Providing light to channels or portions

• US 20070147728A1
• Filed: 12/22/2005
• Published: 06/28/2007
• Est. Priority Date: 12/22/2005
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Kiesel, Peter, Schmidt, Oliver, Mohta, Setu
• Granted Patent: US 7,386,199 B2
• Time in Patent Office: Days
• US Class Current: 385/14
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/168 Specific optical properties, e.g. reflective coatings
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01N 21/65 Raman scattering

Abstract

A fluidity structure includes a channel, a portion of which can contain fluid. Light can propagate in the portion, such as in response to illumination. The refractive index of material at the portion'"'"'s boundary can be higher than that of the fluid, and more than approximately 10% of intensity of light propagating longitudinally occurs in the fluid, possibly approximately 90%. An IC can be positioned along the portion, with a set of cells of a photosensor array on the IC sensing photons emanating in response to the propagating light. The light can enter through a light-transmissive component along the channel'"'"'s boundary, then pass obliquely through a portion of the channel that contains air before passing through a bounding component and obliquely into the portion that can contain fluid. The light can couple to an anti-resonant waveguide mode.

Claims

1. A method of sensing photons emanating from a channel portion defined in a fluidity structure, the channel portion extending a length in a longitudinal direction and having, at each position along its length, a respective cross section;

in each position'"'"'s cross section, the channel portion having a boundary along most of which it is surrounded by material with higher refractive index than a fluid in the channel portion would have;

the method comprising;

with fluid in the channel portion, propagating light in the longitudinal direction through the channel portion so that, in cross sections along a part of the length, more than approximately 10% of light intensity from the propagated light occurs in the fluid; and

using a set of cells of a photosensor array on an IC positioned along the channel portion to sense photons emanating from the channel portion in response to the propagated light.

2. The method of claim 1 in which, in the cross sections along the part of the length, approximately 90% of light intensity from the propagated light occurs in the fluid.

3. The method of claim 1 in which the act of propagating light comprises:

providing light from a source outside the channel portion;

the light from the source entering the channel portion in an oblique direction relative to the longitudinal direction.

4. The method of claim 3 in which the fluidity structure includes a light-transmissive component along at least part of the channel portion'"'"'s boundary;

the light from the source being provided through the light-transmissive component.

5. The method of claim 4 in which the light-transmissive component has an approximately planar light entry surface that is oblique to the longitudinal direction;

the light from the source being provided at approximately normal through the exterior surface.

6. The method of claim 3 in which the fluidity structure includes an end component at an end of the channel portion, the end component including a light-transmissive portion;

the light from the source being provided through the light-transmissive portion of the end component.

7. The method of claim 6 in which the fluidity structure includes a light-transmissive component that extends In the longitudinal direction along at least part of the channel portion'"'"'s boundary and beyond the end component to a region in which a projection of the channel contains air;

the act of providing light through the light-transmissive portion comprising;

providing light from the source through the light-transmissive component to the projection of the channel and through the projection of the channel to the light-transmissive portion of the end component.

8. The method of claim 3 in which the act of providing light further comprises:

coupling the light from the source to an anti-resonant waveguide mode of the channel portion.

9. Apparatus comprising:

a fluidity structure;

defined within the fluidity structure, a channel portion that can contain fluid;

the channel portion extending a length in a longitudinal direction and having, in each position along its length, a respective cross section;

in each position'"'"'s cross section, the channel portion having a boundary along most of which it is surrounded by material with higher refractive index than the fluid;

an illumination component that provides light that propagates through the channel portion in the longitudinal direction;

in cross sections along a part of the length, more than approximately 10% of light intensity from the propagating light occurring in the fluid in the channel portion; and

an IC that includes a photosensor array with a set of cells along the channel portion;

the set of cells sensing photons emanating from the channel portion in response to the propagating light.

10. The apparatus of claim 9 in which the illumination component includes a source that provides light from outside the channel portion;

the light from the source entering the channel portion in a direction oblique to the longitudinal direction.

