OPTICAL SENSOR EMPLOYING A REFRACTIVE INDEX ENGINEERED METAL OXIDE MATERIAL

• US 20140321798A1
• Filed: 04/23/2014
• Published: 10/30/2014
• Est. Priority Date: 04/26/2013
• Status: Abandoned Application

• Current Assignee: US Department of Energy (Government of the United States of America), University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: National Energy Technology Laboratory (Government of the United States of America), University of Pittsburgh of The Commonwealth System of Higher Education
• Inventors: CHEN, PENG, POOLE, ZSOLT LEVENTE, OHODNICKI, PAUL R. Jr., BURIC, MICHAEL PAUL
• Application Number:
  US14/259,213
• Publication Number:
  US 20140321798A1
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: C03C 25/106 Single coatings
• CPC Class Codes: C03C 25/1061 Inorganic coatings
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/553 and using surface plasmons fluorescence excitation G01N21/648; enhanced Raman G01N21/658
• CPC Class Codes: G01N 21/774 the reagent being on a grating or periodic structure

Abstract

An optical sensor device includes an optical waveguide portion having a core, the core having a first refractive index, and a functional material layer coupled to the optical fiber portion, the functional material layer being made of a metal oxide material, the functional material layer being structured to have a second refractive index, the second refractive index being less than the first refractive index. The functional material layer may be a nanostructure material comprising the metal oxide material with a plurality of holes or voids formed therein such that the functional material layer is caused to have the second refractive index.

Claims

1. An optical sensor device, comprising:

an optical waveguide portion having a core, the core having a first refractive index; and

a functional material layer coupled to the optical waveguide portion, wherein the functional material layer comprises a metal oxide material, the functional material layer being structured to have a second refractive index, the second refractive index being less than the first refractive index.

2. The optical sensor device according to claim 1, wherein the functional material layer comprises a coating layer provided on a surface of the optical waveguide portion.

3. The optical sensor device according to claim 2, wherein the optical waveguide portion is a D-shaped optical fiber having a cladding layer having a hemispherical cross-section, the core being provided at least in part within the cladding layer, the coating layer being provided on a top, flat surface of the cladding layer and a top portion of the core.

4. The optical sensor device according to claim 3, further comprising an in-fiber optic component formed in the core.

5. The optical sensor device according to claim 4, wherein the in-fiber optic component is a Fiber Bragg Grating (FBG).

6. The optical sensor device according to claim 1, wherein the functional material layer is a nanostructure material comprising the metal oxide material with a plurality of voids termed therein such that the functional material layer is caused to have the second refractive index.

7. The optical sensor device according to claim 6, wherein the voids comprise about 60% of the nanostructure material causing the functional material layer to have a total volume fraction of voids of about 60%.

8. The optical sensor device according to claim 7, wherein the voids are spherical and each have a diameter of 100 nm or less.

9. The optical sensor device according to claim 8, wherein the voids are spherical and each have a diameter of about 10 nm to about 20 nm.

10. The optical sensor device according to claim 6, wherein the second refractive index is about 99.0% to about 99.7% of the first refractive index.

11. The optical sensor device according to claim 6, wherein the metal oxide in a bulk, fully dense form without the voids has a third refractive index greater than the first refractive index.

12. The optical sensor device according to claim 6, wherein the nanostructure material is formed using a sol-gel method.

13. The optical sensor device according to claim 12, wherein the sol-gel method uses a triblock copolymer as a structure directing agent.

14. The optical sensor device according to claim 13, wherein the triblock copolymer is poloxamer 407.

15. The optical sensor device according to claim 13, wherein in the sol-gel method the structure directing agent is mixed with SnCl₄ in Ethanol to form a precursor, the precursor is modified by addition of HCl and then heated.

16. The optical sensor device according to claim 1, wherein the metal oxide material is selected from a group consisting of a zeolite, SnO₂, TiO2, ZnO, WO₃, and a perovskite.

17. The optical sensor device according to claim 1, wherein the functional material layer is porous.

18. A method of making an optical sensor device, comprising:

providing an optical waveguide portion having a core; and

forming a functional material layer made of a metal oxide material, the functional material layer being coupled to the optical waveguide portion, the core having a first refractive index, the functional material layer being structured to have a second refractive index, the second refractive index being less than the first refractive index.

19. The method according to claim 18, wherein the functional material layer is porous.

20. The method according to claim 19, wherein the functional material layer is a nanostructure material comprising the metal oxide material with a plurality of voids formed therein such that the functional material layer is caused to have the second refractive index.

21. The method according to claim 19, wherein the voids comprise about 60% of the nanostructure material causing the functional material layer to have a total volume fraction of voids of about 60%.

22. The method according to claim 20, wherein the voids are spherical and each have a diameter of 100 nm or less.

23. The method according to claim 22, wherein the voids are spherical and each have a diameter of about 10 nm to about 50 nm.

24. The method according to claim 18, wherein the second refractive index is about 99.0% to about 99.7% of the first refractive index.

25. The method according to claim 20, wherein the metal oxide in a bulk, fully dense form without the voids has a third refractive index greater than the first refractive index.

26. The method according to claim 18, wherein the step of forming the functional material layer employs a sol-gel method.

27. The method according to claim 26, wherein the step of forming the functional material layer includes mixing a structure directing agent with a first compound in an alcohol or another solvent to form a precursor, modifying the precursor by addition of a second compound to form a modified precursor, and heating the modified precursor to form a heated modified precursor, wherein the functional material layer is formed using the precursor.

28. The method according to claim 27, wherein the first compound is SnCl₄ wherein the alcohol is ethanol, and wherein the second compound is 37% HCl in water.

29. The method according to claim 27, wherein the structure directing agent is a triblock copolymer.

30. The method according to claim 29, wherein the triblock copolymer is poloxamer 407.

31. An optical sensor device, comprising:

a multilayer hollow waveguide device having;

a hollow waveguide tube layer,

an intermediate layer provided inside the hollow waveguide tube layer; and

a metal oxide coating layer inside the intermediate layer.

32. The optical sensor device according to claim 31, wherein the intermediate layer is a reflective coating layer

33. The optical sensor device according to claim 32, wherein the reflective coating layer is provided directly on an inner surface of the hollow waveguide tube layer.

34. The optical sensor device according to claim 32, wherein the metal oxide coating layer is provided directly on an inner surface of the reflective coating layer.

35. The optical sensor device according to claim 32, wherein the reflective coating layer is a metal coating layer.

36. The optical sensor device according to claim 31, wherein the hollow waveguide tube layer is made of silica, plastic or metal.

37. The optical sensor device according to claim 31, wherein the hollow waveguide tube layer has a first refractive index, wherein the intermediate layer is a guiding layer having a second refractive index that is greater than the first refractive index, and the metal oxide coating layer is structured to have a third refractive index, the third refractive index being less than the second refractive index.