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

Technical Report · Mon Sep 01 04:00:00 EDT 1997

OSTI ID:10110245

Kao, H P; Yang, N; Schoeniger, J S

A theoretical analysis and experimental demonstration of the increase in collected evanescent fluorescence for a fiber optic sensor having a high refractive index, titanium sol gel, thin film coating is presented. Collected fluorescence increased by up to 6 X over that from a bare fiber having a numerical aperture of 0.60. The maximum collected fluorescence increased and shifted to smaller film thicknesses as the film refractive index increased. The simulations and experimental data are consistent with a decrease in the effective refractive index of the sol gel as the film thickness increased. Electron micrographs of the sol gel structure support this observation, and show that the sol gel structure is significantly different from those on a planar glass substrate. The sol gel technique is a potentially inexpensive approach to increase the signal from fiber sensors but higher photobleaching rates at the surface are predicted.

• Research Organization: Sandia National Labs., Chemical and Radiation Detection Lab., Livermore, CA (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 10110245
• Report Number(s): SAND--97-8287; ON: TI97020886
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606
CHEMICAL ANALYSIS
COATINGS
EFFICIENCY
FLUORESCENCE
MEASURING INSTRUMENTS
MORPHOLOGY
OPTICAL FIBERS
PHYSICAL PROPERTIES
SOL-GEL PROCESS
TITANIUM