Optical fiber sensor, manufacturing method and simultaneous measuring method for liquid temperature and refractive index

Abstract

The invention discloses an optical fiber sensor, a manufacturing method and a simultaneous measuring method for the liquid temperature and the refractive index. The optical fiber sensor comprises a monomode-coreless-monomode optical fiber structure, the monomode-coreless-monomode optical fiber structure is composed of an input optical fiber (1), an output optical fiber (3) and a coreless optical fiber (2) between the input optical fiber and the output optical fiber, the connecting position between the coreless optical fiber (2) and the input optical fiber (1) and the connecting position between the coreless optical fiber and the output optical fiber (3) are both in non-eccentric fusion welding, the related flexibility characteristic of the monomode-coreless-monomode structure of the optical fiber sensor to the liquid refractive index is utilized, and drift distances at two wave troughs in a transmittance spectrum of the optical fiber sensor are simultaneously monitored to achieve the purpose of simultaneously measuring the external refractive index and the external temperature. Compared with the prior art, the optical fiber sensor is simple in structure and easy to manufactured and can simultaneously measure the temperature and the refractive index accurately on the basis without increasing the manufacturing cost and improving the manufacturing difficulty.

Description

technical field [0001] The invention relates to the fields of optical fiber sensing and biochemistry, in particular to an optical fiber sensor capable of simultaneously measuring the refractive index and temperature of a liquid and a demodulation method thereof. Specifically, the invention relates to an optical fiber sensor based on a single-mode-coreless-single-mode all-fiber structure, and a method for demodulating it using a dual-wavelength method. Background technique [0002] Refractive index and temperature are two important parameters of liquid, and their real-time and accurate measurement is of great significance in biochemistry and other fields. Optical fiber sensors have received extensive attention and research in recent years because of their advantages such as small size, high sensitivity, anti-electromagnetic interference, and long sensing distance. On the basis of the traditional single-mode-multimode-single-mode fiber structure, people proposed to chemically...

AI Technical Summary

Problems solved by technology

However, due to the thermo-optic effect and thermal expansion effect of the silica material itself, its accuracy is easily disturbed by the external temperature when performing refractive index measurement. -Single-mode structure followed by a FBG method in series for simultaneous and accurate measurement of temperature and refractive index

However, this not only increases the volume of the sensor, but also increases the difficulty and cost of making the sensor.

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