Micro-displacement sensor based on vernier effect, detection system and preparation system

The invention relates to the technical field of micro-displacement sensors, and discloses a vernier effect-based micro-displacement sensor, a detection system and a preparation system. The micro-displacement sensor comprises a single-mode fiber, a contact probe and an elastic support. One end of the elastic support is connected with the first end face of the single-mode optical fiber, and the other end of the elastic support is integrally connected with the second end face of the contact probe to form an air cavity; through the air cavity, the first end surface forms a first light reflecting surface, and the second end surface forms a second light reflecting surface; the third end surface of the contact probe forms a third light reflecting surface through an external substance; an open type elastic Fabry-Perot resonant cavity is formed between the first light reflecting surface and the second light reflecting surface, and a closed type Fabry-Perot resonant cavity is formed between the second light reflecting