The Study Of Supercontinuum Generation In Photonic Crystal Fiber

The most striking feature of photonic crystal fiber is highly nonlinear characteristic, it is prone to a variety of nonlinear effects, especially supercontinuum generation. In this text, I designed a photonic crystal fiber with high nonlinear, studied the effective area and nonlinear coefficient by multipole method. Supercontinuum generation of the photonic crystal fiber has been studied using split-step Fourier method for generalized nonlinear Schrodinger equation. The main contents are described as follows:First of all, numerical simulated the effective area and nonlinear coefficient of photonic crystal fiber using multipole method. The analysis shows that the size of nonlinear can be effectively regulated by changing the air hole pitch and air hole diameter of photonic crystal fiber.Secondly, numerical simulated the transmission of ultrashort pulses in self-designed highly nonlinear photonic crystal fiber, using split-step Fourier method for generalized nonlinear Schrodinger equation.It is found that the influence of initial durations T0, peak powers P0, initial chirp C and center wavelength on laser pulses evolution is different in PCF'different dispersion regions. If we want to obtain optimization supercontinuum,we not only choose the PCF with suit parameter but also choose fit pulse parameters.Then, I experimented the photonic crystal fiber which drawn by our group.The single core fiber which I choosed was different air hole diameter,but orderly structure.I studied the supercontinuum generation from two aspects, different pump power and center wavelength. It is found that not only spectral width but also pulse shapes different of supercontinuum generation.Finally, I experimented the only multi-core photonic crystal fiber.The spectral broadening scope over 2000 nm, this study provides a new research direction on wider range of supercontinuum without any non-linear material only rely on the structure of PCF.