Low-Temperature Crosstalk Bending Sensor With High Sensitivity Based on a Super-Structure Long-Period Fiber Grating

A novel super-structure long-period fiber grating (SLPFG) is proposed for bending measurement with high sensitivity. The experimental and simulated results show that the number of multimode fibers (MMF) in one period influences the excited coupling mode and its coupling efficiency. Meanwhile, the bend sensitivity is increased by optimizing the number of MMFs and reaches <inline-formula> <tex-math notation="LaTeX">$17.237\,\,\text {dB}/\text {m}^{-{1}}$ </tex-math></inline-formula>. More importantly, the temperature cross-sensitivity is one order of magnitude lower than most fiber bending sensors.