Enhancing the optical characteristics of a gemstone

• US 20070157667A1
• Filed: 12/06/2006
• Published: 07/12/2007
• Est. Priority Date: 12/06/2005
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Witzens, Jeremy, Scherer, Axel, Maltezos, George
• Granted Patent: US 8,033,136 B2
• Time in Patent Office: Days
• US Class Current: 63/32
• CPC Class Codes: A44C 17/00 Gems or the like
• CPC Class Codes: A44C 17/001 Faceting gems
• CPC Class Codes: A44C 17/005 Gems provided with grooves or notches, e.g. for setting
• CPC Class Codes: G01N 21/87 Investigating jewels G01N21/88 takes precedence
• CPC Class Codes: G02B 5/18 Diffraction gratings holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44
• CPC Class Codes: G02B 5/1857 using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams

Abstract

Various embodiments described herein comprise a gemstone or other piece of jewelry, which incorporates one or more diffractive optical elements to enhance the fire displayed by the gemstone. In certain embodiments, the diffractive optical element comprises a diffraction grating etched on one or more facets of the gemstone.

Claims

1. A gemstone comprising:

a body comprising crystalline material; and

a diffractive optical element disposed on or in said body, said diffractive optical element comprising a plurality of diffractive features spaced with respect to each other to diffract visible light.

2. The gemstone of claim 1, wherein said body comprises a cut and polished gemstone.

3. The gemstone of claim 2, wherein said body comprises two or more facets and said diffractive optical element is disposed on at least one of said two or more facets.

4. The gemstone of claim 3, wherein said diffractive optical element is configured to preferentially direct light toward one or more junctions formed by two or more of said facets.

5. The gemstone of claim 3, wherein said facets are arranged in a configuration that increases brilliance of said gemstone and said diffractive optical element increases fire of said gemstone.

6. The gemstone of claim 3, wherein said facets are arranged in a configuration that emphasizes brilliance of said gemstone over fire and said diffractive optical element increases fire of said gemstone.

7. The gemstone of claim 3, wherein at least two of said two or more facets form a corner reflector with an angle between 60 and 120 degrees.

8. The gemstone of claim 1, wherein said crystalline material comprises naturally occurring diamond.

9. The gemstone of claim 1, wherein said crystalline material comprises synthetic diamond or synthetic or natural, ruby, sapphire, emerald, cubic zirconium, zircon, moissanite, topaz, rutile, strontium titanate, spinel, yttrium aluminum garnet, strontium titanate, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG).

10. The gemstone of claim 1, wherein said diffractive optical element comprises a patterned layer of material deposited onto said body.

11. The gemstone of claim 10, wherein said diffractive optical element comprises a diffraction grating composed of metal strips.

12. The gemstone of claim 1, wherein said diffractive optical element comprises indentations in said body.

13. The gemstone of claim 12, wherein said diffractive optical element comprises etches in said body.

14. The gemstone of claim 12, wherein bottoms of said indentations are substantially flat.

15. The gemstone of claim 12, wherein said diffractive optical element comprises a diffraction grating.

16. The gemstone of claim 15, wherein said plurality of diffractive features comprise a plurality of grooves.

17. The gemstone of claim 15, wherein a cross section of said diffraction grating substantially comprises a square wave.

18. The gemstone of claim 17, wherein the trough of said square wave is substantially flat.

19. The gemstone of claim 17, wherein the period of said square wave is on average approximately in the range of 4 to 20 microns.

20. The gemstone of claim 17, wherein the peak-to-trough amplitude of said square wave is on average approximately in the range of 20 to 600 nm.

21. The gemstone of claim 15, wherein the form factor of said diffraction grating is selected such that the majority of optical power incident upon the diffraction grating is coupled into the 0th and the ±

1 diffractive orders.

22. The gemstone of claim 21, wherein the fraction of light coupled into the 0th versus the ±

1 diffractive orders substantially varies as a fumction of wavelength in the visible spectrum.

23. The gemstone of claim 15, wherein the structure factor of said diffraction grating is selected such that the angular separation of the ±

1 diffractive orders from the 0th diffractive order, for a selected wavelength of visible light, is less than about 5°

.

24. The gemstone of claim 1, wherein said diffractive optical element comprises a two dimensional array of diffractive features.

25. The gemstone of claim 24, wherein said diffractive features are periodically spaced.

26. The gemstone of claim 25, wherein said diffractive features comprise cylindrical indentations.

27. The gemstone of claim 25, wherein the spacing between said plurality of diffractive features is quasi-periodic such that the feature-to-feature distance is distributed about a mean, or a finite number of means, with a standard deviation which does not exceed approximately one times said mean.

28. The gemstone of claim 24, wherein said plurality of diffractive features substantially comprises a sunflower structure, an Archimedean tiling, or a Penrose tiling.

29. The gemstone of claim 24, wherein said array of diffractive features comprises a square lattice, triangular lattice, or higher-order lattice.

30. The gemstone of claim 1, wherein said diffractive optical element comprises a design, logo, symbol, or other graphical feature.

31. The gemstone of claim 1, wherein said gemstone is incorporated into a piece of jewelry.

32. A gemstone comprising:

a body having a surface; and

a diffractive optical element comprising a plurality of diffractive features patterned in said body or on said surface of said body, said diffractive features spaced with respect to each other to diffract visible light.

33. The gemstone of claim 32, wherein said gemstone comprises a crystal, mineral, or mineraloid.

34. The gemstone of claim 32, wherein said gemstone is at least partially optically transmissive.

35. The gemstone of claim 32, wherein said gemstone comprises glass or some other optically transmissive material.

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56. Jewelry comprising:

a body comprising precious metal; and

a reflective diffractive optical element disposed on or in said body, said reflective diffractive optical element comprising a plurality of diffractive features spaced with respect to each other to diffract visible light.

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