All-fiber high accuracy sensor based on optical fiber multi-mode interference and application thereof

Abstract

The invention discloses an all-fiber high accuracy sensor based on optical fiber multi-mode interference and an application thereof. The all-fiber high accuracy sensor is composed of a first single-mode optical fiber, a multi-mode optical fiber, a coreless optical fiber and a second single-mode optical fiber. The first single-mode optical fiber, the multi-mode optical fiber, the coreless optical fiber and the second single-mode optical fiber are sequentially combined to be subjected to butt fusion. The specification of the first single-mode optical fiber is the same as the specification of the second single-mode optical fiber, the diameter of a core layer of the single-mode optical fiber is smaller than the diameter of a core layer of the multi-mode optical fiber, and the first single-mode optical fiber and the second single-mode optical fiber are used as the incidence end and the transmission end of a light source respectively. The multi-mode optical fiber is used as a mode coupler, the excitation efficiency of a high order mode in the coreless optical fiber is improved, and the coreless optical fiber serves as a measurement zone. The all-fiber sensor has the advantages of being low in cost, high in precision, small in size and compact in structure. A section of multi-mode optical fiber is used as the mode coupler, so that the measurement accuracy of the all-fiber high accuracy sensor is further optimized.

Description

technical field [0001] The invention relates to the fields of optical fiber sensing such as medical and health care, biological sensing, and environmental monitoring, and in particular to an all-fiber high-precision sensor based on the principle of optical fiber multimode interference (MMI) and its application. Background technique [0002] All-fiber sensor is an important field of engineering research on fiber optic sensing technology. Compared with traditional sensors, it has inherent advantages such as high safety, anti-electromagnetic interference, corrosion resistance, simple structure, small size, and high sensitivity. At the same time, this sensor based on the all-fiber structure is made of different types of optical fibers, which is low in cost, simple in manufacturing process, and sensitive advanced features. In recent years, with the development of optical fiber sensing technology and the in-depth research on all-fiber structural sensors at home and abroad, optic...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide an all-fiber high-precision sensor based on optical fiber multimode interference, which overcomes the shortcomings of traditional sensors, as well as the high cost and complicated manufacturing process of fiber Bragg gratings (FBG) and long-period gratings (LPG). defect

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