主动有理数谐波锁模脉冲幅度均匀化方波调制实验研究

Experimental Research on Square Wave Modulation for Actively Rational Harmonic Mode-locked Pulse Amplitude Equalization

主动有理数谐波锁模的脉冲幅度不均匀化一直限制着其发展和应用,为此提出了一个新的方法,即在调制器上加载方波调制优化谐波锁模,使其脉冲幅度均匀化,通过加载方波调制,使光通过调制器的透过率在一段时间内保持不变,从而实现脉冲幅度的均匀化。实验优化了2~7阶谐波锁模,使其谐波锁模脉冲幅度均匀化,脉冲分量的功率相同,达到了优化谐波锁模的目的;对4阶和6阶情况进行了具体分析,4阶时把主频与最低谐波脉冲分量相差6 db优化到0 db,6阶时把主频与最低谐波脉冲分量相差10 db优化到0 db。实验还发现,当方波的电压加到V_(2π)时,产生的谐波锁模脉冲频率是原来的2倍。

Actively rational harmonic mode-locked pulse amplitude unequalization has been restricting its development and application.For this reason,a new method is proposed,that is to load a square wave modulation on the modulator to optimize the harmonic mode locking and make the pulse amplitude equalized.By loading the square wave modulation,the transmittance of the light passing through the modulator remains unchanged for a period of time,so as to achieve the pulse amplitude equalization.The 2 nd to 7 th order harmonic mode locking is optimized in the experiment,so that the harmonic mode-locked pulse amplitude is equalized,and the power of pulse component is the same,achieving the goal of optimizing harmonic mode locking.The 4 th and 6 th orders are analyzed.The difference between the dominant frequency and the lowest harmonic pulse component is optimized from 6 dB to 0 dB in the 4 th order,and the difference between the dominant frequency and the lowest harmonic pulse component is optimized from 10 dB to 0 dB in the 6 th order.It is also found that when the square wave voltage is increased to V_(2π),the frequency of the harmonic mode-locked pulse is twice that of the original pulse.