OSA's Digital Library

Journal of the Optical Society of America A

Journal of the Optical Society of America A


  • Vol. 15, Iss. 8 — Aug. 1, 1998
  • pp: 2163–2171

Enhancement of evanescent fluorescence from fiber-optic sensors by thin-film sol-gel coatings

H. Pin Kao, Nancy Yang, and Joseph S. Schoeniger  »View Author Affiliations

JOSA A, Vol. 15, Issue 8, pp. 2163-2171 (1998)

View Full Text Article

Enhanced HTML    Acrobat PDF (383 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



A theoretical analysis and an experimental demonstration are presented to show the increase in collected evanescent fluorescence for a fiber-optic sensor having a high refractive-index (nr), titanium sol-gel, thin-film coating. Simulations indicated that the maximum collected fluorescence should increase and shift to smaller film thicknesses as nr increases and also predicted an interference color-filtering effect. Experimentally, collected fluorescence increased by as much as 6× over that from a bare fused-silica fiber having a numerical aperture of 0.60. Simulations and experimental data were consistent with a decrease in the effective nr as film thickness increases. Electron micrographs of the sol-gel structure supported this observation and showed that the structure differs significantly from that of films formed on a planar glass substrate. High nr, sol-gel thin films are a potentially inexpensive approach to significantly increasing the signal from fiber sensors.

© 1998 Optical Society of America

OCIS Codes
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(120.2440) Instrumentation, measurement, and metrology : Filters
(130.6010) Integrated optics : Sensors
(160.6060) Materials : Solgel
(260.2510) Physical optics : Fluorescence

Original Manuscript: September 22, 1997
Revised Manuscript: February 18, 1998
Manuscript Accepted: March 24, 1998
Published: August 1, 1998

H. Pin Kao, Nancy Yang, and Joseph S. Schoeniger, "Enhancement of evanescent fluorescence from fiber-optic sensors by thin-film sol-gel coatings," J. Opt. Soc. Am. A 15, 2163-2171 (1998)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. H. P. Kao, J. Biwersi, A. S. Verkman, “Fiber optic halide sensor based on fluorescence quenching,” in Fiber Optic Medical and Fluorescent Sensors and Applications, D. R. Hansman, F. P. Milanovich, G. G. Vurek, D. R. Walt, eds., Proc. SPIE1648, 194–201 (1992). [CrossRef]
  2. R. P. Ekins, “Competitive, noncompetitive and multianalyte microspot immunoassays,” in Immunochemistry of Solid-Phase Immunoassay, J. E. Butler, ed., (CRC Press, Boca Raton, Fla.,1991), pp. 105–139.
  3. C. K. Carniglia, L. Mandel, K. H. Drexhage, “Absorption and emission of evanescent photons,” J. Opt. Soc. Am. 62, 479–486 (1972). [CrossRef]
  4. T. R. Glass, S. Lackie, T. Hirschfeld, “Effect of numerical aperture on signal level in cylindrical waveguide evanescent fluorosensors,” Appl. Opt. 26, 2181–2187 (1987). [CrossRef] [PubMed]
  5. J. D. Andrade, R. A. Van Wagenan, D. E. Gregonis, K. Newby, J. N. Lin, “Remote fiber-optic biosensors based on evanescent-excited fluoro-immunoassay: concept and progress,” IEEE Trans. Electron Devices 32, 1175–1179 (1985). [CrossRef]
  6. E. H. Hellen, D. Axelrod, “Fluorescence emission at dielectric and metal-film interfaces,” J. Opt. Soc. Am. B 4, 337–350 (1987). [CrossRef]
  7. D. Axelrod, T. P. Burghardt, N. L. Thompson, “Total internal reflection fluorescence,” Annu. Rev. Biophys. Bioeng. 13, 247–268 (1984). [CrossRef] [PubMed]
  8. C. A. Browne, D. H. Tarrant, M. S. Olteanu, J. W. Mullens, E. L. Chronister, “Intrinsic sol-gel clad fiber-optic sensors with time-resolved detection,” Anal. Chem. 28, 2289–2295 (1996). [CrossRef]
  9. C. J. Brinker, M. S. Harrington, “Sol-gel derived antireflective coatings for silicon,” Sol. Energy Mater. 5, 159–172 (1981). [CrossRef]
  10. C. J. Brinker, A. J. Hurd, P. R. Schunk, G. C. Frye, C. S. Ashley, “Review of sol-gel thin film formation,” J. Non-Cryst. Solids 147 and 148, 424–436 (1992). [CrossRef]
  11. E.-H. Lee, R. E. Benner, J. B. Fenn, R. K. Change, “Angular distribution of fluorescence from liquids and monodispersed spheres by evanescent wave excitation,” Appl. Opt. 18, 862–868 (1979). [CrossRef]
  12. M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, Oxford, UK, 1980), p. 62.
  13. O. S. Heavens, Optical Properties of Thin Solid Films (Dover, New York, 1991), p. 57.
  14. N. J. Harrick, Internal Reflection Spectroscopy (Wiley, New York, 1967), pp. 13–63.
  15. R. W. Boyd, Radiometry and the Detection of Optical Radiation (Wiley, New York, 1983), p. 23.
  16. Carol S. Ashley, Sandia National Laboratories, Albuquerque, N. Mex. 87185-1349 (personal communication, 1997).
  17. H. P. Kao, J. S. Schoeniger, “Hollow cylindrical waveguides for use as evanescent fluorescence-based sensors: effect of numerical aperture on collected signal,” Appl. Opt. 36, 8199–8205 (1997). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited