为了抑制镱原子钟激光在光纤传输过程中引入的额外噪声，本文系统地研究了光纤噪声抑制的原理和实现方法。我们利用外差拍频的方法提取光纤传输引入的相位噪声，并通过对DDS驱动的声光调制器施加伺服反馈实现对光纤噪声的抑制。本文对比了采用光纤噪声抑制系统前后的频率噪声，采用Allan方差表征的实验结果显示，经过光纤噪声抑制系统后剩余光纤噪声引起的频率不稳定度为1.85×10-17/τ，频率噪声的起伏在秒量级的平均时间下降了一个数量级，400 s后进入E-19量级，相对于未进行光纤噪声抑制的稳定度提高了2个数量级。

The line-width of we clock laser is very narrow,we should pay attention to the noise through the optical fiber. This paper describes a fiber noise cancellation (FNC) system to suppress the frequency noise induced by the optical fiber transmission used for ytterbium (Yb) clock laser. The phase noise is extracted from heterodyne beat signals. Then the feedback signal is applied to acousto-optical modulator(AOM) driven by DDS to cancel fiber noise. Experimental results in our system show that the FNC system can effectively suppress the fiber noise. The fractional frequency instability limited by residual fiber noise is dropped to 1.85×10-17/τ for averaging times of 1-4000 s. The frequency jitter of the clock laser due to FNC system is improved by two orders of magnitude for averaging time above 400 s.