Fiber optic temperature sensor using a Y{sub 2}O{sub 2}S:Eu thermographic phosphor

Conference · Wed Sep 01 04:00:00 EDT 1993

OSTI ID:10187917

Smith, T V ^[1]; Smith, D B ^[2]

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1. Bethel Coll., St. Paul, MN (United States). Dept. of Physics
2. Oak Ridge National Lab., TN (United States)

This report details the development and testing of a thermographic-phosphor-based fiber-optic temperature sensor. The sensor is constructed by removing a region of the fiber jacket and cladding, then coating the exposed core with yttrium oxysulfide doped with a europium activator (Y{sub 2}O{sub 2}S:Eu). When photoexcited, the europium in the host lattice emits a sharp-line fluorescence spectrum that is characteristic of the temperature of the host crystal lattice. By measuring fluorescence lifetimes, we can deduce the temperature of an optical fiber that is in thermal contact with the fiber. Two different distributions of Y{sub 2}O{sub 2}S:Eu in the cladding region were evaluated with regard to light coupling efficiency. Theoretical waveguide calculations indicate that a thin core/cladding boundary distribution of Y{sub 2}O{sub 2}S:Eu couples light more efficiently into the cores guided modes than does a bulk distribution of phosphor in the cladding. The sensor tests showed reproducible response from 20 to 180 degrees Celsius. This technique has several advantages over other fiber optic temperature sensing techniques: the temperature measurement is independent of the strain applied to the fiber; the measurements are potentially accurate to within half a degree centigrade; the sensor allows temperature to be measured at precise locations; and the method doesn`t preclude the use of the fiber for the simultaneous measurement of other parameters.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 10187917
• Report Number(s): CONF-9309199--5; ON: DE94000331
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606
440500
47 OTHER INSTRUMENTATION
EUROPIUM
FIBER OPTICS
FLUORESCENCE
MATERIALS
OPTICAL PYROMETERS
PHOSPHORS
PHYSICAL PROPERTIES
TEMPERATURE DEPENDENCE
TEMPERATURE MEASUREMENT
THERMAL INSTRUMENTATION
WAVEGUIDES
YTTRIUM OXIDES
YTTRIUM SULFIDES