Ultra-sensitive stress sensor structure and system based on optical fiber

The invention discloses an ultra-sensitive stress sensor structure based on an optical fiber, which comprises a spiral structure coaxially arranged on the end face of the optical fiber and a flat plate structure arranged at the other end of the spiral structure and parallel to the end face of the optical fiber, and an FP resonant cavity is formed between the end face of the optical fiber and the flat plate structure. The invention also provides an ultra-sensitive stress sensor system based on the optical fiber. The FP type stress sensor can be directly machined on the end face of the single-mode optical fiber through the two-photon polymerization 3D machining technology, the technology is simple in preparation process and high in machining precision (the resolution ratio is superior to 200 nm), and the prepared micro-nano structure has extremely low surface roughness (generally lower than 80 nm) in combination with high-performance photoresist. And the sensing sensitivity of the obtained sensor can reach 0.43