Optical fiber refractive index sensor and manufacturing method thereof

Abstract

The invention belongs to the technical field of optical fiber sensing and provides a suspended core pohotonic crystal fiber refractive index sensor based on a four-wave mixing effect. The suspended core pohotonic crystal optical fiber refractive index sensor is composed of a high-power laser device, two half wave plates, a polarizer, a coupling lens, a suspended core pohotonic crystal optical fiber and a spectrograph. A covering layer of the suspended core pohotonic crystal optical fiber is provided with a plurality of air holes which are suspended at the periphery of a quartz fiber core through a sub-wavelength quartz arm; the fiber core of the fiber is small and the air holes of the covering layer are large; high nonlinear coefficient of the optical fiber is ensured, the length of the sensing optical fiber is reduced, and the air holes can be conveniently filled with liquid. Furthermore, the invention provides a manufacturing method of the suspended core pohotonic crystal fiber refractive index sensor based on the four-wave mixing effect; a zero dispersion wavelength of the suspended core pohotonic crystal fiber is close to a pumping wavelength so that generated Stokes waves and anti-Stokes waves are very sensitive to optical fiber dispersion and the refractive index sensing with the ultra-high sensitivity can be realized; the sensitivity can reach up to 105nm/RIU (Refractive Index Unit). The temperature crossing sensibility is avoided and the high-precision sensing measurement on reflective index micro-variables of the external environment is realized.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a suspended core photonic crystal optical fiber refractive index sensor and a manufacturing method thereof. Background technique [0002] Refractive index is an important physical parameter of matter, which is of great significance in biochemical sensing and detection. Compared with other sensors, optical fiber sensors have the advantages of small structure, high sensitivity, anti-electromagnetic interference, good insulation, corrosion resistance, and long-distance telemetry, which make them have certain advantages in refractive index measurement. Current typical optical fiber refractive index sensors include: optical fiber surface plasmon resonance (SPR) refractive index sensors, fiber grating refractive index sensors, and optical fiber refractive index sensors based on evanescent waves. These optical fiber refractive index sensors use the linear effe...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide an optical fiber refractive index sensor and its manufacturing method, which aims to solve the problems of small size of optical fiber air hole, low nonlinear coefficient of optical fiber, long sensing optical fiber length, and difficult liquid injection into optical fiber air hole , and further enhance the sensitivity of the sensor

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