Microbend fiber-optic temperature sensor

Patent · Sat Dec 31 23:00:00 EST 1994

OSTI ID:869900

Weiss, Jonathan D ^[1]

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1. Albuquerque, NM

A temperature sensor is made of optical fiber into which quasi-sinusoidal microbends have been permanently introduced. In particular, the present invention includes a graded-index optical fiber directing steady light through a section of the optical fiber containing a plurality of permanent microbends. The microbend section of the optical fiber is contained in a thermally expansive sheath, attached to a thermally expansive structure, or attached to a bimetallic element undergoing temperature changes and being monitored. The microbend section is secured to the thermally expansive sheath which allows the amplitude of the microbends to decrease with temperature. The resultant increase in the optical fiber's transmission thus allows temperature to be measured. The plural microbend section of the optical fiber is secured to the thermally expansive structure only at its ends and the microbends themselves are completely unconstrained laterally by any bonding agent to obtain maximum longitudinal temperature sensitivity. Although the permanent microbends reduce the transmission capabilities of fiber optics, the present invention utilizes this phenomenon as a transduction mechanism which is optimized to measure temperature.

• Research Organization: AT & T CORP
• DOE Contract Number: AC04-76DP00789
• Assignee: Sandia Corporation ()
• Patent Number(s): US 5419636
• OSTI ID: 869900
• Country of Publication: United States
• Language: English

Related Subjects

/374/250/385/
agent
allows
amplitude
attached
bimetallic
bonding
bonding agent
capabilities
changes
completely
contained
containing
decrease
directing
element
expansive
fiber
fiber optic
fiber optics
fiber-optic
graded-index
increase
index optical
introduced
laterally
light
longitudinal
maximum
measure
measure temperature
measured
mechanism
metallic element
microbend
microbend section
microbends
monitored
obtain
optical
optical fiber
optics
optimized
particular
permanent
permanent microbends
permanently
permanently introduced
phenomenon
plural
plurality
quasi-sinusoidal
quasi-sinusoidal microbends
reduce
resultant
section
secured
sensitivity
sensor
sheath
steady
structure
temperature
temperature change
temperature changes
temperature sensor
thermally
transduction
transmission
unconstrained
undergoing
utilizes