Low-temperature drift refillable optical fiber FP sensor and preparation method thereof

Abstract

The invention belongs to the technical field of optical fiber sensing, and relates to a low-temperature drift refillable optical fiber FP sensor and a preparation method thereof. The preparation method comprises the following steps of flattening the end surfaces of a capillary quartz tube and an optical fiber and placing the capillary quartz tube and the optical fiber in an optical fiber fusion splicer; inserting the optical fiber into the capillary quartz tube by utilizing an alignment mechanism of the optical fiber fusion splicer so as to form an FP cavity; enabling the optical fiber and thecapillary quartz tube to be spliced and fixed at the fusion splicing area part and enabling a tiny gap to exist between the optical fiber and the capillary quartz tube; after the fusion splicing of the optical fiber at two ends, carrying out pressurization by utilizing the gap so as to fill a liquid sensitive material; and after the filling, sealing the end surface of the capillary quartz tube byusing ultraviolet curing glue. The optical fiber FP sensor is low in temperature sensitivity, simple to prepare, low in cost and easy to fill sensitive material, and has a wide application prospect;the interference cavity length of the optical fiber FP structure can be short; the output light is less in energy loss; and during the manufacturing, the sensor is good in consistency and the cavity length error can be controlled to 1 micron.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and relates to a fillable optical fiber FP sensor with low temperature drift and a preparation method thereof. Background technique [0002] Optical fiber FP interferometer, as one of the four major interferometers in optical fiber, has a wide range of applications in the field of optical fiber, such as demodulation of optical signals, acquisition of spectra, and signal sensing. Moreover, it has been widely used in the measurement of various physical and chemical quantities such as temperature, pressure, displacement, electromagnetic field, flow, speed, strain, etc. due to its simple and changeable structure and small size. Optical fiber FP sensor is the longest and most widely used optical fiber sensor. [0003] Fiber FP interferometers are mainly divided into intrinsic FP and extrinsic FP. "Intrinsic" means that the interference cavity is composed of optical fibers. This section...

AI Technical Summary

Problems solved by technology

The manufacture of this structure is relatively simple, and the cost of implementation is also very low. The length of the interference cavity is about 100-500 μm. After filling the sensitive material, the sensitive material has a large absorbance. To ensure the quality of the spectrum after filling, the length of the interference cavity should be as long as possible. Shortness reduces the light absorption of sensitive materials; however, it is more difficult to cut hollow-core fibers with shorter cavity lengths of 20-50 μm, requiring sophisticated cutting equipment

This structurally sensitive material is easily evaporated by high temperature during fusion splicing after filling, and the end face of the optical fiber cannot be coated with a reflective film to enhance the output spectrum

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