1Interdisciplinary Program of Biomedical Mechanical & Electrical Engineering, Pukyong National University, Busan 48513, Korea
2School of Electrical Engineering, Pukyong National University, Busan 48513, Korea
Correspondence to: Yong Wook Lee
(a) Schematic diagram of the fabrication setup for cascaded long-period fiber gratings (LPFGs) on polarization-maintaining photonic crystal fiber (PMPCF), (b) side-view image of the fabricated grating, and (c) its polarization-dependent in- fiber Mach-Zehnder interference spectra measured for orthogonal input polarization states denoted by polarizer angles of 0° (red) and 90° (blue). The inset of (b) shows a cross-sectional image of the PMPCF. SIDs A and B are the two fringe dips used as sensor indicators. (d) Schematic diagram of the proposed sensor and wavelength shifts of SIDs A (red) and B (blue), measured for applied (e) strain and (f) temperature changes.