在主动谐波锁模光纤环形激光器实验中获得数倍于调制频率ｆｍ的高重复率脉冲序列，其中ｆｐ＝２ｆｍ的输出脉冲序列极为稳定，所得的最高锁模脉冲重复频率ｆｐ＝４ｆｍ≈６ＧＨｚ。实验证实了一种被称之为有理数谐波锁模（ＲＨＭＬ—ＲａｔｉｏｎａｌＨａｒｍｏｎｉｃＭｏｄｅ－ｌｏｃｋｉｎｇ）新技术在较低的调制频率和极简单的腔构条件下也同样成立。实验观察到ＲＨＭＬ激光器允许失谐范围不小于±２ｋＨｚ，失谐比大于１０－６。 In the active harmonic mode-locked fiber ring laser experiment to obtain several times the modulation frequency fm high repetition rate pulse sequence, of which fp = 2fm output pulse sequence is extremely stable, the highest pulse-frequency obtained pulse repetition frequency fp = 4fm ~ 6GHz. Experiments confirmed that a new technique called RHML-RationalHarmonicMode-locking is also valid at lower modulation frequencies and very simple cavity configurations. The experiment shows that the detuning range of RHML laser is not less than ± 2kHz and the detuning ratio is more than 10-6.