Temperature refractive index sensing system based on 22 asymmetric optical fiber coupling structure

The utility model discloses a temperature refractive index sensing system based on a 2 * 2 asymmetric optical fiber coupling structure. The sensing system comprises a light source, a leading-in single-mode optical fiber, the asymmetric optical fiber coupling structure, a leading-out single-mode optical fiber and a detection unit which are connected in sequence. The asymmetric optical fiber coupling structure comprises a first coupling single-mode optical fiber and a second coupling multi-mode optical fiber, wherein the middle part of the first coupling single-mode optical fiber and the middle part of the second coupling multi-mode optical fiber are coupled to form an asymmetric coupling area; the light source is connected with one coupling single-mode/multi-mode optical fiber through a leading-in single-mode optical fiber; the detection unit comprises an asymmetric coupling structure and a spectrograph; according to the scheme of the utility model, the device has the advantages of electromagnetic interference