Encoded particle having a grating with variations in the refractive index

• US 7,872,804 B2
• Filed: 10/10/2006
• Issued: 01/18/2011
• Est. Priority Date: 08/20/2002
• Status: Active Grant

• Current Assignee: Illumina Incorporated
• Original Assignee: Illumina Incorporated
• Inventors: Putnam, Martin A., Moon, John A.
• Primary Examiner(s): Lavarias; Arnel C
• Application Number:
  US11/546,027
• Publication Number:
  US 20100246005A1
• Time in Patent Office: 1,561 Days
• Field of Search: None
• US Class Current: 359/569
• CPC Class Codes: B01J 2219/00459 Beads
• CPC Class Codes: B01J 2219/00463 Directed sorting
• CPC Class Codes: B01J 2219/0047 Pins
• CPC Class Codes: B01J 2219/005 Beads
• CPC Class Codes: B01J 2219/00547 Bar codes
• CPC Class Codes: B01J 2219/00576 fluorophore
• CPC Class Codes: B01J 2219/00702 Processes involving means for analysing and characterising the products
• CPC Class Codes: B01L 3/54 Labware with identification means identification of carriers, materials or components in automatic analysers G01N35/00732
• CPC Class Codes: G03H 1/02 Details of features involved during the holographic process; Replication of holograms without interference recording
• CPC Class Codes: G03H 1/0272 Substrate bearing the hologram
• CPC Class Codes: G03H 2210/53 Coded object not directly interpretable, e.g. encrypted object, barcode
• CPC Class Codes: G03H 2230/10 Microhologram not registered to the substrate
• CPC Class Codes: G03H 2270/20 Shape
• CPC Class Codes: G03H 2270/24 Having particular size, e.g. microscopic

Abstract

Microparticles 8 includes an optical substrate 10 having at least one diffraction grating 12 disposed therein. The grating 12 having a plurality of colocated pitches Λ which represent a unique identification digital code that is detected when illuminated by incident light 24. The incident light 24 may be directed transversely from the side of the substrate 10 with a narrow band (single wavelength) or multiple wavelength source, in which case the code is represented by a spatial distribution of light or a wavelength spectrum, respectively. The code may be digital binary or may be other numerical bases. The micro-particles 8 can provide a large number of unique codes, e.g., greater than 67 million codes, and can withstand harsh environments. The micro-particles 8 are functionalized by coating them with a material/substance of interest, which are then used to perform multiplexed experiments involving chemical processes, e.g., DNA testing and combinatorial chemistry.

Claims

1. An encoded particle, comprising:

a particle substrate having a grating with a superposition of different predetermined regular periodic variations of an index of refraction disposed in the particle substrate along a grating axis and indicative of a code.

2. An encoded particle as in claim 1, wherein the particle substrate comprises a transparent dielectric material with the index of refraction in the dielectric material.

3. An encoded particle as in claim 1, wherein the superposition is provided so as to correspond to the code, the code identifying the encoded particle.

4. An encoded particle according to claim 1, wherein said particle substrate has an elongated shape and wherein said superposition of different regular periodic variations in the index of refraction occurs along a length of said particle substrate.

5. An encoded particle according to claim 1, wherein the code is readable based on the grating altering a light signal transmitted through the particle substrate transverse to the grating axis.

6. An encoded particle according to claim 1, wherein the superposition includes a combination of one or more individual sinusoidal spatial periods or pitches of refractive index variation along the particle substrate.

7. An encoded particle according to claim 1, wherein at least a portion of said particle substrate is made of a substantially single material and has the grating embedded therein.

8. An encoded particle according to claim 7, wherein said grating has a resultant refractive index variation within the single material at a grating location.

9. An encoded particle according to claim 1, wherein the particle substrate provides an output optical signal that is a result of passive, non-resonant scattering from said grating when illuminated by said incident light signal.

10. An encoded particle of claim 1, wherein said particle substrate is made of a material selected from the group:

glass, silica, plastic, rubber, and polymer.

11. An encoded particle of claim 1, wherein said code comprises a plurality of digital bits.

12. An encoded particle of claim 1, wherein said code comprises at least 3 predetermined bits.

13. An encoded particle of claim 1, wherein said code comprises at least 16 predetermined bits.

14. An encoded particle of claim 1, wherein said code comprises a plurality of bits, each bit having a plurality of states.

15. An encoded particle of claim 1, wherein said code comprises a plurality of bits, each bit having a corresponding spatial location and each bit in said code having a value related to an intensity of an output optical signal at the spatial location of each bit.

16. An encoded particle of claim 15, wherein the value of each bit corresponds to a magnitude of refractive index variation of a corresponding refractive index pitch in said grating.

17. An encoded particle of claim 1, wherein said particle substrate has a coating disposed on at least a portion of said particle substrate, at least a portion of said coating being made of a material that allows a sufficient amount of an incident light signal to pass through said material to allow detection of said code.

18. An encoded particle of claim 1, wherein at least a portion of said particle substrate has a 3-D shape selected from the group:

a cylinder, a sphere, a cube, and a pyramid.

19. An encoded particle of claim 1, wherein said particle substrate has a grating region where said grating is located and a non-grating region where said grating is not located.

20. An encoded particle of claim 1, wherein said grating is a thin grating or a blazed grating.

21. An encoded particle of claim 1, wherein said grating includes a plurality of gratings.

22. An encoded particle of claim 1, wherein each of said gratings has a different location within said particle substrate.