An all polarization-maintaining fiber Mach-Zehnder interferometer for simultaneous measurement of acoustic pressure and temperature is examined. Measurements by Farahi et al. (1990) indicate that the cross-sensitivity between temperature and axial strain may be significant for a polarization-maintaining fiber Fabry-Perot interferometer; however, no one has examined the significance of cross-sensitivity for the Mach-Zehnder case. Sensitivities to acoustic pressure and temperature, and the cross-sensitivity generated by simultaneous disturbances are determined both analytically and numerically. The fiber’s relatively high temperature sensitivity compared with its acoustic pressure sensitivity suggests that a short length of sensing fiber is sufficient for use as a temperature sensor with little or no interference from acoustic pressure. To measure acoustic pressure, however, a straight length of the fiber examined in this study is not sufficient. In practice, this sensing fiber could be coiled around a compliant cylinder or into a small diameter sensing element to enhance longitudinal strain and thus sensitivity. Results show that in either case, the cross-sensitivity is extremely small and can be ignored.

1.
Butter
C. D.
, and
Hocker
G. B.
,
1978
, “
Fiber Optics Strain Gauge
,”
Applied Optics
, Vol.
17
, No.
18
, pp.
2867
2869
.
2.
Culshaw, B., Davies, D. E. N., and Kingsley, S. A., 1981, “Fiber Optic Strain Pressure and Temperature Sensors,” C. K. Kao, ed. Optical Fiber Technology II, IEEE Press, pp. 226–236.
3.
Dakin, J., and Culshaw, B., 1988, Optical Fiber Sensors: Principles and Components, Artech House, Inc.
4.
Farahi
F.
,
Webb
D. J.
,
Jones
J. D. C.
, and
Jackson
D. A.
,
1990
, “
Simultaneous Measurement of Temperature and Strain: Cross-Sensitivity Considerations
,”
Journal of Lightwave Technology
, Vol.
8
, No.
2
, pp.
138
142
.
5.
Hocker
G. B.
,
1979
, “
Fiber-Optic Sensing of Pressure and Temperature
,”
Applied Optics
, Vol.
18
, No.
9
, pp.
1445
1148
.
6.
Huang
S.
,
Blake
J. N.
, and
Kim
B. Y.
,
1990
, “
Perturbation Effects on Mode Propagation in Highly Elliptical Core Two-Mode Fibers
,”
Journal of Lightwave Technology
, Vol.
8
, No.
1
, pp.
23
33
.
7.
Hughes
R.
, and
Jarzynski
J.
,
1980
, “
Static Pressure Sensitivity Amplification in Interferometric Fiber-Optic Hydrophones
,”
Applied Optics
, Vol.
19
, No.
1
, pp.
98
107
.
8.
Lagakos
N.
,
Bucaro
J. A.
, and
Jarzynski
J.
,
1981
, “
Temperature-Induced Optical Phase Shift in Fibers
,”
Applied Optics
, Vol.
20
, No.
13
, pp.
2305
2308
.
9.
Meltz, G., Dunphy, J. R., and Leonberger, F. J., 1986, “Multi-Wavelength Twin-Core Fiber Optic Sensors,” Technical Digest Optical Fiber Sensors Conference.
10.
Timoshenko, S. P., and Goodier, J. N., 1970, Theory of Elasticity, Third Edition, Chap. 13, McGraw-Hill, Inc.
11.
Sanders, P. E., 1993, Personal Communication, 3M Specialty Optical Fibers, West Haven, CT 06516–5445.
12.
Wong
D.
, and
Chu
P. L.
,
1991
, “
Stress Calculations Based on Point-Matching Method for Mechanically Inhomogeneous Optical Fibers
,”
Journal of Lightwave Technology
, Vol.
9
, No.
1
, pp.
37
48
.
13.
Wong
D.
,
1992
, “
Effect of Fiber Coating on Temperature Sensitivity in Polari-metric Sensors
,”
Journal of Lightwave Technology
, Vol.
10
, No.
6
, pp.
842
846
.
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