基于全正色散光子晶体光纤的超连续谱光源

利用预估校正分步傅里叶法数值求解非线性薛定谔方程, 模拟超短激光脉冲在全正色散光子晶体光纤中传输时的演化情况, 分析了不同脉宽和能量的脉冲对产生的超连续谱的影响. 结果表明: 无啁啾高斯脉冲在此全正色散光子晶体光纤中传输时, 始终保持单个脉冲特性, 提高脉冲峰值功率可进一步展宽获得的超连续谱.模拟结果同时表明, 利用中心波长为1060 nm, 脉宽和能量分别为50 fs, 15 nJ的脉冲抽运此光纤, 当传输12 cm 后便可获得具有较好的光谱连续性和光谱平坦度的超连续谱. 进一步模拟结果表明, 采用棱镜对对其进行脉冲压缩, 可获得脉宽约15 fs, 谱宽约700 nm的理想超连续谱光源. 关键词： 超连续谱 光子晶体光纤 全正色散

Supercontinuum generation based on all normal dispersion photonic crystal fiber

Evolutions of ultrashort pulse in time and frequency domain are modeled based on the nonlinear schrödinger equation by predictor-corrector split-step flourier method when the pulse travels in an all normal dispersion photonic crystal fiber. And the influences of the pulse duration and energy on generated continuum are also investigated. It is shown that a single pulse is maintained in the time domain and that a larger spectrum broadening is achieved with higher peak power. When the fiber is pumped by an unchirped Gaussian pulse centred at 1060 nm with duration about 50 fs and energy 1.5 nJ, good continuum is available after only 12 cm traveling distance with fine continuity and coherence. And a perfect continuum is achieved with duration about 15 fs and spectrum about 700 nm after pulse compression by a pair of prisms.
Keywords： supercontinuum photonic crystal fiber all normal dispersion