Optical fibre with end face having metal micro-nano structure, and preparation method and application method therefor

An optical fibre with an end face having a metal micro-nano structure, and a preparation method and an application method therefor. The metal micro-nano structure is a resonant cavity having a micro-nano structure on a metal thin film, and surface plasmon resonance is generated with the incidence of optical fibre guide waves. The preparation method therefor comprises aligning and pasting a metal micro-nano structure on the surface of a substrate and peeling and transferring same to an optical fibre end face. The application method therefor comprises making the optical fibre end face be in contact with or be close to a medium, and measuring the refractive index of the medium by measuring the reflection of the optical fibre guide waves by the resonant cavity having the metal micro-nano structure. By combining surface plasmon resonance of a resonant cavity having a metal micro-nano structure and an optical fibre guide wave technique, a new device and a new method are provided for a refractive index sensor with high performance, and an effective and simple device preparation method is provided.