[1] A. D. Ludlow, M. M. Boyd, J. Ye. Optical atomic clocks. Rev. Mod. Phys., 87, 637-701(2015).

[2] N. Poli, C. Oates, P. Gill. Optical atomic clocks. Riv. Nuovo Cimento, 36, 555-624(2013).

[3] W. McGrew, X. Zhang, R. Fasano. Atomic clock performance enabling geodesy below the centimetre level. Nature, 564, 87-90(2018).

[4] E. Oelker, R. Hutson, C. Kennedy. Demonstration of 4.8×10^-17 stability at 1 s for two independent optical clocks. Nat. Photonics, 13, 714-719(2019).

[5] A. Aeppli, K. Kim, W. Warfield. Clock with 8 × 10^-19 systematic uncertainty. Phys. Rev. Lett., 133, 023401(2024).

[6] S. M. Brewer, J.-S. Chen, A. M. Hankin. ²⁷Al⁺ quantum-logic clock with a systematic uncertainty below 10^-18. Phys. Rev. Lett., 123, 033201(2019).

[7] C. Sanner, N. Huntemann, R. Lange. Optical clock comparison for Lorentz symmetry testing. Nature, 567, 204-208(2019).

[8] C. J. Kennedy, E. Oelker, J. M. Robinson. Precision metrology meets cosmology: improved constraints on ultralight dark matter from atom-cavity frequency comparisons. Phys. Rev. Lett., 125, 201302(2020).

[9] C. Clivati, A. Meda, S. Donadello. Coherent phase transfer for real-world twin-field quantum key distribution. Nat. Commun., 13, 157(2022).

[10] S. Wang, Z.-Q. Yin, D.-Y. He. Twin-field quantum key distribution over 830-km fibre. Nat. Photonics, 16, 154-161(2022).

[11] C. Clivati, R. Aiello, G. Bianco. Common-clock very long baseline interferometry using a coherent optical fiber link. Optica, 7, 1031-1037(2020).

[12] G. Marra, D. Fairweather, V. Kamalov. Optical interferometry–based array of seafloor environmental sensors using a transoceanic submarine cable. Science, 376, 874-879(2022).

[13] M. Takamoto, I. Ushijima, N. Ohmae. Test of general relativity by a pair of transportable optical lattice clocks. Nat. Photonics, 14, 411-415(2020).

[14] J. Grotti, S. Koller, S. Vogt. Geodesy and metrology with a transportable optical clock. Nat. Phys., 14, 437-441(2018).

[15] J. D. Roslund, A. Cingöz, W. D. Lunden. Optical clocks at sea. Nature, 628, 736-740(2024).

[16] Z. L. Newman, V. Maurice, T. Drake. Architecture for the photonic integration of an optical atomic clock. Optica, 6, 680-685(2019).

[17] K. W. Martin, G. Phelps, N. D. Lemke. Compact optical atomic clock based on a two-photon transition in rubidium. Phys. Rev. Appl., 9, 014019(2018).

[18] T. Schuldt, K. Döringshoff, E. V. Kovalchuk. Development of a compact optical absolute frequency reference for space with 10^-15 instability. Appl. Opt., 56, 1101-1106(2017).

[19] K. Döringshoff, F. B. Gutsch, V. Schkolnik. Iodine frequency reference on a sounding rocket. Phys. Rev. Appl., 11, 054068(2019).

[20] J. H. Shirley. Modulation transfer processes in optical heterodyne saturation spectroscopy. Opt. Lett., 7, 537-539(1982).

[21] F. Bertinetto, P. Cordiale, G. Galzerano. Frequency stabilization of dbr diode laser against cs absorption lines at 852 nm using the modulation transfer method. IEEE Trans. Instrum. Meas., 50, 490-492(2001).

[22] V. Negnevitsky, L. D. Turner. Wideband laser locking to an atomic reference with modulation transfer spectroscopy. Opt. Express, 21, 3103-3113(2013).

[23] A. M. De Melo, H. Letellier, A. Apoorva. Laser frequency stabilization by modulation transfer spectroscopy and balanced detection of molecular iodine for laser cooling of ¹⁷⁴Yb. Opt. Express, 32, 6204-6214(2024).

[24] S. Lee, G. Moon, S. E. Park. Laser frequency stabilization in the 10^-14 range via optimized modulation transfer spectroscopy on the ⁸⁷Rb D₂ line. Opt. Lett., 48, 1020-1023(2023).

[25] Z. Zhang, Z. Wang, H. Liu. An ultra-stable laser based on molecular iodine with a short-term instability of 3.3×10^-15 for space based gravity missions. Class. Quantum Gravity, 40, 225001(2023).

[26] J. Sanjuan, K. Abich, L. Blümel. Simultaneous laser frequency stabilization to an optical cavity and an iodine frequency reference. Opt. Lett., 46, 360-363(2021).