11. The apparatus of claim 10 in which the fluidity structure comprises:

a light-transmissive component along at least part of the channel portion'"'"'s boundary, the source providing light through the light-transmissive component.

12. The apparatus of claim 11 in which the light-transmissive component has an approximately planar exterior surface that is neither parallel nor perpendicular to the longitudinal direction;

the source providing light at approximately normal through the exterior surface.

13. The apparatus of claim 11 in which the light-transmissive component includes at least one of polydimethylsiloxane, polymer, glass, and quartz.

14. The apparatus of claim 10 in which the fluidity structure includes an end component at an end of the channel portion, the end component including a light-transmissive portion;

the source providing light through the light-transmissive portion.

15. The apparatus of claim 14 in which the fluidity structure includes a light-transmissive component that extends in the longitudinal direction along at least part of the channel portion'"'"'s boundary and beyond the end component to a region in which a projection of the channel portion contains air, gas, or vacuum;

the source providing light through the light-transmissive component to the projection of the channel portion and through the projection of the channel portion to the light-transmissive portion of the end component.

16. The apparatus of claim 15 in which the end component has a convex surface;

the convex surface focusing or collimating the light from the source.

17. The apparatus of claim 15 in which the end component has an oblique light entry surface.

18. The apparatus of claim 15 in which the fluidity structure further includes an outer component in the projection of the channel and outward from the end component, the air, gas, or vacuum being contained between the outer and end components.

19. The apparatus of claim 9 in which the illumination component includes at least one of a laser and a light-emitting diode.

20. A system that comprises the apparatus of claim 9, the system further comprising:

a processor connected to receive information from the set of cells.

21. Apparatus comprising:

a fluidity structure; and

defined within the fluidity structure, a channel portion extending in a longitudinal direction;

the fluidity structure including a light-transmissive bounding component between first and second portions of the channel;

the fluidity structure further having defined therein at least two ports through which fluid can enter and exit the first portion;

the bounding component being positioned so that light can enter the second portion at a first angle oblique to the longitudinal direction, pass through the bounding component, and enter the first portion of the channel at a second angle oblique to the longitudinal direction.

22. The apparatus of claim 21 in which the second angle is approximately 2°

or less.

23. The apparatus of claim 21 in which the fluidity structure further comprises a light-transmissive component that extends in the longitudinal direction along at least part of the second portion of the channel and has an exterior surface substantially parallel to the channel'"'"'s boundary;

the bounding component being positioned so that light can enter through the exterior surface of the light-transmissive component and exit into the second portion at the first angle.

24. The apparatus of claim 23 In which the iight-transmissive component has entry and exit ports defined therein through which fluid can enter and exit the first portion of the channel.

25. The apparatus of claim 21 in which light entering the first portion of the channel at the second angle couples to an anti-resonant waveguide mode of the first portion.

26. The apparatus of claim 21 in which the bounding component comprises at least one of gel, polydimethylsiloxane, polymer, photoresist, SU-8, glass, and quartz.

27. The apparatus of claim 21 in which the bounding component has a convex surface disposed away from the first portion of the channel;

the convex surface focusing or collimating the light from the second portion.

28. The apparatus of claim 21 in which the bounding component has an oblique light entry surface.

29. The apparatus of claim 21 in which the fluidity structure further includes an outer component in the second portion of the channel and outward from the bounding component, the second portion containing air, gas, or vacuum between the outer component and the bounding component.

30. A system that comprises the apparatus of claim 21, the system further comprising:

an IC that includes a photosensor array with a set of cells along the first portion of the channel, the set of cells sensing photons emanating from the first portion of the channel in response to the light entering from the bounding component; and

a processor connected to receive information from the set of cells.

31. The system of claim 30 in which the IC is separated from the fluidity structure by a gap so that the IC does not interfere with propagation of light in the first portion of the channel.

32. A method of producing an apparatus as in claim 21, the method comprising:

positioning the bounding component within the channel so that light can enter the second portion of the channel at a first angle oblique to the longitudinal direction, pass through the bounding component, and enter the first portion of the channel at a second angle oblique to the longitudinal direction.