Study Of The Spherical Focused 3 × 1 Fiber-optic Coupler

As well known, the optical fiber coupler is a kind of passive optical devices. Its role is coupling light from an adjustable optical fiber into another or more fiber, and enabling the coupling of optical signals transmitting in the optical fiber to take place in the special coupling district. It is to achieve optical signals splitting/ combining functional devices. Generally, it splittes/combines the same wavelength of optical power. it is also known as splitter or combiner. It is widely used in optical communication, optical detection and optical fiber sensing technology and other fields.With the rapid development of optical fiber communication, optical LAN, optical user network and user access network, fiber CATV, fiber optic sensing technology, precision testing systems, fiber-coupled devices become increasingly important.. Therefore, manufacturing fiber-coupled devices to meet the requirements of reliable performance and high-volume attracts more and more attention. How to progress the coupling, enhance the coupling efficiency and improve the cost performance is a hot research topic of optical fields.The purpose of this study is designubg a good performance of the fused taper ball lens 3×1 multi-mode fiber coupler by the theory of the transmission of light,In this paper, the following aspects are mainly discussed.(1) The development and application of optical fiber technology and the current development of optical fiber coupling are introduced.(2) The optical transmission media, increasing widely used in optical communication systemk, is illustrated, including its basic concepts, classification, properties and refractive index distribution. And many characteristics of fiber are also discussed, such as its mode,transimission consumption, frequency band, connection and test measures.(3) Furthermore, the ray theory and wave theory of optical fiber transmission, the wave regulation of meridional ray and inclined ray are explicitly demonstrated. The ray theory of meridional ray in the conical fiber and ball lensed fiber is analyzed. Based on the Maxwell's equations, the wave theory of linear refractive-index fiber is given.(4) The basic characteristics, classification, performance parameters and topological structure of fiber coupler are introduced. For different couplers, their theory is also introduced. Especially, the coupling characteristics and the working principle of 3×1 fused fiber coupler is discussed. Then, using experiment instruments, the spherical focused 3×1 fiber-optic fused biconical coupler is made.(5) The three methods of making fiber coupler is introduced, chemical corrosion, polished fiber and fused biconical taper. The application and advantages of the fused biconical taper is importantly introduced. And the apparatuses used in our experiment, optic fiber conic clink and Optical Fiber Fusion splicer, are given. A focus on the ball end type 3×1 fused fiber coupler is proposed. Based on the general 3×1 fused fiber coupler, the coupling of the cone will be processed into focus the ball-side end section instead of using fiber welding machine and other fibers with welding. By tested, the performance of such a coupler fiber optic coupler has reached the general performance standards and its coupling efficiency is up to 70%. Moreover, the coupled system of alignment tolerance is greatly increased and the difficulty of debugging and packaging is decreased, which has a wide range of practical application.