Design And Characterization Of New Types Of Hollow-core Antiresonance Photonic Crystal Fibers

Hollow-core Photonic Crystal Fiber(HC-PCF)can transmit light through air core.Compared with traditional solid-core fiber,it has the unique advantages of low loss,high damage threshold and low non-linearity.So far,Hollow-core Photonic Bandgap Fiber(HC-PBGF)is a hollow-core fiber that can achieve the lowest loss of optical transmission.However,its scattering loss and mode coupling between the core mode and the glass surface mode limit its application to ultra-low-loss transmission in fiber optic communications.Recently,Hollow-core antiresonance(HC-AR)optical fiber with unique light guiding mechanism has become a research hotspot in the field of optical fiber.Compared with hollow-core photonic bandgap fiber,it has a wider transmission bandwidth,Low transmission loss,high mode purity,and high laser threshold damage are widely used in data communication,power transmission,nonlinear optics,bend sensing,and mid-infrared,ultraviolet(UV),and terahertz transmission.Therefore,designing HC-AR fiber with low loss,wide bandwidth,and good single-mode performance has important scientific application value.In this paper,the light guide mechanism,characteristics,and applications of HC-AR fiber are systematically studied using finite element software.The main research contents are as follows:Taking a simple single-loop HC-AR fiber as the research object,the anti-resonance reflective optical waveguide model was used to analyze the reasons for the low loss and energy band formation of the HC-AR fiber.In addition,the effects of the structural parameters of the optical fiber(tube gap,tube wall thickness,core diameter,number of tubes,and number of nested tubes)on the transmission characteristics of the fiber are systematically analyzed.Through numerical simulation,the loss and bandwidth of various HC-AR optical fibers in the communication window are studied.The design proposes two 5-tube HC-AR fibers with nested circular and elliptical antiresonant tubes.Demonstrates how the fiber transmission loss and higher-order modes are affected by the geometry and the number of antiresonant cladding tubes;and analyzes its bending loss performance.Three types of HC-AR optical fibers using anisotropic antiresonant tubes in cladding tubes are proposed.By optimizing the ellipticity of the resonant tube,the designed hollow-core fiber has low loss and single-mode transmission capability at the communication wavelength of 1.55?m,and it has the characteristics of limiting loss and high-order mode extinction ratio of conventional negative-curve hollow-core fiber,and compared with the conventional negative curvature hollow-core fiber limit loss and high-order mode extinction ratio and other characteristics.The transmission characteristics of polarization-maintaining hollow-core fibers are studied.By introducing nested tubes with different wall thicknesses in the y-polarization direction,The effects of the thickness variation of the nested tube on the limiting loss,birefringence,and polarization extinction ratio of the fiber fundamental mode were analyzed.The manufacturing tolerances were analyzed and compared with other design schemes.