Fabrication And Experimental Research Of The Coupler Based On The Fine Diameter Polarization-Maintaining Fiber

In recent years,with the rapid development of China's electronics industry,defense industry,automobile industry,aerospace industry,shipbuilding industry,and so on,in all the above fields,the fiber coupler,which can realize the function of sensing.Due to the wide range of applications of fiber couplers and their special requirements in many important fields,it is imperative to develop a coupler that can be adapted to a wide range of conditions.The fine diameter Polarization-Maintaining(PM)fiber coupler is a kind of fiber coupler which is designed based on the PM fiber whose cladding diameter is only 40?m.It can be well applied in the defense industry and the aerospace industry.It accounts for a large position in the sensing field.This thesis mentioned a 2 × 2 fiber coupler based on the characteristics of the PM fiber and the specific parameters.Specific design steps are like this:1?Achieve fine diameter PM fiber fixed axis.The polarization-maintaining fiber involved in this thesis is an elliptical inner cladding PM fiber.In this application of optical fiber,we should know its axis.This is because light propagating along different axes of an optical fiber in an elliptical cladding PM fiber has a relative speed difference due to the influence of polarization when it is output,which affects the stability of the polarization state.The so-called fixed axis is the use of polarizing microscope to observe the internal structure of the PM fiber.We select the long axis of the inner cladding of the ellipse,which is facing the vertical axis as the fixed axis target.2?Design of fine diameter polarization maintaining fiber optic fixture.At present,the most widely used ordinary single-mode optical fiber with a diameter of 125 ?m,which is widely used in the laboratory.Therefore,the standard fiber optic fixture which capable of holding a size of 125 ?m or more can be buy easily.We have to design an fiber optic fixture,which capable of holding a 40 ?m cladding PM fiber?3?Use optical fiber taper technology to make fiber optic coupler.This is a very important step.As a result,we can make a coupler based on fine diameter polarization-maintaining optical fiber.This topic is aim to research fine diameter polarization maintaining fiber.By polarized imaging method and fused taper method to observe the axis and the coupler,respectively.It has an important application for the research of fiber coupler fabrication technology.