Unambiguous sawtooth fringe counting for an active homodyne demodulated interferometric strain gauge

Author

Furstenau, Norbert ; Schiffer, Frank ; Schmidt, Walter

Author_Institution

Inst. for Flight Guidance, German Aerosp. Res. Establ., Braunschweig, Germany

Volume

13

Issue

7

fYear

1995

fDate

7/1/1995 12:00:00 AM

Firstpage

1237

Lastpage

1242

Abstract

Source wavelength modulation by feedback of the interference signal of an unbalanced fiber-optic Michelson interferometer to the driver of the semiconductor laser source gives rise to sawtooth-shaped fringe´s under fiber strain. The fringe asymmetry is utilized for elimination of the fringe counting directional ambiguity via differentiation of the closed-loop interference signal. Initial results of quantitative strain measurements agree reasonably well with the readout of a resistive strain gauge as well as with the theoretically predicted sensitivity

Keywords

Michelson interferometers; demodulation; fibre optic sensors; light interferometry; optical feedback; strain gauges; strain measurement; active homodyne demodulation; closed-loop interference signal; differentiation; driver; feedback; quantitative strain measurements; sawtooth fringe counting; semiconductor laser; sensitivity; source wavelength modulation; strain gauge; unbalanced fiber-optic Michelson interferometer; Capacitive sensors; Interference; Laser feedback; Optical feedback; Optical fiber cables; Optical fiber polarization; Optical fiber sensors; Optical interferometry; Optical refraction; Strain measurement;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.400693

Filename

400693