Microbend fiber-optic temperature sensor

Patent · Sun Jan 01 00:00:00 EST 1995

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
• 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

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