fp air pressure sensor based on gas-sensitive film in optical fiber and preparation method thereof

Abstract

The invention discloses an FP air pressure sensor based on a gas-sensitive film in an optical fiber, comprising a single-mode optical fiber and a quartz capillary optical fiber; one end of the quartz capillary optical fiber is connected to the single-mode optical fiber, and the other end is a sealed end; the quartz capillary optical fiber is a sealed end; A gas-sensing film is arranged in the capillary fiber, and one side of the silica capillary fiber between the gas-sensing film and the single-mode fiber is provided with an air hole to form an FP air cavity; between the gas-sensing film and the sealing end form a sealed cavity. The cavity length of the optical fiber FP air cavity of the sensor of the invention and the refractive index of the gas in the cavity are both sensitive to the air pressure, and the volume is small, the sensitivity is high, and the preparation method is simple, easy and low in cost.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing and communication, and in particular relates to an FP air pressure sensor based on a gas-sensitive film in an optical fiber and a preparation method thereof. Background technique [0002] Fiber optic barometric pressure sensors are very important devices in the field of industrial and environmental monitoring. In the past few decades, cutting-edge FP interferometers (FPIs) based on various diaphragms have shown good potential in pressure sensing applications. Common optical fiber pressure sensors include grating type and FP type, etc. As for the grating type, the grating is usually used as a sensitive unit to convert the change of the external gas pressure into the expansion of the position of the grating region, that is, the change of the grating pitch, which brings spectral shift. Due to the change of air pressure, the deformation of the optical fiber (the main material is SiO2) ...

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Problems solved by technology

[0004] The present invention aims to solve the problem that the existing FP air pressure sensor is sensitive to air pressure based on the single parameter of the cavity length or the refractive index of the gas in the cavity, and provides an FP air pressure sensor based on a gas-sensitive film in an optical fiber and its preparation method. The length of the cavity and the refractive index of the gas in the cavity are sensitive to the pressure at the same time, and the volume is small and the sensitivity is high. The preparation method is simple and easy, and the cost is low.

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