comprises spot heating of a plurality of locations in the intermediate amorphous material with a laser.

Assignees

• Lockheed Corp
• Univ Central Florida Res Found Inc
• Lockheed Martin Energy Llc

Inventors

• Baleine Clara Rivero
• Richardson Kathleen
• Smith Charmayne

Classifications

• C03C23/0025

  by a laser beam · CPC title

• G02B3/0087

  with index gradient · CPC title

• C03C10/16 Primary

  Halogen containing crystalline phase · CPC title

• C03C4/10

  for infrared transmitting glass · CPC title

• C03C3/321

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