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Title: Method and apparatus for enhanced evanescent fluorescence and color filtering using a high refractive index thin film coating

Abstract

A technique for increasing the excitation and collection of evanescent fluorescence radiation emanating from a fiber optic sensor having a high refractive index (n.sub.r), dielectric thin film coating has been disclosed and described. The invention comprises a clad optical fiber core whose cladding is removed on a distal end, the distal end coated with a thin, non-porous, titanium dioxide sol-gel coating. It has been shown that such a fiber will exhibit increased fluorescence coupling due in part by 1) increasing the intensity of the evanescent field at the fiber core surface by a constructive interference effect on the propagating light, and 2) increasing the depth of penetration of the field in the sample. The interference effect created by the thin film imposes a wavelength dependence on the collection of the fluorescence and also suggests a novel application of thin films for color filtering as well as increasing collected fluorescence in fiber sensors. Collected fluorescence radiation increased by up to 6-fold over that of a bare fused silica fiber having a numerical aperture (N.A.) of O.6.

Inventors:
 [1];  [2];  [3]
  1. 2124 Promontory Cir., San Ramon, CA 94583
  2. 126 Echo Ave., Oakland, CA 94611
  3. 72 Bacon Ct., Lafayette, CA 94549
Publication Date:
Research Org.:
SANDIA CORP
OSTI Identifier:
873556
Patent Number(s):
US 6188812
Assignee:
Kao, Hung Pin (2124 Promontory Cir., San Ramon, CA 94583);Schoeniger, Joseph (126 Echo Ave., Oakland, CA 94611);Yang, Nancy (72 Bacon Ct., Lafayette, CA 94549)
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; enhanced; evanescent; fluorescence; color; filtering; refractive; index; film; coating; technique; increasing; excitation; collection; radiation; emanating; fiber; optic; sensor; dielectric; disclosed; described; comprises; clad; optical; core; cladding; removed; distal; coated; non-porous; titanium; dioxide; sol-gel; shown; exhibit; increased; coupling; due; intensity; field; surface; constructive; interference; effect; propagating; light; depth; penetration; sample; created; imposes; wavelength; dependence; suggests; novel; application; films; collected; sensors; 6-fold; bare; fused; silica; numerical; aperture; fused silica; sol-gel coating; numerical aperture; fiber optic; optical fiber; refractive index; titanium dioxide; film coating; radiation emanating; optic sensor; exhibit increased; clad optical; oxide sol-gel; fiber sensors; fluorescence radiation; interference effect; fiber sensor; evanescent fluorescence; color filter; /385/356/

Citation Formats

Kao, Hung Pin, Schoeniger, Joseph, and Yang, Nancy. Method and apparatus for enhanced evanescent fluorescence and color filtering using a high refractive index thin film coating. United States: N. p., 2001. Web.
Kao, Hung Pin, Schoeniger, Joseph, & Yang, Nancy. Method and apparatus for enhanced evanescent fluorescence and color filtering using a high refractive index thin film coating. United States.
Kao, Hung Pin, Schoeniger, Joseph, and Yang, Nancy. Mon . "Method and apparatus for enhanced evanescent fluorescence and color filtering using a high refractive index thin film coating". United States. https://www.osti.gov/servlets/purl/873556.
@article{osti_873556,
title = {Method and apparatus for enhanced evanescent fluorescence and color filtering using a high refractive index thin film coating},
author = {Kao, Hung Pin and Schoeniger, Joseph and Yang, Nancy},
abstractNote = {A technique for increasing the excitation and collection of evanescent fluorescence radiation emanating from a fiber optic sensor having a high refractive index (n.sub.r), dielectric thin film coating has been disclosed and described. The invention comprises a clad optical fiber core whose cladding is removed on a distal end, the distal end coated with a thin, non-porous, titanium dioxide sol-gel coating. It has been shown that such a fiber will exhibit increased fluorescence coupling due in part by 1) increasing the intensity of the evanescent field at the fiber core surface by a constructive interference effect on the propagating light, and 2) increasing the depth of penetration of the field in the sample. The interference effect created by the thin film imposes a wavelength dependence on the collection of the fluorescence and also suggests a novel application of thin films for color filtering as well as increasing collected fluorescence in fiber sensors. Collected fluorescence radiation increased by up to 6-fold over that of a bare fused silica fiber having a numerical aperture (N.A.) of O.6.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {1}
}

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