皮秒脉冲泵浦光子晶体光纤超连续谱产生的研究

The study on supercontinuum generation in photonic crystal fiber by picosecond seed pulses

在包含自发拉曼散射噪声的广义非线性薛定愕方程的基础上,利用单光子噪声模型,理论研究了泵浦脉冲的中心频率和峰值功率对皮秒脉冲在光子晶体光纤中时域和频域演化的影响.发现在正常色散区泵浦,由色散和自相位调制的联合作用引起光波分裂导致皮秒脉冲展宽;零色散波长附近泵浦,光波展宽以四波混频为主;反常色散区域泵浦,调制的不稳定性将初始脉冲分解成一系列孤子脉冲后,高阶孤子分裂、拉曼散射、孤子自频是导致光谱展宽的主要机制.自相位调制感应调制不稳定性在皮秒脉冲初始分裂过程中发挥了重要作用。

The peal power and input pulse wavelength effects during SC generation can be rigorously modeled within the generalized nonlinear Schrodinger equation with framework through the inclusion of appropriate stochastic variables to model quantum - limited shot noise on the injected input field. The results show light waves split caused by the combined effects of dispersion and selfphase modulation led to a broadening of picosecond pulse in the normal group velocity dispersion regime. Spectral broadening is result of Four - wave mixing sideband near the zero group dispersion wavelength regimes. In the anomalous group velocity dispersion regime, the subsequent propagation of these solitons results in an increase in the overall spectral width due to contributions from dispersive wave generation, higher order selitons split and the ＇Raman self- frequency shift. Instability played an important role in the initial picosecond pulse splitting process.