Fabry-Perot spectral image measurement

1. A system for wide-range spectral measurement, comprising:

one or more broadband sources to illuminate a rugate tag, wherein the one or more broadband sources have a short broadband source coherence length, wherein the light from the one or more broadband sources illuminates the rugate tag at a first numerical aperture and is collected at a second numerical aperture that is different from the first numerical aperture;

an adjustable Fabry-Perot etalon to optically process the reflected light to extract spectral information with fine spectral resolution; and

a detector to detect reflected light from the rugate tag, wherein the reflected light is comprised of multiple narrow-band subsets of the illumination light having long coherence lengths and is optically processed using a plurality of settings for the adjustable Fabry-Perot etalon, and wherein the plurality of settings includes a separation of the Fabry-Perot etalon plates that is greater than the broadband source coherence length.

2. A system as in claim 1 , wherein light from the broadband source is reflected by a beam splitter toward a lens to illuminate the sample.

3. A system as in claim 1 , wherein the reflected light is imaged on to the adjustable Fabry-Perot etalon.

4. A system as in claim 1 , wherein the adjustable Fabry-Perot etalon is set at a first separation distance to measure a response at a first wavelength.

5. A system as in claim 4 , wherein the adjustable Fabry-Perot etalon is set at a second separation distance to measure a response at a second wavelength.

6. A system as in claim 1 , wherein the optically processed reflected light is imaged on to the detector.

7. A system as in claim 1 , wherein the adjustable Fabry-Perot etalon is separated from the detector by imaging optics.

8. A system as in claim 7 , wherein the imaging optics comprise one or more lenses.

9. A system as in claim 1 , wherein the adjustable Fabry-Perot etalon and the detector are combined in an integrated device.

10. A system as in claim 9 , wherein the integrated device comprises a backside imaging sensor.

11. A system as in claim 9 , wherein the integrated device comprises one or more movers.

12. A system as in claim 11 , wherein a mover of the one or more movers comprises a MEMS mover.

13. A system as in claim 11 , wherein a mover of the one or more movers comprises a piezoelectric mover.

14. A system as in claim 1 , wherein the separation of the Fabry-Perot etalon plates is less than the long coherence lengths.

15. A method of relative spectral measurement, comprising:

providing one or more broadband sources to illuminate a rugate tag, wherein the one or more broadband sources have a short broadband source coherence length, wherein the light from the one or more broadband sources illuminates the rugate tag at a first numerical aperture and is collected at a second numerical aperture that is different from the first numerical aperture;

providing an adjustable Fabry-Perot etalon to optically process the reflected light to extract spectral information with fine spectral resolution; and

providing a detector to detect reflected light from the rugate tag, wherein the reflected light is comprised of multiple narrow-band subsets of the illumination light having long coherence lengths and is optically processed using a plurality of settings for the adjustable Fabry-Perot etalon, and wherein the plurality of settings includes a separation of the Fabry-Perot etalon plates that is greater than the broadband source coherence length.