Methods and systems for static multimode multiplex spectroscopy

• US 20040207855A1
• Filed: 04/16/2003
• Published: 10/21/2004
• Est. Priority Date: 04/16/2003
• Status: Active Grant

• Current Assignee: Duke University
• Original Assignee: Duke University
• Inventors: Brady, David J., Sullivar, Michael E.
• Granted Patent: US 7,092,101 B2
• Time in Patent Office: Days
• US Class Current: 356/451
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0205 Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
• CPC Class Codes: G01J 3/0256 Compact construction
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 3/4531 Devices without moving parts

Abstract

Methods and systems for static multimode multiplex spectroscopy are disclosed. According to a method for static multimode multiplex spectroscopy, spectral energy emanating from different points of a diffuse source is simultaneously received. Different multi-peak filter functions are applied to the spectral energy emanating from the different points to produce a multi-channel spectral measurement for each point. The multi-channel spectral measurements are combined to estimate a property of the diffuse source.

Claims

1. A method for static multimode multiplex spectroscopy, the method comprising:

(a) simultaneously receiving spectral energy emanating from a plurality of different spatial points of a diffuse source;

(b) applying different multi-peak filter functions to the spectral energy emanating from the different points to produce a multi-channel spectral measurement for each point; and

(c) combining the multi-channel spectral measurements for the different points to estimate a property of the diffuse source.

2. The method of claim 1 wherein simultaneously receiving spectral energy emanating from a plurality of different spatial points of a diffuse source includes receiving spectral energy emanating from a plurality of different spatial points of a biological sample.

3. The method of claim 2 wherein simultaneously receiving spectral energy emanating from a plurality of different points of a biological sample includes receiving spectral energy emanating from a plurality of different points of a tissue sample.

4. The method of claim 1 wherein simultaneously receiving spectral points from a plurality of different points of a diffuse source includes simultaneously receiving spectral energy emanating from a plurality of different points of a diffuse gas.

5. The method of claim 1 wherein applying different multi-peak filter functions to the spectral energy emanating from the different points includes passing the spectral energy from each point through a two-beam interfermoter having a different interference path length for the spectral energy emanating from each point.

6. The method of claim 1 wherein applying different multi-peak filter functions to the spectral energy emanating from the different points to produce a multi-channel spectral measurement for each point includes passing the spectral energy emanating from each point through an optical fiber and a fiber interferometer, wherein the fiber interferometer for each point has a different interferometric response.

7. The method of claim 1 wherein applying different multi-peak filter functions to the spectral energy emanating from the different points to produce a multi-channel spectral measurement for each point includes passing the spectral energy emanating from each point through a filter, wherein each filter has a different multi-peak response function.

8. The method of claim 7 wherein passing the spectral energy emanating from each point through a filter includes passing the spectral energy emanating from each point through a thin film filter.

9. The method of claim 7 wherein passing the spectral energy emanating from each point through a filter includes passing the spectral energy emanating from each point through a volume hologram.

10. The method of claim 7 wherein passing the spectral energy emanating from each point through a filter includes passing the spectral energy emanating from each point through an array of photonic crystals.

11. The method of claim 1 wherein simultaneously applying different multi-peak filter functions to the spectral energy emanating from the different points to produce a multi-channel measurement for each point includes sampling the spectral energy emanating from the different points using a detector array comprising a plurality of quantum dots and wherein combining the multi-channel spectral measurements for each point includes integrating over a plurality of spectral channels absorbed by the quantum dots.

12. The method of claim 1 wherein combining the multi-channel measurements to estimate a property of the source includes combining the multi-channel measurements to estimate an average spectrum of the source.

13. The method of claim 1 wherein combining the multi-channel measurements to estimate a property of the source includes combining the multi-channel measurements to estimate density of chemical compounds in the source.

14. The method of claim 12 wherein combining the multi-channel measurements to estimate an average spectrum of the source includes inverting the filter functions and integrating over an area of the source.

15. The method of claim 12 wherein combining the multi-channel measurements to estimate the average spectrum includes combining the spectral measurements for the different modes using the cross spectral density.

16. A system for static multimode multiplex spectroscopy, the system comprising:

(a) an illumination source for illuminating an object of interest;

(b) a filter/interferometer array for simultaneously receiving spectral energy emanating from a plurality of different points on the object of interest and for applying different multi-peak filter functions to the spectral energy emanating from the different points;

(c) a detector array optically coupled to the filter/interferometer array for receiving the filtered spectral energy and for converting the spectral energy into electrical signals; and

(d) a multi-peak spectral measurements combination module for receiving the electrical signals from the detector array and for combining the electrical signals to estimate a property of the object.

17. The system of claim 16 wherein the illumination source comprises first and second lasers.

18. The system of claim 16 wherein the filter/interferometer array comprises a two-beam interferometer having different interference path lengths for the spectral energy emanating from the different points.

19. The system of claim 16 wherein the filter/interferometer array comprises a plurality of fiber interferometers having different multi-peak interferometric responses.

20. The system of claim 16 wherein the fiber/interferometer array comprises a plurality of filters, wherein each filter has a different multi-peak response function.

21. The system of claim 20 wherein each filter comprises a thin-film filter having a plurality of layers.

22. The system of claim 16 wherein the fiber/interferometer array comprises a volume hologram.

23. The system of claim 16 wherein the fiber/interferometer array comprises an array of photonic crystals.

24. The system of claim 16 wherein the multi-peak spectral measurements combination module is adapted to combine the electrical signals to estimate an average spectrum of the object.

25. The system of claim 16 wherein the multi-peak spectral measurements combination module is adapted to combine the electrical signals to estimate a density of chemical compounds of the object.

26. The system of claim 16 wherein the multi-peak spectral measurements combinations module is adapted to invert the filter functions and integrate over an area of the object.

27. The system of claim 16 wherein the multi-peak spectral measurements combination module is adapted to combine spectral measurements for different modes of the object using cross spectral density of the modes.