Share Email Print

Proceedings Paper

High Pressure Fiber-Optic Sensor With Side-Hole Fiber
Author(s): K. Jansen; Ph. Dabkiewicz
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Experiments are performed toward the development of a fiber optic pressure sensor which uses the elasto-optic birefringence in a single-mode fiber. The 'side-hole' fiber-structure may be viewed as a PANDA-structure with open channels instead of the stress generating rods in its cross-section. The use of the side-hole fiber exploits the high reproducibility of silica serving as the elastic reference. By the side-hole geometry external hydrostatic pressure is converted into an anisotropic stress in the core region. Additionally, a stress concentration by a factor of 3 to 5 can be achieved by suitable choice of the geometry of the channels. In the experimental setup, the fiber is exposed in a pressure chamber directly to the pressure to be measured. The chamber is designed for a pressure range of 0 to 1000 bars.The induced birefringence is determined by passing a polarized laser beam through the fiber and by bi-directional counting the periods of phase delay between the two polarization-eigenstates of the fiber at the output. Thus, the sensor operates in an incremental mode. Using a fiber length of 10 cm, a pressure induced birefringence of 7.78 rad/(bar-m) was measured at a wavelength of 1300 nm. The resolution of optical phase evaluation is ni2, corresponding to a pressure resolution of approx. 2 bars. The overall accuracy of the sensor is better than ± 0.5% in the pressure range of 100-1000 bars where unambiguous phase evaluation was possible. Below 100 bars, in one fiber problems were caused near the point where the the birefringence vanishes. The experimental sensor-head is connected to the evaluation unit by a polarization-maintaining single-mode fiber, supplying the laser light, and three electrical leads for the detector signals. A version without any electrical lead to the sensor head is planned, in which the light source and the signal detectors are connected by optical fibers.

Paper Details

Date Published: 14 October 1987
PDF: 5 pages
Proc. SPIE 0798, Fiber Optic Sensors II, (14 October 1987); doi: 10.1117/12.941085
Show Author Affiliations
K. Jansen, Technische Universitat Hamburg-Harburg (Germany)
Ph. Dabkiewicz, Technische Universitat Hamburg-Harburg (Germany)

Published in SPIE Proceedings Vol. 0798:
Fiber Optic Sensors II
Anna Maria Verga Scheggi, Editor(s)

© SPIE. Terms of Use
Back to Top