谐波锁模类噪声方波脉冲掺铒光纤激光器的研究

Harmonic Mode-Locked Noise-Like Rectangle Pulses in an Erbium-Doped Fiber Laser

本文对长腔“8”字型掺铒光纤激光器中产生谐波锁模方波脉冲进行了实验研究。该类型脉冲具有光滑的宽带光谱,在示波器上显示为方波脉冲,但自相关迹证实其为类噪声脉冲,即类噪声方波脉冲。实验中通过调节激光器腔内参数,如偏振控制器和泵浦功率等,获得了高达5阶的谐波锁模类噪声方波脉冲。实验结果表明,光纤激光器内产生的类噪声方波脉冲并非可以无限增大脉冲能量,而是在一定条件下会产生脉冲分裂,出现谐波锁模方波脉冲现象。研究结果有利于进一步理解类噪声方波脉冲的机理和特性。

We reported on the generation of harmonically mode-locked rectangular pulses in a long cavity figure-eight fiber laser. The mode-locked spectrum was broad and smooth and its pulse profile appeared to be the rectangular shape on the oscilloscope. However, the pulse type was confirmed as noise-like pulse by an autocorrelator, namely noise-like rectangular pulse. By adjusting the laser parameters, such as polarization controllers and pump power, up to 5th harmonic mode- locked noise-like rectangular pulse was achieved. It indicates that the energy of noise-like rectangular pulse in the fiber laser cannot be increased infinitely, but it may split into multiple pulses, leading to the phenomenon of harmonically mode-locked rectangular pulse. The obtained results may be useful for enhancing the understanding of the mechanism and characteristics of noise-like rectangular pulse.