[27] C. Bordé, J. Hall. Ultrahigh resolution saturated absorption spectroscopy. Laser Spectroscopy, 125-142(1974).

[28] C. J. Cuneo, J. J. Maki, D. McIntyre. Optically stabilized diode laser using high-contrast saturated absorption. Appl. Phys. Lett., 64, 2625-2627(1994).

[29] C. Zeng, Q. Zhao, C. Yang. Frequency-stabilized improvement of saturated absorption spectroscopy based on laser linewidth-control strategy. Opt. Lett., 49, 434-437(2024).

[30] R. Barger, M. Sorem, J. Hall. Frequency stabilization of a cw dye laser. Appl. Phys. Lett., 22, 573-575(1973).

[31] R. W. Drever, J. L. Hall, F. V. Kowalski. Laser phase and frequency stabilization using an optical resonator. Appl. Phys. B, 31, 97-105(1983).

[32] T. Kessler, C. Hagemann, C. Grebing. A sub-40-mHz-linewidth laser based on a silicon single-crystal optical cavity. Nat. Photonics, 6, 687-692(2012).

[33] X. Ma, Z. Cai, C. Zhuang. Integrated microcavity electric field sensors using Pound-Drever-Hall detection. Nat. Commun., 15, 1386(2024).

[34] J. Ye, L. S. Ma, J. L. Hall. Molecular iodine clock. Phys. Rev. Lett., 87, 270801(2001).

[35] J. Miao, T. Shi, J. Zhang. Compact 459-nm cs cell optical frequency standard with 2.1 × 10^-13/τ short-term stability. Phys. Rev. Appl., 18, 024034(2022).

[36] L. Winkler, C. Nölleke. Artificial neural networks for laser frequency stabilization. Opt. Express, 31, 32188-32199(2023).

[37] P. Ruksasakchai, C. Cowdell, L. Sanchez. A microcontroller based self-locking laser system. Rev. Sci. Instrum., 93, 048008(2022).

[38] A. N. Dinkelaker, M. Schiemangk, V. Schkolnik. Autonomous frequency stabilization of two extended-cavity diode lasers at the potassium wavelength on a sounding rocket. Appl. Opt., 56, 1388-1396(2017).

[39] Z. Liu, X. Guan, X. Qin. An atomic filter laser with a compact Voigt anomalous dispersion optical filter. Appl. Phys. Lett., 123, 131103(2023).

[40] P. Chang, H. Shi, J. Miao. Frequency-stabilized Faraday laser with 10^-14 short-term instability for atomic clocks. Appl. Phys. Lett., 120, 141102(2022).

[41] J. Keaveney, W. J. Hamlyn, C. S. Adams. A single-mode external cavity diode laser using an intra-cavity atomic faraday filter with short-term linewidth <400 kHz and long-term stability of <1 mHz. Rev. Sci. Instrum., 87, 095111(2016).

[42] X. Qin, Z. Liu, H. Shi. Switchable Faraday laser with frequencies of ⁸⁵Rb and ⁸⁷Rb 780 nm transitions using a single isotope ⁸⁷Rb Faraday atomic filter. Appl. Phys. Lett., 124, 161104(2024).

[43] Y. Ohman. On some new auxiliary instruments in astrophysical research VI. A tentative monochromator for solar work based on the principle of selective magnetic rotation. Stockholms Obs. Ann., 19, 9-11(1956).

[44] F. A. Jenkins, H. E. White. Fundamentals of optics. Indian J. Phys., 25, 265-266(1957).

[45] J. Menders, P. Searcy, K. Roff. Blue cesium faraday and Voigt magneto-optic atomic line filters. Opt. Lett., 17, 1388-1390(1992).

[46] F. S. Ponciano-Ojeda, F. D. Logue, I. G. Hughes. Absorption spectroscopy and stokes polarimetry in a ⁸⁷Rb vapour in the Voigt geometry with a 1.5 T external magnetic field. J. Phys. B, 54, 015401(2020).

[47] J. Keaveney, F. S. Ponciano-Ojeda, S. M. Rieche. Quantitative optical spectroscopy of ⁸⁷Rb vapour in the Voigt geometry in DC magnetic fields up to 0.4 T. J. Phys. B, 52, 055003(2019).

[48] K. Muroo, T. Matsunobe, Y. Shishido. Resonant Voigt-effect spectrum of the rubidium D₂ transition. J. Opt. Soc. Am. B, 11, 409-414(1994).

[49] M. A. Zentile, J. Keaveney, L. Weller. ElecSus: a program to calculate the electric susceptibility of an atomic ensemble. Comput. Phys. Commun., 189, 162-174(2015).

[50] J. Keaveney, C. S. Adams, I. G. Hughes. ElecSus: extension to arbitrary geometry magneto-optics. Comput. Phys. Commun., 224, 311-324(2018).

[51] F. Riehle. Frequency Standards: Basics and Applications(2006).