A single optical fiber Michelson interference sensor and sensing system

Abstract

The present invention is applicable to the technical field of optical fiber sensors, and provides a single-fiber Michelson interference sensor, which includes a first chirped grating, a second chirped grating, and two chirped gratings written on the common single-mode optical fiber in sequence. Low-reflectance gratings with the same reflectance spectrum and a reflectivity below 1%. The invention also discloses a sensing system of a single optical fiber Michelson interference sensor, which includes a laser light source, an optical circulator, a photoelectric detector, a data acquisition card with A / D conversion, and computer signal processing. The single fiber Michelson interference sensor has the advantages of simple structure, convenient manufacture, high sensitivity, flexible configuration, anti-electromagnetic interference, corrosion resistance and can be used in harsh environments.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a single optical fiber Michelson interference sensor and a sensing system. Background technique [0002] Optical fiber Michelson interferometric sensors are widely used in optical fiber sensing, optical signal processing and other fields, including optical fiber stress sensing, optical fiber distributed vibration sensing, etc. Ordinary optical fiber Michelson interference sensors usually need to use an optical splitter to divide the power of the optical signal lamp from the light source, and then inject it into two separate optical fibers. When the light is reflected at the end faces of the respective optical fibers, they return to the optical Splitter, at this time, the optical splitter combines the returned light, and the two returned lights interfere, and the intensity is collected after photoelectric conversion, and the acquired signal may show a cosine periodic change. In s...

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Problems solved by technology

In this discrete optical path, the reference arm is susceptible to temperature, which can cause disturbances in the interference intensity

In order to simplify the interference structure of the optical fiber Michelson interferometric sensor, the patents "Michelson interferometer based on coaxial optical fiber" (patent number: ZL200910044807.4), "integrated miniature Michelson interferometric sensor in optical fiber and its manufacturing method" (patent number : ZL200910104579.5) and "Miniature optical fiber integrated optical fiber Michelson interference temperature sensor and manufacturing method" (Patent No.: ZL200910104580.8), etc., use optical fiber multiplexing or micromachining methods to construct optical fiber Michelson interference on a section of optical fiber sensor, but the above-mentioned method is complex in manufacturing process, difficult in mass production, and poor in practicability

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