The Optical Characteristic Research Of Multi-core Fiber For Communication

Currently, optical communication network is developing rapidly towards large scaleand large capacity, then higher request in optical fiber communication system is put forward,faced with the huge pressure of transmission bandwidth. Under this background, multi-corefibers (MCFs) based on space division multiplexing (SDM), can overcome the congestionproblem caused by the theoretical transmission limit of single mode fiber. Multicore fiberscannot be used in the transmission system only if they have the optical properties of lowcrosstalk and large effective mode field area. In this thesis, the structure and the opticalperformance of multi-core fiber for communication system are systematically researched andanalyzed.In the first section, after the investigation on multi-core optical fiber and single modeoptical fiber coupling systems, the characteristic of each is summarized. Then by comparingthe mentioned coupling systems, the most suitable and feasible method is selected tomanufacture, that is, using the chemical corrosion to reduce the single-mode optical fibers’cladding to the size that would be matched with the multi-core optical fiber, thenaccumulating the single-mode fibers in the capillary.In the second section, the coupled theory in multi-core fiber is studied in detail, and byutilizing the method of mode coupling theory and power coupling theory, the crosstalkproperty in multi-core optical fiber is calculated by the math-tool matlab.Finally, taking seven-core optical fiber for instance, multi-core fiber structure design isundertaken, and the beam propagation method (BPM) and finite element method (FEM) areused respectively for simulating the influence of multi-core optical fiber structure parameterson crosstalk and effective mode field areas. Then the structure is comprehensively optimized,theoretically achieving optical properties with low crosstalk less than-45dB and large arealarger than130μm2. In addition, the multi-core fibers which have already drawn are taken toproceed experimental test of crosstalk and other important optical parameters, in the processof which, offset splice is exploited for the coupling of multi-core fiber and single mode fiber.