Inter-fiber-cable Mach-Zehnder interferometer of writing linear waveguide based on femtosecond laser

Abstract

The invention provides an inter-fiber-cable Mach-Zehnder interferometer of writing linear waveguide based on femtosecond laser. The inter-fiber-cable Mach-Zehnder interferometer of writing linear waveguide based on femtosecond laser includes a broadband light source, a sensing head and a spectrum analyzer, wherein the sensing head is formed through writing of a linear waveguide in a fused single-mode-coreless-single-mode fiber through the femtosecond laser. The inter-fiber-cable Mach-Zehnder interferometer of writing linear waveguide based on femtosecond laser is characterized in that the femtosecond laser writes the linear waveguide in the fused single-mode-coreless-single-mode fiber, wherein the linear waveguide connects the fiber cores of the single-mode fibers at both ends of the coreless fiber; after completion of writing of the linear waveguide, one part of the light of the first section of single-mode fiber core is introduced out by the linear waveguide to penetrate the corelessfiber and transmit to the second section of single-mode fiber core, and one part of the light closely attaches to the linear guide so as to be transmitted to the next single-mode fiber core; and thelight of the broadband light source is transmitted to the spectrum analyzer through the sensing head, thus forming a Mach-Zehnder interferometer to measure the wavelength drift distance of the transmitted light spectral characteristic peak so as to calculate the values of the measured environmental parameters. The inter-fiber-cable Mach-Zehnder interferometer of writing linear waveguide based on femtosecond laser has the advantages of being firm in the apparatus, being low in cost, being small in volume, being high in sensitivity and the like, and can be used for high temperature and flexuralmeasurement.

Description

technical field [0001] The invention provides an in-line Mach-Zehnder interferometer based on a femtosecond laser writing linear waveguide, which belongs to the optical fiber sensing technology. Background technique [0002] Compared with traditional sensors, fiber optic sensors have extremely high sensitivity and resolution. In addition, their frequency band range is very wide, their dynamic range is large, and they are not easily disturbed by electromagnetic fields. In recent years, it has been practically applied in the Ministry of National Defense, scientific research departments, manufacturing industry, energy industry, medical and other scientific research fields. Among many fiber optic sensors, fiber optic sensors based on Mach-Zehnder have developed rapidly and become an important branch of fiber optic sensor research. Safety detection can also be used to monitor the curing state of composite materials, etc. It is of great significance for the safe use and integrit...

AI Technical Summary

Problems solved by technology

The above-mentioned structures have great disadvantages, and special optical fibers are expensive; the repeatability of optical fiber core dislocation fusion is difficult to achieve, and manual assembly requires a lot of time; micro-nano optical fibers and built-in air cavity equipment are fragile and poor in robustness

Furthermore, their free spectral range (FSR) is difficult to precisely control

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