Research On Silicon Glass Packaging Technology For Fiber Bragg Grating And Its Tilt Sensor Fabrication

Fiber Bragg grating(FBG)package is an essential part of the FBG sensor fabrication process.Packaging technology provides protection for the FBG,while also transmitting strain and temperature changes to achieve a precise sensing measurement.The most commonly used packaging material is epoxy resin adhesive,which is prone to aging and failure,which further affects the performance and life of a sensor.Metal material has oxidative corrosion problems,which is hard to provide long-term accurate measurement.To improve the durability of FBG sensors,using highly durable and corrosion-resistant materials for FBG packaging has great significance.This research provides an innovative approach that enables silicon glass sensor fabrication,where the substrate and packaging material are prepared by silicon glass,which is consistent with silicon optical fiber.The main work is as follows.(1)The structure of silicon glass packaged fiber Bragg grating sensor has been designed.In the packaging process,there are three main bottleneck problems,which are considered in this study: highly elastic processing of glass used in the sensor elastic element;thermal fixation between the silicon packaging material and substrate;selecting appropriate FBG parameters and fixing methods.In the proposed approach,an elastic glass cantilever beam and an FBG are packaged with molten glass powder.The proposed approach is verified by tests,and test results show that the packaged FBG has good package quality and sensing performance.(2)The theoretical analysis of the wavelength drift phenomenon during the packaging is presented.FBG wavelength drift phenomenon and the chirp phenomenon are discussed in theory,which during to heating,cooling and curing of the silicon glass powder used in the packaging experimental.By analyzing the results,it can be concluded that when the glass powder is cooled to room temperature after curing,the larger temperature difference will greatly enlarge the overall strain and local non-uniform strain of the package area.It is necessary to ensure the uniformity of the package to avoid the FBG chirp problem.(3)Finally,the introduced packaging method is applied to the fabrication of a silicon glass FBG tilt sensor.The sensor shell,cantilever beam,temperature compensation beam,mass block,and other components are designed and made of silicon glass.The sensing principle and performance tests of the tilt sensor have been described in detail.The tilt sensor has the tilt measurement sensitivity of 6.72pm/°,the resolution of 0.015°,the linearity of 0.9999 in the range of-30°-30°,which shows good linearity and repeatability.The presented packaging technology shows good applicability and has promising application in the fabrication of high-performance FBG sensors.