基于相移光纤光栅积分特性的超短光脉冲整形

Ultrashort Optical Pulse Shaping Based on Integral Characteristics of Phase-Shifted Fiber Grating

基于传输矩阵法和耦合模理论,分析相移光纤光栅的传输函数以及透射谱特性,结果表明相移光纤光栅具有较好的积分特性,并且相移光纤光栅的积分阶数与所插入的相移点数成正比。基于相移光纤光栅一阶积分特性设计出一种光脉冲整形结构,该结构可将高斯型超短光脉冲整形成平顶脉冲或对称三角形光脉冲。通过进一步调整结构中的加权系数,该系统还可输出非对称三角形光脉冲。当输入的高斯型光脉冲的脉宽发生±10%的波动时,仍然可以得到效果较好的平顶脉冲和三角形光脉冲,故所设计的光脉冲整形系统具有较好的稳定性。

The transmission functions and the characteristics of transmission spectra of phase-shifted fiber gratings are analyzed based on the transmission matrix method and the coupled mode theory. The results show that the phase-shifted fiber gratings have superior integral property, and the integral order is proportional to the number of inserted phase-shifted points. The pulse shaping structure is designed based on the first-order integral characteristic of phase-shifted fiber grating, which can shape the Gaussian ultrashort optical pulse into a flat-topped pulse or a symmetrical triangular light pulse. The system can output asymmetric triangular light pulses by further adjusting the weighting coefficients in the proposed structure. When the pulse width of the input Gaussian light pulse fluctuates ±10%, the flat-topped pulse and triangular light pulse with high quality can be obtained, which proves that the designed pulse shaping system has high stability.