Acoustically scanned low-coherence interrogated simultaneous measurement of absolute strain and temperature using highly birefringent fibers

Author

Sinha, Pranay G. ; Yoshino, Toshihiko

Author_Institution

Dept. of Electron. Eng., Gunma Univ., Japan

Volume

16

Issue

11

fYear

1998

fDate

11/1/1998 12:00:00 AM

Firstpage

2010

Lastpage

2015

Abstract

We have utilized a traveling acoustic pulse in a two-mode optical fiber to create a moving beam splitter coupling light from LP₀₁ to LP₁₁ mode. As these optical modes have different group velocities, a variable intermodal delay is generated as a function of acoustic pulse position in the fiber. The device can be used as a receiving interferometer in low-coherence interferometry to scan time delay for carrying out fast extended range absolute measurement using simple analog electronic circuits. With this scanning technique we demonstrate measurement of absolute strain over 1600 με in the temperature range from 20 to 60°C with resolutions of the order of 40 με and 0.7°C, respectively, employing highly birefringent fibers as sensing elements

Keywords

acousto-optical devices; birefringence; fibre optic sensors; light interferometry; measurement errors; optical elements; optical scanners; strain measurement; temperature measurement; 1600 mus; 20 to 60 C; 40 mus; LP₀₁ mode; LP₁₁ mode; absolute strain; absolute strain measurement; acoustic pulse position; acoustically scanned low-coherence interrogated simultaneous measurement; fast extended range absolute measurement; fibre optic sensors; group velocities; highly birefringent fibers; low-coherence interferometry; moving beam splitter; optical modes; receiving interferometer; scan time delay; scanning technique; simple analog electronic circuits; temperature mesurement; temperature range; traveling acoustic pulse; two-mode optical fiber; variable intermodal delay; Acoustic measurements; Acoustic pulses; Delay; Optical beam splitting; Optical coupling; Optical fibers; Optical interferometry; Optical pulse generation; Optical sensors; Strain measurement;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.730363

Filename

730363