提出并分析验证了一种利用有源环形滤波器对有理数谐波锁模激光器输出光脉冲幅度进行均衡的方案。方案中,光纤结构的有源环形滤波器被视为一个自由光谱范围可调谐的梳状滤波器,使有理数谐波锁模激光器输出光脉冲中的锁模分量通过而其他谐波分量和超模得到抑制,获得幅度均衡的光脉冲。理论上,对经过有源环形滤波器前后光脉冲的波形和频谱分别进行了仿真,结果表明有源环形滤波器能有效滤出所需的锁模频率,且Q值越高,光脉冲的幅度均衡效果越佳。在7阶、11阶、14阶有理数谐波锁模条件下通过实验进行验证,均获得了良好的效果,模式抑制比可提高20 d B以上。 An active loop filter is proposed and analyzed to verify the scheme of equalizing the output pulse amplitude of a rational Harmonic mode-locked laser. In the scheme, the active loop filter with optical fiber structure is regarded as a comb filter with tunable free spectral range, which allows the mode-locked part in the output optical pulse of rational Harmonic mode-locked laser to pass through while other harmonic components and supermodules Get suppressed, get amplitude balanced light pulse. Theoretically, the waveforms and spectra of the light pulse before and after passing through the active loop filter are simulated respectively. The results show that the active ring filter can effectively filter out the required mode-locked frequency. The higher the Q value, the amplitude of the light pulse Balance the better. In the 7th order, 11 order, 14 order Rational Harmonic clamping conditions verified by experiments, have achieved good results, the mode rejection ratio can be increased more than 20 d B.