Preparation method of fiber grating

Abstract

The invention relates to a preparation method of a fiber grating. The preparation method comprises the following steps: clamping a quartz glass matrix optical fiber performing bar on an optical fiber drawing tower to be molten and drawn, performing grating writing on the continuously descending bare fiber, coating the bare fiber with a coating, and performing ultraviolet curing, and at last reeling through a take-up reel, wherein the preparation method is characterized in that the grating writing adopts a phase-mask technique and uses a 193 nm excimer laser to perform monopulse exposure to write the bare fiber in the grating. The preparation method disclosed by the invention can be used for dynamically and continuously preparing the fiber grating array online, is simple, convenient and reasonable in process, and high in manufacturing efficiency; the grating written by the phase-mask technique and the 193 nm excimer laser is stable in central wavelength, good in spectral form, and high in consistency of grating reflectivity; the method can be used for preparing the high-quality grating array and solves the problems that the grating prepared by the fiber drawing tower online is poor in stability, low in reliability, poor in grating quality and low in efficiency; the prepared fiber grating array can be used for long-distance detection and signal transmission.

Description

technical field [0001] The invention relates to an online fiber grating preparation method, which belongs to the technical field of fiber grating preparation. Background technique [0002] Fiber Bragg grating is currently one of the most representative and promising fiber optic passive devices. It has the advantages of small insertion loss and high extinction ratio. There are a wide range of uses. In the field of fiber optic sensing, the advantages of fiber gratings are particularly prominent, and large-scale multiplexing will be able to form long-distance multi-parameter fiber grating sensing networks. [0003] A large number of fiber gratings are connected in series to form an array, which is the basis of a large-scale fiber grating sensor network. The traditional method of preparing fiber grating arrays is to first cut the finished optical fiber into sections, peel off the organic protective layer on the surface of the optical fiber, prepare the grating by laser exposur...

AI Technical Summary

Problems solved by technology

[0005] However, there are still some problems in the existing dynamic on-line method of fabricating fiber gratings: firstly, the gratings are fabricated by light-splitting optical path interference method, which is to change the Bragg wavelength written in the gratings by rotating the angle of two mirrors

Since the Bragg wavelength is very sensitive to the angle of the mirror, controlling the wavelength accuracy within 1nm requires a high-performance control device, so the control is difficult, resulting in poor consistency of the grating; second, the optical path used for writing is long, requiring After multiple reflections and turnings, a good vibration isolation platform and a stable working environment are required, but in the actual operation process, there are many influencing factors, which will also affect the poor consistency of the grating; third, the writing light source is 248nm laser , the uniformity of the laser beam, the stability of the laser pulse, the stability of the laser beam aiming point, and the low coherence make the prepared grating spectral shape poor and poor in consistency, resulting in low quality of the grating array

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