Research On Characteristics Of Polarization Beam Splitter Based On Photonic Crystal Fiber

The development of technology has increased people's demand of information.Traditional communication is far from satisfying people's various demands of their present life.The current communication is developing in the direction of large capacity and high speed.At present,how to expand communication capacity and increase communication speed is an important task.All-optical networks are rapidly developed with super-large capacity and ultra-high speed,which is one of the emerging technologies to solve this problem.All-optical networks are supported by high-performance optical devices,polarization splitter is an important device in all-optical networks.This paper is in this context,we study the characteristics of polarization splitters based on photonic crystal fiber.The effects of different structural parameters and different background materials on the coupling length,extinction ratio and bandwidth of the polarization splitter are analyzed through mode coupling theory and full vector finite element method.The following three high-performance polarization splitters are designed by optimizing different structural parameters:1.A polarization splitter based on dual-core photonic crystal fiber(PCF)with silica glass was studied.The full vector finite element method and mode coupling theory are used to analyze the impacts of different structural parameters on the performance of polarizing splitter,we achieved a polarization splitter with high performance through optimizing the structural parameters,the results show that the extinction ratio can reach-115.802 dB at the wavelength of 1.55 ?m,the length of the splitter is 385.425 ?m,and the bandwidth is 160 nm from 1.51 ?m to 1.67 ?m,covering the S,C and L bands when the extinction ratio is less than-20 dB.The polarization splitter has important application value in coherent optical communication systems and micro-nano optics.2.A new kind of five-elliptical dual-core photonic crystal fiber polarization splitter based on tellurite glass is studied.By introducing five ellipses into the core,the symmetry of the structure is broken and the birefringence can be improved.The full vector finite element method and mode coupling theory are used to comprehensively analyze the impacts of different structural parameters on the performance of polarizing splitter,the results by optimizing the structural parameters indicate that the extinction ratio can reach124.920 dB at the wavelength of 1.55 ?m,the length of the splitter is 105.156 ?m,and the bandwidth is 165 nm from 1.467 ?m to 1.632 when the extinction ratio is more than 20 dB.Meanwhile,the polarization splitter still has high performance when the structural parameters change at(1 ± 0.5%).3.A ultra-short polarization splitter based on dual-core photonic crystal fiber with tellurite glass was designed.The full vector finite element method and mode couplingtheory are used to comprehensively analyze the impacts of structural parameters on the performance of polarizing splitter.Besides,the performance of the polarization splitter is analyzed when the background material is silica under the same structural parameters.The results by optimizing the structural parameters show that the extinction ratio of the polarization splitter based on tellurite glass is 107.21 dB,the length of the splitter is89.05 ?m,and the bandwidth is 150 nm from 1.473 ?m to 1.623 ?m when the extinction ratio is more than 20 dB,and the fault tolerance is ±1.7%.The extinction ratio of the polarization splitter based on silica glass is-39.21 dB,the length of the splitter is 360 ?m,and the bandwidth is 16 nm when the extinction ratio isless than-20 dB.