Method for making long period optical fibre grating

Abstract

The present invention belongs to the field of fiber communication and fiber sensor technology, and relates to the manufacture of passive optical device and fiber sensor. The present invention features that the long period fiber grating is made with 10.6 micron wavelength and 20-24 KHz frequency CO2 laser pulse and the three-beam focusing optical system comprising one cylindrical lens and two planar mirrors in 120 deg angle. Laser beam is focused symmetrically onto bare fiber, and computer controlled one-dimensional translating platform is shifted for alternate fiber shift and exposure to complete the making of the long period fiber grating. The said making process can improve the bending features of the long period fiber grating effectively and eliminating physical deformation of the fiber and is simple and flexible. The made long period fiber grating is used widely in filtering and gain smoothing in fiber communication and as wavelength demodulating fiber sensing element.

Description

technical field [0001] The invention belongs to the technical fields of optical fiber communication and optical fiber sensing. The invention relates to a manufacturing method of a long-period optical fiber grating and a corresponding device, and relates to the manufacturing technology of an optical passive device and an optical fiber sensor device in an optical fiber communication system. Background technique [0002] Since A.M.Vengsarkar and others successfully wrote long period fiber grating (Long Period Fiber Grating, hereinafter referred to as LPFG) in optical fiber in 1995, LPFG has been widely used in the field of optical fiber communication and optical fiber sensing technology, such as using LPFG without backward Reflection, small insertion loss and other advantages have been developed into fiber band-pass / rejection filters, EDFA gain smoothers, etc.; in terms of optical fiber sensing, LPFG has higher sensitivity to temperature and strain than fiber Bragg gratings, ma...

AI Technical Summary

Problems solved by technology

Due to CO 2 When the laser is single-sidedly written, the fiber is only irradiated on one side, and the other side is not irradiated by the laser, which causes the angular distribution of the refractive index change of the fiber to be uneven in the cross-section of the fiber, resulting in the resonant wavelength of the programmed LPFG being different from the The direction of bending has a strong dependence, and the written LPFG is prone to bending deformation

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