Waveguide

• US 6,285,816 B1
• Filed: 04/13/1999
• Issued: 09/04/2001
• Est. Priority Date: 04/13/1999
• Status: Expired due to Term

• Current Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Original Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Inventors: Miller, Lawrence W., Anderson, Marc A., Tejedor-Anderson, Maria Isabel
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): Mooney, Michael P.
• Application Number:
  US09/291,261
• Time in Patent Office: 875 Days
• Field of Search: 385/123, 385/125, 385/126-130, 385/141, 385/142, 385/144
• US Class Current: 385/141
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: C02F 2201/3228 Units having reflectors, e.g. coatings, baffles, plates, mirrors
• CPC Class Codes: C03C 17/23 Oxides C03C17/02 takes precedence
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2217/213 SiO2
• CPC Class Codes: C03C 2217/22 ZrO2
• CPC Class Codes: C03C 2217/228 Other specific oxides
• CPC Class Codes: C03C 2217/23 Mixtures
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: Y02W 10/37 using solar energy

Abstract

A waveguide comprising a transparent substrate and a metal oxide coating having the disclosed properties on the substrate can propagate light in an attenuated total reflection mode.

Claims

1. A waveguide for propagating light of a selected wavelength in an attenuated total reflection mode, the waveguide comprising;

a transparent internal reflection element (IRE); and

a particulate transition metal oxide coating on one or more surfaces of the IRE, the coating having a boundary parallel to the at least one IRE surface, wherein the coating does not scatter light of the selected wavelength and has a refractive index greater than that of the IRE.

2. The waveguide of claim 1, wherein the metal oxide is selected from the group consisting of titanium dioxide (TiO₂), silicon dioxide (SiO₂), magnesium dioxide (MnO₂), and titanium dioxide/zirconium dioxide (TiO₂/ZrO₂).

3. The waveguide of claim 2, wherein the coating on the substrate is TiO₂.

4. The waveguide of claim 1, wherein the IRE has an elongated shape.

5. The waveguide of claim 4, wherein the IRE is selected from the group consisting of a fiber and a planar sheet.

6. The waveguide of claim 1, wherein the IRE comprises a material selected from the group consisting of a glass or a plastic.

7. The waveguide of claim 6, wherein the transparent substrate is a fused-silica glass.

8. The waveguide of claim 6, wherein the IRE comprises acrylic.

9. An apparatus for photocatalytic conversion of an organic compound;

the apparatus comprising;

a waveguide coated with a photocatalyst for propagating light in an attenuated total reflection mode;

a light source for illuminating the photocatalyst with light having energy sufficient to activate the photocatalyst so that the light is propagated through the coated waveguide in an attenuated total reflection mode.

10. An apparatus as claimed in claim 9 wherein the waveguide comprises a transparent internal reflection element (IRE) and a particulate transition metal oxide coating on one or more surfaces of the IRE, the coating having a boundary parallel to the at least one IRE surface, wherein said coating has a refractive index greater than that of the IRE.

11. The apparatus of claim 10, wherein the metal oxide is selected from the group consisting of titanium dioxide (TiO₂), silicon dioxide (SiO₂), magnesium dioxide (MnO₂), and titanium dioxide/zirconium dioxide (TiO₂/ZrO₂).

12. The apparatus of claim 10, wherein the coating on the substrate is TiO₂.

13. The apparatus of claim 10, wherein the IRE has an elongated shape.

14. The apparatus of claim 13, wherein the IRE is selected from the group consisting of a fiber and a planar sheet.

15. The apparatus of claim 10, wherein the IRE comprises a material selected from the group consisting of a glass or a plastic.

16. The apparatus of claim 15, wherein the transparent substrate is a fused-silica glass.

17. The apparatus of claim 15, wherein the IRE comprises acrylic.

18. A method for making a waveguide, the method comprising the step of:

applying to an internal reflection element (IRE) a parallel coating of a particulate metal oxide coating having an index of refraction greater than that of the IRE.

19. A method as claimed in claim 18, wherein the IRE is selected from the group consisting of a fiber and a planar sheet.

20. A method as claimed in claim 18, wherein the IRE comprises a material selected from the group consisting of a glass or a plastic.

21. A method as claimed in claim 20, wherein the transparent substrate is a fused-silica glass.

22. A method as claimed in claim 20, wherein the IRE comprises acrylic.