Barometric pressure sensor with temperature compensation

Abstract

The invention discloses a pressure sensor with temperature compensation function, comprising a first single-mode optical fiber, a first capillary optical fiber, a gas-sensitive film, a second capillary optical fiber and a second single-mode optical fiber, the first single-mode optical fiber and the first capillary One end of the optical fiber is fused together; one end of the second capillary optical fiber is fused together with the second single-mode optical fiber, and the other end is sealed by a gas-sensitive membrane; the second capillary optical fiber is inserted into the first capillary optical fiber through the sealed end of the gas-sensitive membrane and inserted into the first capillary optical fiber. Fixed; the gas-sensitive film and the end face of the first single-mode optical fiber constitute a first FP interference cavity, and the side of the first capillary fiber in the first FP interference cavity is provided with a communication hole that communicates with the outside world; the gas-sensitive film and the second single-mode fiber are The end face of the mode fiber constitutes the second FP interference cavity, forming a cascaded double FP interference cavity differential structure.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to an air pressure sensor with a temperature compensation function. Background technique [0002] Fiber optic barometric pressure sensors are very important devices in the field of industrial and environmental monitoring. Common fiber optic air pressure sensors include grating type and various interference cavity types. The grating type air pressure sensor uses the change of the external air pressure to cause the change of the grating period and the effective refractive index of the mode, thereby causing the shift of the grating resonance wavelength to realize the air pressure measurement. Affected by the fiber material itself, the sensitivity of grating-type air pressure sensors is generally not high, usually not more than a few hundred pm / MPa. Among the interferometric barometric pressure sensors, the Fabry-Perot (FP) interferometric cavity has shown good potential...

AI Technical Summary

Problems solved by technology

The FP pressure sensors of these two structures have the problem of temperature crosstalk. The common method to solve the temperature crosstalk is to connect the Bragg grating in series for temperature compensation on the sensing structure, and the way of connecting the Bragg grating in series is only used to solve the temperature crosstalk. There is no gain in the sensitivity of the sensor itself

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