Studies On Dispersive Wave In Photonic Crystal Fiber

Pulse propagation in photonic crystal fiber is a branch of nonlinear optics issues,which includes dispersive wave generation.Dispersive wave generation is the phenomenon that energy transfer from input pulse to the new wavelength due to perturbation of nonlinear effects,high-order dispersion and loss inside the photonic crystal fiber.The exploration about dispersive wave generation makes it a tool to further understand soliton propagation issue.What's more,the generation mechanism of dispersive waves reveals the theory of supercontinuum generation.All these aspects contributes to varied kinds of application in nonlinear optical science,which has drawn global attention both on theory studying and experiments implementing.After hollowcore photonic crystal fiber is invented in 2002,the unique features offer an excellent environment to investigate the dynamics of dispersive wave generation as it can provide intense nonlinear effects,flexible and tunable dispersion and possibility of filling gas.In recent years,it became the top issue in related fields that generating dispersive wave using ultrashort pulse in a hollow-core photonic crystal fiber.In this thesis,we demonstrate the dynamics and principles of dispersive wave generation in hollow-core photonic crystal fiber and also discuss the influence factors in the process.We develop the program using nonlinear Schr?dinger equation and unidirectional pulse propagation equation according to different features of input pulse and PCFs.Our innovation and conclusion can be summarized as below:We demonstrate the intense pulse propagation dynamics inside a 10 bar Kryptonfilled Kagome Hollow-core photonic crystal fiber and summarize the influence and interplay between varied factors.The inert gas plasma induced by intense laser pulse plays a key role,which enriches new features of dispersive wave generation with the interplay of nonlinear effects and dispersion.The resulting gas ionization condition modifies the fiber dispersion,allowing phase-matching access to dispersive waves at otherwise inaccessible frequencies.These theoretical results of transferring energy from input pulse to dispersive wave pave the way to a new generation of mid-infrared or other interested frequency coherent light source.We further extend our research by launching a near-saw-tooth-shaped two-color pulse input into 7-bar Krypton-filled hollow-core Kagome photonic crystal fiber.Multiple dispersive waves are generated and frequency conversion between dispersive waves is observed at gas ionization threshold.Pulse dynamics is discussed and the frequency conversion is legitimately explained by the plasma corrected phase-matching condition.