Three methods for improving an axial strain sensitivity of polarization maintaining fiber loop mirror

Sensitivity is one of the important performances for sensor. Theoretical results show that we can choose a long wavelength monitoring point, a high strain dependent birefringence coefficient polarization maintaining fiber (PMF) and a low birefringence PMF to improve the axial strain sensitivity of PMF loop mirror, and experimental results show that the axial strain sensitivity has respectively been improved by 8.06, 30.73, and 22.26% by these methods. The advantage of these methods is to improve the axial strain sensitivity without increasing system complexity. These results help to improve the temperature, displacement, torsion, curvature and liquid level sensitivities of PMF loop mirror. These results can also be applied in photonic crystal fiber loop mirror.