Generation of the 11th order rational harmonic mode-locked pulses with an arbitrary numerator in fiber-ring lasers

摘要

We report for the first time the generation of 5th, 10th and 11th order rational harmonic mode-locked pulse trains with the numerator of the detuning fraction be an arbitrary integer instead of unity used to date in conventional rational harmonic mode-locked fiber-ring lasers. Results show that the amplitude envelopes of these pulse trains are strongly modulated by some lower order rational harmonic mode locking with numerator equals to unity. This result makes it possible to generate dual- or multiple-pulse train when the detuning of the modulation frequency is close to the half of the cavity frequency. Choosing a proper numerator is also helpful in equalizing the amplitude distribution of the pulse train generated by high order rational harmonic mode locking.