Claims
- 1. An apparatus for determining a physical parameter affecting an optical sensor, said apparatus comprising:
a) a source for emitting a radiation having a narrow linewidth at an emission wavelength λe; b) a means for varying said emission wavelength λe; c) an optical path for guiding said radiation to said optical sensor and guiding a response radiation from said optical sensor; d) a detector for generating a response signal to said response radiation; and e) an analysis module for fitting said response signal and determining therefrom said physical parameter.
- 2. The apparatus of claim 1, wherein said source is a narrow linewidth laser.
- 3. The apparatus of claim 2, wherein said narrow linewidth laser is a tunable laser selected from the group consisting of External Cavity Diode lasers, Distributed Bragg Reflector lasers, fiber lasers.
- 4. The apparatus of claim 1, wherein said analysis module comprises a curve fitting module for fitting a best fit curve to said response signal.
- 5. The apparatus of claim 1, wherein said optical sensor is selected from the group consisting of Bragg Gratings and Fabry-Perot elements.
- 6. The apparatus of claim 5, wherein said optical path comprises an optical fiber and said Bragg Grating is a Fiber Bragg Grating.
- 7. The apparatus of claim 1, wherein said means for varying said emission wavelength λe comprise a laser tuner.
- 8. The apparatus of claim 7, wherein said laser tuner comprises a scanner for scanning said emission wavelength λe.
- 9. The apparatus of claim 7, wherein said laser tuner comprises a sweeper for sweeping said emission wavelength λe.
- 10. The apparatus of claim 1, wherein said optical path comprises a waveguide.
- 11. The apparatus of claim 1, further comprising a tap for tapping said radiation and a wavelength meter for monitoring said emission wavelength λe.
- 12. A method for determining a physical parameter affecting an optical sensor, said method comprising:
a) emitting a radiation having a narrow linewidth at an emission wavelength λe; b) providing an optical path for said radiation to said optical sensor and for a response radiation from said optical sensor; c) varying said emission wavelength λe; d) generating a response signal from said response radiation; and e) determining said physical parameter from a fitting of said response signal.
- 13. The method of claim 12, wherein said optical sensor produces said response radiation by a varying a property of said radiation, said property being selected from the group consisting of transmittance, reflectance, absorbance and polarization.
- 14. The method of claim 12, wherein said emission wavelength λe is varied continuously.
- 15. The method of claim 14, wherein said emission wavelength λe is swept.
- 16. The method of claim 12, wherein said emission wavelength λe is varied discontinuously.
- 17. The method of claim 16, wherein said emission wavelength λe is scanned.
- 18. The method of claim 12, wherein said fitting comprises a best curve fit of said response signal.
- 19. The method of claim 18, wherein said fitting further comprises an analysis method selected from the group consisting of peak detection, Full Width Half Maximum (FWHM) determination, centroid detection.
- 20. The method of claim 18, wherein said fitting comprises a fit selected from the group consisting of a polynomial fit, a Lorentzian fit and a Gaussian fit.
- 21. The method of claim 12, wherein said physical parameter is selected from the group consisting of temperature, strain and pressure.
- 22. The method of claim 12, further comprising tapping said radiation and monitoring said emission wavelength λe.
RELATED APPLICATIONS
[0001] This application claims priority from provisional application 60/442,998 filed on Jan. 27, 2003.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60442998 |
Jan 2003 |
US |