P‐185: Passive Vibration‐Sensing System Using Hybrid Alignment Nematic Liquid‐Crystal Gratings

Unlike the commonly used electrically controlled birefringence mode liquid crystals, hybrid alignment nematic (HAN) liquid crystals eliminate the threshold voltage. Therefore, they have excellent application prospects in low‐voltage photonic components. This article discloses a power‐free vibration detection system based on optical fiber, HAN, and a passive vibration transducer. Using the photoalignment techniques, we fabricated HAN grating cells and deployed them into the vibration sensing system, achieving a sensitivity of 13.1 rad/m/s. Meanwhile, we measured the frequency response and resolution and analyzed its performance in actual conditions. The system has excellent costefficiency and optimization spaces, which can be applied in largescale vibration monitoring in the field.