| Title |
Polarimetric Fiber Curvature Sensor with Short Sensor Head Using Polarization-Diversity-Loop-Based Sagnac Interferometer |
| Authors |
Min Seok Kim; Sun Jae Jeong; Yong Wook Lee |
| DOI |
https://dx.doi.org/10.5207/JIEIE.2019.33.7.040 |
| Keywords |
Polarization-Maintaining Photonic Crystal Fiber; Curvature Sensor; Sagnac Interferometer |
| Abstract |
In this paper, we propose a polarimetric fiber curvature sensor using a polarization-diversity-loop-based Sagnac interferometer (PDLSI) composed of a polarization beam splitter, waveplates, and a 4.2-cm-long polarization-maintaining photonic crystal fiber (PMPCF) segment. To investigate the curvature response of the proposed sensor according to orientation angle of the slow axis of the PMPCF segment used as a sensor head, the axis was rotated around the direction of the light propagation by every 30°. When the slow axis of the PMPCF segment was parallel to a bending plane generated by bending of PMPCF, the comb spectrum of the PDLSI showed a red shift with increasing curvature radius. On the contrary, the comb spectrum of the PDLSI showed a blue shift with increasing curvature radius when the slow axis of PMPCF was perpendicular to the bending plane. The maximum curvature sensitivity was observed when the slow axis of PMPCF was parallel to the bending plane, and thus a curvature sensitivity of ～0.194nm/m-1 was attained in the measurement range of 20.39∼56.86m-1, showing an adjusted R2 value of ∼0.995, which represents a sensor linearity. |