An Yb-fiber frequency comb phase-locked to microwave standard and optical reference<xref rid="cpb_29_3_030601fn1" ref-type="fn">*</xref><fn id="cpb_29_3_030601fn1"><label>*</label><p>Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA1502040404 and XDB21010400) and the National Natural Science Foundation of China (Grant Nos. 91850209 and 11774234).</p></fn>

An Yb-fiber frequency comb phase-locked to microwave standard and optical reference**

Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA1502040404 and XDB21010400) and the National Natural Science Foundation of China (Grant Nos. 91850209 and 11774234).

Wang Hui-Bo^{1, 2}, Han Hai-Nian^{2, 3, †}, Zhang Zi-Yue^{2, 3}, Shao Xiao-Dong^{2, 3}, Zhu Jiang-Feng¹, Wei Zhi-Yi^{1, 2, 3}

(a) Frequency spectrum of stabilized heterodyne beat frequency under 1 kHz RBW. The inset: linewidth of the heterodyne beat frequency. (b) Phase noise PSD of f_beat (red line) and the IPN (blue line) ranging from 1 Hz to 10 MHz. (c) Residual fluctuations of the f_beat signal with a 1 s gate. The standard deviation for f_beat is 0.54 mHz. (d) Allan deviation of the f_beat signal.