Refractive index sensor based on mechanical suppression type long-period plastic fiber grating

Abstract

The invention relates to a refractive index sensor based on a mechanical suppression type long-period plastic fiber grating and belongs to the technical field of fiber grating sensors. The refractiveindex sensor based on the mechanical suppression type long-period plastic fiber grating is composed of a laser light source, a multimode plastic optical fiber, a first optical fiber fixing clip and asecond optical fiber fixing clip which can move in the horizontal direction, a long-period plastic optical fiber grating probe, an intelligent temperature control platform, an optical power meter anda data acquisition and processing system, wherein the long-period plastic optical fiber grating probe is one part of the multimode plastic optical fiber, an optical fiber cladding is eaten off, and acore layer is of a V groove array structure; the two ends of the probe are respectively clamped by the first optical fiber fixing clip and the second optical fiber fixing clip, one end of the multimode plastic optical fiber is connected with the laser light source, and the other end of the multimode plastic optical fiber is connected with the optical power meter. When light waves emitted from thelight source pass through the long-period plastic optical fiber grating probe, light density can be regulated by refractive index of to-be-detected solution contacted with the probe, and measurement on the refractive index of liquid is realized by utilizing the characteristic that the long-period optical fiber grating is sensitive to the refractive index.

Description

technical field [0001] The invention belongs to the technical field of optical fiber grating sensors, in particular to a mechanical pressing-based long-period plastic optical fiber grating refractive index sensor. Background technique [0002] As an important means of material analysis, refractive index measurement is of great significance in biochemical detection, environmental monitoring, medical diagnosis, food safety and so on. The fiber grating-based refractive index sensing technology has the advantages of high sensitivity, anti-electromagnetic interference, corrosion resistance, and compatibility with existing optical fiber systems, and has been extensively studied at present. [0003] The unique coupling mode of the long-period fiber grating determines that it is sensitive to the refractive index of the external environment, and the sensitivity can be further improved by cladding etching (such as the literature Del I V, Partridge M, Rodriguez W E, etal.Sensitivity En...

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Problems solved by technology

However, due to the hardness and fragility of quartz materials, the preparation process of long-period fiber gratings based on quartz materials is complicated and the cost is high.

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