volume | PIER Journals

Abstract

An extrinsic Fabry-Perot cavity in optical fiber is used to achieve surface imaging at infrared wavelengths. The micro-cavity is realized by approaching a single mode fiber optic with a numerical aperture NA to a sample and it is fed by a low-coherence source. The measurement of the reflected optical intensity provides a map of the sample reflectivity, whereas from the analysis of the reflected spectrum in the time/spatial domain, we disentangle the topography and contrast phase information, in the limit of nearly homogeneous sample with complex permittivity having Im(ε) << Real(ε). The transverse resolution is not defined by the numerical aperture NA of the fiber and consequently by the conventional Rayleigh limit (about 0.6λ/NA), but it is a function of the transverse field behavior of the electromagnetic field inside the micro-cavity. Differently, the resolution in the normal direction is limited mainly by the source bandwidth and demodulation algorithm. The system shows a compact and simple architecture. An analytical model for data interpretation is also introduced.

1. Yu, B., et al. "Analysis of fiber Fabry-Pérot interferometric sensors using low-coherence light sources," IEEE Journal of Lightwave Technology, Vol. 24, No. 4, 1758-1767, Apr. 2006.
doi:10.1109/JLT.2005.863336

2. Murphy, K. A., M. F. Gunther, A. Wang, R. O. Claus, and A. M. Vengsarkar, "Extrinsic Fabry-Pérot optical fiber sensor," Proc. 8th Opt. Fiber Sens. Conf., 193-196, 1992.

3. Furstenau, N., M. Schmidt, H. Horack, W. Goetze, and W. Schmidt, "Extrinsic Fabry-Pérot interferometer vibration and acoustic systems for airport ground tra±c monitoring," Proc. Inst. Elect. Eng. --- Optoelectron, Vol. 144, No. 3, 134-144, 1997.
doi:10.1049/ip-opt:19971268

4. Wang, A., H. Xiao, J. Wang, Z. Wang, W. Zhao, and R. G. May, "Self-calibrated interferometric-intensity-based optical fiber sensors ," IEEE Journal of Lightwave Technology, Vol. 19, No. 10, 1495-1501, 2001.
doi:10.1109/50.956136

5. Yao, H.-Y. and T.-H. Chang, "Experimental and theoretical studies of a broadband superluminality in Fabry-Perot interferometer," Progress In Electromagnetics Research, Vol. 122, 1-13, 2012.
doi:10.2528/PIER11092707

6. Costa, F. and A. Monorchio, "Design of subwavelength tunable and steerable Fabry-Perot/leaky wave antennas," Progress In Electromagnetics Research, Vol. 111, 467-481, 2011.
doi:10.2528/PIER10111702

7. Han, M., Y. Zhang, F. Shen, G. R. Pickrell, and A.Wang, "Signal-processing algorithm for white-light optical fiber extrinsic Fabry-Perot interferometric sensors," Optics Letters, Vol. 29, No. 15, 1736-1738, Aug. 2004.
doi:10.1364/OL.29.001736

8. Chen, J. H., J. R. Zhao, X. G. Huang, and Z. J. Huang, "Extrinsic fiber-optic Fabry-Perot interferometer sensor for refractive index measurement of optical glass," Applied Optics, Vol. 49, No. 29, 5592-5596, Oct. 2010.
doi:10.1364/AO.49.005592

9. Zhou, X. and Q. Yu, "Wide-range displacement sensor based on fiber-optic Fabry-Perot interferometer for subnanometer measurement," IEEE Sensors Journal, Vol. 11, No. 7, 1602-1606, Jul. 2011.
doi:10.1109/JSEN.2010.2103307

10. Zhang, Y., H. Shibru, K. L. Cooper, and A. Wang, "Miniature fiber-optic multicavity Fabry-Perot interferometric biosensor," Optics Letters, Vol. 30, No. 9, 1021-1023, May 2005.
doi:10.1364/OL.30.001021

11. Wilkinson, P. R. and J. R. Pratt, "Analytical model for low finesse, external cavity, fiber Fabry-Perot interferometers including multiple re°ections and angular misalignment," Applied Optics, Vol. 50, No. 23, 4671-4680, Aug. 2011.
doi:10.1364/AO.50.004671

12. Kilic, O., M. J. F. Digonnet, G. S. Kino, and O. Solgaard, "Asymmetrical spectral response in fiber Fabry-Pérot interferometers," IEEE Journal of Lightwave Technology, Vol. 27, No. 24, 5648-5656, Dec. 2009.
doi:10.1109/JLT.2009.2032135

13. Daniels, D. J., Ground Penetrating Radar, 2nd Ed., IET, London, 2007.

14. Bouma, B. and G. Tearney, Handbook of Optical Coherence Tomography, Marcel Dekker, 2002.

15. Isikman, S. O., et al. "Lensfree on-chip microscopy and tomography for biomedical applications," IEEE Journal of Selected Topics in Quantum Electronics, Vol. 18, No. 3, 1059-1072, May{Jun. 2012.
doi:10.1109/JSTQE.2011.2161460

16. Di Donato, A., M. Farina, A. Morini, G. Venanzoni, D. Mencarelli, M. Candeloro, and M. Farina, "Using correlation maps in a wide-band microwave GPR," Progress In Electromagnetics Research B, Vol. 30, 371-387, 2011.

17. Farina, M., et al. "Disentangling time in a near-field approach to scanning probe microscopy," Nanoscale, Vol. 3, No. 9, 3589-3593, Sep. 2011.
doi:10.1039/c1nr10491h

18. Farina, M., et al. "Algorithm for reduction of noise in ultra-microscopy and application to near-field microwave microscopy," IET Elect. Lett., Vol. 46, No. 1, 50-52, Jan. 2010.
doi:10.1049/el.2010.2859

19. Kaklamani, D. I., "Full-wave analysis of a Fabry-Perot type resonator," Progress In Electromagnetics Research, Vol. 24, 279-310, 1999.
doi:10.2528/PIER99042601

20. Poularikas, A., The Transform and Application Handbook, 2nd Ed., CRC Press, 1999.

21. Lee, D. L., Electromagnetic Principles of Integrated Optics, John Wiley & Sons, 1986.

22. Ramo, S., J. R. Whinnery, and T. van Duzer, Fields and Waves in Communication Electronics, John Wiley & Sons, 1994.

23. Di Donato, A., et al. "Stationary mode distribution and sidewall roughness effects in overmoded optical waveguides," IEEE Journal of Lightwave Technology, Vol. 28, No. 10, 1510-1520, 2010.
doi:10.1109/JLT.2010.2045154

24. Di Donato, A., L. Scalise, and L. Zappelli, "Noncontact speckle-based velocity sensor," IEEE Transactions on Instrumentation and Measurement, Vol. 53, No. 1, 51-57, 2004.
doi:10.1109/TIM.2003.821482

25. Andretzky, P., et al. "Optical coherence tomography by `spectral radar,' dynamic range estimation and in vivo measurements of skin," Proc. SPIE 3567, Optical and Imaging Techniques for Biomonitoring IV , Vol. 78, Feb. 1999.

Dr. Andrea Di Donato

Dr. Antonio Morini

Prof. Marco Farina