Gao Zi-Ye1, Zhu Jiang-Feng1, †, , Wang Ke1, Wang Jun-Li1, Wang Zhao-Hua2, Wei Zhi-Yi2, ‡,
(a) Autocorrelation traces of the Kerr-lens mode-locked pulses (blue dotted curve) with a sech2 fitting (red solid curve), and (b) the corresponding mode-locking spectrum.