FP (Fabry-Perot) barometric sensor based on gas-sensitive film in an optical fiber and preparation method thereof

Abstract

The invention discloses an FP (Fabry-Perot) barometric sensor based on a gas-sensitive film in an optical fiber. The FP barometric sensor comprises a single-mode optical fiber and a quartz capillary optical fiber, One end of the quartz capillary optical fiber is connected with the single-mode optical fiber, and the other end of the quartz capillary optical fiber is a sealed end; a gas sensitive film is arranged in the quartz capillary optical fiber, and an air hole is formed in one side of the quartz capillary optical fiber between the gas sensitive film and the single-mode optical fiber to form an FP air cavity; and a sealing cavity is formed between the gas sensitive film and the sealing end. The cavity length of the optical fiber FP air cavity of the sensor and the refractive index of gas in the cavity are sensitive to air pressure at the same time, the sensor is small in size and high in sensitivity, and the preparation method is simple and easy to implement 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] Optical fiber pressure sensor is a very important device in the field of industrial and environmental monitoring. Over the past few decades, cutting-edge FP interferometers (FPIs) based on various diaphragms have shown promising potential in pressure sensing applications. Common optical fiber pressure sensors include grating type and FP type, etc. As far as the grating type is concerned, the grating is usually used as the sensitive unit to convert the change of the external gas pressure into the expansion of the position of the grating area, that is, the change of the grating pitch. 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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