Research On Y Waveguide Device Testing Method Based On White Light Interference

Nowadays,with the rapid development of IFOG(Interferometric Fiber Optic Gyro),IFOG range of applications throughout all areas,including manned space flight,satellite orientation,airborne systems and so on.Especially in the military field,it is a direct impact on the development prospects of a country's military strength.So,at home and abroad,demand for precision IFOG is more and more increasing.As the core device of IFOG,the extinction ratio of Y waveguide is direct effect of IFOG performance.However,in many test methods of extinction ratio,the accuracy of the test is very limited.How to study a method or apparatus for testing a high precision,large dynamic range has become an urgent problem to solve.Researchers in related fields at home and abroad gathered on this,carried out against the Y waveguide extinction ratio testing method of related research.This will promote the Y waveguide with more precision the unceasing development.In this thesis,based on the white light interference principle and OCDP(Optical Coherence Domain Polarimetry)system which is pre developed by the laboratory,carried out for Y waveguide extinction ration testing method of research.The main content is as follows.Firstly,starting from the principle of the partially coherent light interference,introduced and deduced the power spectral density,coherence function and coherence.By means of the principle,the testing principle of Y waveguide has constructed the theoretical model under different conditions.And through the Matlab,simulation and theoretical analysis of the constructed model.Secondly,the structure scheme of Y waveguide extinction ratio testing optical path is discussed in detail.Described from two different test optical paths,the single channel and the dual channel.And compared the advantages and disadvantages of the two optical paths.Next on the variable optical path delay device,optimization of structural scheme.Finally introduced the performance index of the optical path.Thirdly,introduced separately the parameters of Y waveguide test optical path selection,measurement and calculation method.Using the optical path,testing a large number of Y waveguide and analysis of its polarization characteristics.Research on Y waveguide extinction ratio influenced by voltage.Last but not the least,analysis of the error of Y waveguide test optical path.The related aspects of the experiment is as follows.The same waveguide multiple welding experimental,analysis of the effect of different welding angle on measurement of waveguide and Y waveguide reverse measurement experiment.The research results show that,using the OCDP system which is pre developed by the laboratory and the white light interference method,a testing system developed that can effectively enhance the dynamic range of the test system and reducing the noise background.The dynamic range is 90 dB,the noise background is-90 dB.In this thesis,the experimental effect of the testing optical path is obvious.So far,a lot of Y waveguide has been tested.And help the relevant units lay the foundation for the improvement of Y waveguide chip extinction ratio.