Extrinsic Fabry-Perot Interferometer System Using Wavelength Modulated Source

Interferometric optical fiber sensors have proved many orders of magnitude more sensitive than their electrical counterparts, but they suffer from limitations in signal demodulation caused by phase ambiguity and complex fringe counting when the output phase difference exceeds one fringe period. Various signal demodulation methods have been developed to overcome some of the these drawbacks with limited success. This thesis proposes a new measurement system for the extrinsic Fabry-Perot interferometer (EFPI) sensor. Using a wavelength modulated source and a novel extended-gap EFPI, some of the limitations of interferometric signal demodulation are overcome. By scanning the output wavelength of a multilongitudinal mode laser diode through current modulation, the EFPI sensor signal is scanned through multiple fringes. Gap movement is then unambiguously determined by monitoring the phase of the multiple fringe pattern.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Electrical and Computer Engineering

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1996

Author dc:creator

• Meller, Scott A.

Chair dc:contributor.committeechair

• Wang, Anbo

Committee members dc:contributor.committeemember

• Murphy, Kent A.
• Claus, Richard O.

• optical fiber sensors
• interferometry
• multilongitudinal mode laser diode
• extrinsic fabry-perot interferometer
• pseudo-heterodyne modulation

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-15492117119623510

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/36516