It is found that the on-axis spectrum blueshift of ultrashort pulsed Hermite-Gaussian beams is relative to group velocity and pulse duration, but not to group velocity dispersion.

• 结果表明,超短脉冲厄米-高斯光束的轴上光谱蓝移,蓝移大小与群速度及脉冲宽度有关,而与群速度色散无关。