A strain-sensitivity-enhanced and asymmetric fiber-optic sensor based on anti-resonance hollow core fiber

We proposed a novel strain-sensitivity-enhanced optical fiber sensor with high strain sensitivity realized by anti-resonance hollow core fiber. The coreless fiber and the anti-resonance hollow core fiber were connected between the two single-mode fibers forming the sensor. Due to the unique structure, the sensor can be operated in transmission and reflection types. The results show that the strain sensitivity of the sensor can reach 23.02 dB/mε operating at the transmission type by welding with 18 mm anti-resonance hollow core fiber. Given a power resolution of 0.01 dBm, the strain resolution of the sensor can reach ∼0.43 με. The sensor has the advantages of high strain sensitivity, outstanding repeatability, excellent time responsiveness and temperature insensitivity which can be used for real-time and high-precision strain measurements in large temperature difference environments. Besides, it was significant for the strain-sensitivity-enhancement effect studying and the development of a new optical fiber sensor with anti-resonance hollow core fiber.