Optic fiber micro-structure displacement sensor

Abstract

The invention discloses an optic fiber micro-structure displacement sensor; a left displacement transmission block is arranged at the left end of an insulated protective shield and a sliding piston is arranged at the right end; a right displacement transmission block is arranged at the right end of the sliding piston; support rods externally sleeved with recovery springs are arranged on the right displacement transmission block and the insulated protective shield; displacement limiting blocks are arranged at the right ends of the support rods; one end of a left single-mode optic fiber passes through the left displacement transmission block and is connected with a broadband light source; one end of a right single-mode optic fiber passes through the sliding piston and the right displacement transmission block and is connected with a spectrum analyzer; the other end of the left single-mode optic fiber of the left single-mode optic fiber is connected with one end of a thin-core optic fiber and the other end of the right single-mode optic fiber is welded with the other end of the thin-core optic fiber; and a refraction index regulating cavity is processed on the cladding of the thin-core optic fiber. The optic fiber micro-structure displacement sensor with the structure has the advantages of simple structure, small volume, high mechanical strength, high sensitivity and high linearity and can be used as a displacement sensor, a refraction index sensor or a temperature sensor.

Description

technical field [0001] The invention belongs to the technical field of sensors, and in particular relates to a displacement all-fiber sensor. Background technique [0002] All-fiber sensors mainly include fiber grating sensors, fiber optic Mach-Zehnder (Mach-Zehnder) interferometer sensors, fiber optic Fabry-Pérot (Fabry–Pérot) interferometer sensors, and Sagnac (Sagnac) interferometer sensors. All-fiber sensors have been widely used to measure temperature, strain, magnetic field, current and displacement due to their small size, light weight, strong anti-electromagnetic interference ability, corrosion resistance, simple fabrication, high precision, easy integration and high resolution. physical quantity. The detection principle is that the change of the above physical quantity of the measured object causes the wavelength shift, phase change, polarization state change and intensity change of the reflection or transmission spectrum of the optical fiber, and then the measured...

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Problems solved by technology

[0004] At present, there are many reports on the application of Mach-Zehnder interference realized by purely using the optical fiber core dislocation process. Most all-fiber sensors, such as fiber gratings and fiber Fabry-Perot sensors, have complex manufacturing processes and high costs; others Traditional types of electronic sensors are bulky, complex in structure, and poor in resistance to external interference (including corrosion, electromagnetic interference, etc.); Mach-Zehnder interference structure sensors use complex fiber core adaptation structures and relatively poor mechanical strength

[0005] The publication number designed by using the principle of Mach-Zehnder interference is CN 103063238 A, and the title of the invention is "An all-fiber sensor based on Mach-Zehnder interference", which is used to test parameters such as external temperature, refractive index, liquid level and axial stress. The measurement sensor adopts a structure in which a multimode optical fiber is fused to the end of a single-mode optical fiber, a thin-core optical fiber is fused to the end of the multi-mode optical fiber, and a single-mode optical fiber is fused to the end of the thin-core optical fiber. This all-fiber sensor, multimode optical fiber and The length of the thin-core fiber will obviously affect the intensity of the interference spectrum and the free spectral range, and the longer the length, the lower the mechanical strength of the complex structure will affect the measurement range and sensitivity

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