光子晶体光纤中高阶非线性效应所致啁啾的研究

利用广义非线性薛定谔方程，分别数值计算了光子晶体光纤(Photonic Crystal Fiber, PCF)中的受激拉曼散射(Stimulated Raman Scattering，SRS)所致啁啾、自陡(Self-steepening，SS)所致啁啾及综合各种效应所得的总啁啾.计算结果表明：SRS啁啾的中心漂移而且正、负啁啾不对称；SS啁啾主要集中在脉冲的后沿；各种非线性总啁啾增大.由此得出，SRS引起频谱的红移与不对称，而SS则对频谱的不对称展宽贡献最大，各种非线性总的作用结果将产生不对称的红移的超 关键词： 啁啾 超连续谱 受激拉曼散射 自陡

Study of chirps induced by the higher-order nonlinear effects in the photonic crystal fiber

Based on nonlinear Schrdinger equation, the stimulated Raman scattering (SRS) chirp, self-steepening (SS) chirp and total chirps induced by all nonlinear effects in photonic crystal fiber (PCF) are simulated numerically. The results show that the center of SRS chirp wanders and the chirps of the leading edge and the trailing edge are asymmetrical, the central SS chirp mainly shifts to the trailing edge, and the total chirps increases. Thus, SRS leads to the shift of spectrum to the longer wavelength and the asymmetric broadening of spectrum, and SS is the most important contributor to the asymmetry spectrum broadening. Consequently, asymmetrical red-shift supercontinuum (SC) spectrum is finally resulted due to all nonlinear effects mentioned above.