Research On Fabrication And Property Of High Temperature Regenerated Grating

Fiber Bragg Grating (FBG) is one kind of optical fiber passive device in which there is a refractive periodic distribution in formed along the core. FBG have lots of advantages such as Electromagnetic immunity, low insertion loss, light weight, small dimension, wavelength encoding and high sensitivity, making it an important element in the field of Optical fiber communication and optical fiber sensing. But the performance of normal FBG in high temperature is poor, because the grating structure would be erased when working a long time in high temperature, which limit the application of FBG in the field of high temperature environment such as aerospace, metallurgy, and petrochemical industry. So it is urgently to develop a high temperature resistant grating. The performance of regenerated grating formed by high temperature annealing is stable in the environment of over1100℃, making it ideal choice for high temperature sensing.In this thesis, grating regeneration was studied both theoretically and experimentally. The main work is as followed:Four different types of fiber were used to fabricate the regenerated grating and compared. Regenerated grating formed with different annealing recipe were compared to find the various factors in grating regeneration.By mass fabrication, Grouping experiment was conducted to research the controllability and repeatability in grating regeneration. We analyzed and verified the factors of grating repeatability to provide a basis for the technology of mass production.The properties of seed grating, regenerated grating and regenerated grating with post-annealing were measured and compared, including temperature resistance, temperature characteristic, strain characteristics and breaking point.Grating regeneration under strain was studied. Opposite experiments with gratings based on two types of fiber has been done to find the influence of strain and post-annealing temperature in grating regeneration. The wavelength shift in post-annealing was firstly observed and explained with theoretical analysis and experimental verification.