Encoding optical cavity output light

• US 20080186492A1
• Filed: 02/05/2007
• Published: 08/07/2008
• Est. Priority Date: 02/05/2007
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Kiesel, Peter, Bassler, Michael, Schmidt, Oliver
• Granted Patent: US 7,545,513 B2
• Time in Patent Office: Days
• US Class Current: 356/433
• 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 21/39 using tunable lasers

Abstract

Output light from an optical cavity includes, for each of a set of modes, an intensity function. Analyte can be positioned in the cavity, and a mode'"'"'s intensity function can be encoded to include information about an optical characteristic of an analyte. For example, the intensity function can include a peak, and its central energy, maximum intensity, contrast, or intermediate intensity width (e.g. FWHM) can indicate the optical characteristic. For example, the information can be about both refractive index and absorption of an analyte.

Claims

1. A method of using an optical cavity that is operable to provide output light in one or more modes;

when providing output light in one of the modes with analyte absent, the optical cavity providing the output light with a respective unencoded intensity function;

the method comprising;

positioning an analyte in the optical cavity, the analyte having a respective optical characteristic; and

while the analyte is positioned in the optical cavity, providing analyte-affected output light in at least one of the modes;

the analyte-affected output light from each mode having a respective encoded intensity function that is different than its unencoded intensity function;

the difference indicating the analyte'"'"'s optical characteristic.

2. The method of claim 1, further comprising:

photosensing the output light to obtain sensing results that depend on intensity function; and

using the sensing results to obtain information about the analyte'"'"'s optical characteristic.

3. The method of claim 1 in which the optical cavity is a Fabry-Perot cavity.

4. The method of claim 1 in which the cavity is an inhomogeneous optical cavity.

5. The method of claim 1 in which the analyte'"'"'s optical characteristic includes at least one of a refraction characteristic and an absorption characteristic.

6. The method of claim 1 in which the unencoded and encoded intensity functions each have a respective central value and in which the analyte'"'"'s optical characteristic includes a refraction characteristic;

the unencoded and encoded central values having a difference that indicates the refraction characteristic.

7. The method of claim 1 in which the unencoded and encoded intensity functions each have a respective maximum intensity or contrast and in which the analyte'"'"'s optical characteristic includes an absorption characteristic;

the unencoded and encoded maximum intensities or contrasts having a difference that indicates the absorption characteristic.

8. The method of claim 1 in which the unencoded and encoded intensity-energy functions each have a respective intermediate intensity width and in which the analyte'"'"'s optical characteristic includes an absorption characteristic;

the unencoded and encoded intermediate intensity widths having a difference that indicates the absorption characteristic.

9. The method of claim 8 in which each intermediate intensity width is a full width half maximum (FWHM).

10. The method of claim 1 in which the analyte'"'"'s optical characteristic includes both a refraction characteristic and an absorption characteristic.

11. The method of claim 1 in which the act of positioning the analyte comprises:

moving the analyte along a fluidic channel extending through the cavity.

12. The method of claim 1 in which the modes include at least one of transmission modes and reflection modes, the method further comprising:

illuminating the cavity so that it provides output light in only one mode.

13. The method of claim 1 in which the modes include at least one of transmission modes and reflection modes, the method further comprising:

illuminating the cavity so that it provides output light in two or more modes.

14. A system comprising:

an analyte positioning component that can position an analyte in an optical cavity, the optical cavity being operable to provide output light in one or more modes;

when providing output light in one of the modes with analyte absent, the optical cavity providing the output light with a respective unencoded intensity function;

the analyte having a respective optical characteristic; and

an optical cavity operating component that, while the analyte is positioned in the optical cavity, can operate the optical cavity to providing analyte-affected output light in at least one of the modes;

the analyte-affected output light from each mode having a respective encoded intensity function that is different than its unencoded intensity function;

the difference indicating the analyte'"'"'s optical characteristic.

15. The system of claim 14, further comprising control circuitry that provides signals to control the analyte positioning component and the optical cavity operating component.

16. The system of claim 14, further comprising:

an optical cavity structure that includes first and second light-reflective components and a light-transmissive region between them, the light-reflective components and light-transmissive region being operable as the optical cavity;

the optical cavity structure including an opening within the light-transmissive region;

the analyte positioning component transferring analyte into the opening.

17. The system of claim 16 in which the optical cavity is asymmetric when analyte is not in the opening and approximately symmetric when analyte is in the opening.

18. The system of claim 16 in which the opening is a well in a side of a biochip, the first light-reflective component being on a side of the biochip opposite the well;

the analyte positioning component further operating to cover the well with the second light-reflective component.

19. The system of claim 14, further comprising:

an optical cavity structure that includes two light-reflective components and a light-transmissive region between them, the light-reflective components and light-transmissive region being operable as the optical cavity;

the optical cavity structure including a set of one or more channels extending through the light-transmissive region;

the analyte positioning component transferring analyte through the light-transmissive region in the channels.

20. The system of claim 19 in which the set includes two or more channels.

21. The system of claim 19 in which the analyte is carried through the light-transmissive region by a fluid.

22. The system of claim 21 in which the analyte is a fluid that travels through the light-transmissive region in one or more of the channels in the set.

23. The system of claim 19 in which the channel travels through the light-transmissive region by traveling through a medium in one or more of the channels in the set.

24. A method of using an optical cavity that is operable to provide output light in one or more modes;

when providing output light in one of the modes with analyte absent, the optical cavity providing the output light with a respective unencoded intensity function;

the method comprising;

positioning each of a sequence of two or more analytes in the optical cavity, each analyte in the sequence having a respective optical characteristic, the optical characteristics of analytes varying within the sequence; and

while each analyte is positioned in the cavity, operating the optical cavity so that it provides respective analyte-affected output light in each of a subset of the modes, the respective analyte-affected output light of at least one mode in the subset having an intensity function that varies as a result of the varying optical characteristics of the analytes.

25. The method of claim 24 in which each analyte is in a respective object;

the act of positioning comprising;

moving each of a sequence of the analyte'"'"'s respective objects through the optical cavity.

26. A device comprising:

a Fabry-Perot cavity that is operable to provide output light in one or more of a set of transmission modes;

the cavity having an analyte region therein in which analyte can be positioned;

with analyte absent from the analyte region, the Fabry-Perot cavity being optically asymmetric;

with analyte present in the analyte region, the Fabry-Perot cavity being optically symmetric;

when operating in at least one mode in the set with analyte present in the analyte region, the Fabry-Perot cavity providing output light with a respective intensity function that, depends on an optical characteristic of the analyte moving each of a sequence of the analyte'"'"'s respective objects through the optical cavity.

27. The device of claim 26, further comprising an optical cavity structure that includes the Fabry-Perot cavity;

the Fabry-Perot cavity being one of a laser and a transmissive cavity.

28. The device of claim 26 in which the Fabry-Perot cavity provides output light in a mode with the mode'"'"'s respective intensity functions having a respective intensity peak.