Simultaneous measurement of torsion, strain and temperature using a side-leakage photonic crystal fiber loop mirror

Abstract

A fiber optic sensor for simultaneous measurement of multi-parameter is proposed. The fiber sensor is realized by a fiber loop mirror based on a piece of homemade side-leakage photonic crystal fiber. Affected by the group birefringence of the side-leakage photonic crystal fiber, which induced by the elliptical germanium-doped core and the linear side-leakage defect, the fiber loop mirror has different wavelength responses to torsion, strain and temperature at different interference fringe valleys. By monitoring the wavelength shifts of three selected valleys in the transmission spectrum, simultaneous measurement of torsion, strain and temperature is achieved. The maximal sensitivities to torsion, strain and temperature are 151.14 pm/°, 1 pm/με and 71 pm/°C, respectively.

Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review

“…These sensors provide lower sensitivities than sensors designed with HLB fibers, however, their main advantage is in their low intrinsic temperature sensitivity. Twist sensors configured in Sagnac loops that base on HLB fibers can, however, provide high twist/rotation sensitivities as demonstrated for sensors with elliptical core fibers [16], high-birefringent fibers with large side air holes [17] and side-leakage PCF [18,19]. Most of these approaches, however, exhibit non-negligible temperature dependence and require proper temperature compensation schemes (some solutions possess this capability intrinsically).…”

Multiparameter fiber-optic sensors: a review

“…Fiber loops (Fig. 38), when combined with an elliptical core PCF 131 or elliptical core side hole fiber, 132 can also yield a sensor for simultaneous measurement of three parameters: the fiber's torsional twist, temperature, and strain. In these reports, the elliptical core PCF or elliptical core side hole fiber exhibit group birefringence that is dependent on all three parameters.…”

Influence of light source on the sensitivity of a Polarization Maintaining Fiber Loop Mirror vibration sensor

“…1,2 They have been widely used in measuring strain, 3,4 temperature, 5 torsion, 6 curvature, 7,8 twist, 9 pressure 10 and liquid level. 11 A PM-FLM sensor is usually demodulated by a wavelength [12][13][14][15][16][17] or light intensity 18 monitored by an optical spectrum analyzer (OSA) or optical power meter. Compared with the measuring voltage devices, these devices are expensive.…”