A Fabry–Perot Interferometer With Asymmetrical Tapered-Fiber for Improving Strain Sensitivity

An effective method, reducing the material volume of the air cavity by asymmetrical tapering fiber, is demonstrated to enhance the sensitivity of the strain sensor dramatically. High-sensitive strain sensors are fabricated through this method that splicing and tapering fiber with arc discharge at the misaligned center of the air cavity. The strain sensitivity of the sensor is measured to be ∼ 41.81 pm/μϵ at a resonant wavelength ∼ 1560 nm ranging from 0 to 500 μϵ. In addition, the experimental results show that the asymmetrical tapered-fiber enables both the material volume to smaller and the wall thickness to thinner, resulting in strain sensitivity higher. The proposed sensors have the advantages of fabricated repeatability, high sensitivity, and compact size, benefiting its practical sensing applications.