[1] Li J, Lee H, Vahala K J. Microwave synthesizer using an on-chip Brillouin oscillator [J]. Nature Communications, 2013, 4(1): 2097. doi:  10.1038/ncomms3097
[2] Xie X, Bouchand R, Nicolodi D, et al. Photonic microwave signals with zeptosecond-level absolute timing noise [J]. Nature Photonics, 2017, 11(1): 44-47. doi:  10.1038/nphoton.2016.215
[3] Fortier T M, Kirchner M S, Quinlan F, et al. Generation of ultrastable microwaves via optical frequency division [J]. Nature Photonics, 2011, 5(7): 425-429. doi:  10.1038/nphoton.2011.121
[4] Pillet G, Morvan L, Brunel M, et al. Dual-frequency laser at 1.5 µm for optical distribution and generation of high-purity microwave signals [J]. Journal of Lightwave Technology, 2008, 26(15): 2764-2773. doi:  10.1109/JLT.2008.927209
[5] Diddams S A, Vahala K, Udem T. Optical frequency combs: Coherently uniting the electromagnetic spectrum [J]. Science, 2020, 369(6501): eaay3676. doi:  10.1126/science.aay3676
[6] Liang W, Eliyahu D, Ilchenko V S, et al. High spectral purity Kerr frequency comb radio frequency photonic oscillator [J]. Nature Communications, 2015, 6(1): 7957. doi:  10.1038/ncomms8957
[7] Bai Y, Zhang M, Shi Q, et al. Brillouin-Kerr soliton frequency combs in an optical microresonator [J]. Physical Review Letters, 2021, 126(6): 063901. doi:  10.1103/PhysRevLett.126.063901
[8] Liu J, Lucas E, Raja A S, et al. Photonic microwave generation in the X-and K-band using integrated soliton microcombs [J]. Nature Photonics, 2020, 14(8): 486-491. doi:  10.1038/s41566-020-0617-x
[9] Yang Q F, Ji Q X, Wu L, et al. Dispersive-wave induced noise limits in miniature soliton microwave sources [J]. Nature Communications, 2021, 12(1): 1442. doi:  10.1038/s41467-020-20314-w
[10] Tetsumoto T, Nagatsuma T, Fermann M E, et al. Optically referenced 300 GHz millimetre-wave oscillator [J]. Nature Photonics, 2021, 15(7): 516-522. doi:  10.1038/s41566-021-00790-2
[11] Jeong D, Kwon D, Jeon I, et al. Ultralow jitter silica microcomb [J]. Optica, 2020, 7(9): 1108-1111. doi:  10.1364/OPTICA.390944
[12] Kwon D, Jeong D, Jeon I, et al. Ultrastable microwave and soliton-pulse generation from fibre-photonic-stabilized microcombs [J]. Nature Communications, 2022, 13(1): 381. doi:  10.1038/s41467-021-27699-2
[13] Lucas E, Brochard P, Bouchand R, et al. Ultralow-noise photonic microwave synthesis using a soliton microcomb-based transfer oscillator [J]. Nature Communications, 2020, 11(1): 374. doi:  10.1038/s41467-019-13993-7