# Development of Compact and Robust Physical System for Strontium Optical Lattice Clock  
[PERSON]  
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[PERSON]  
1 Key Laboratory of Time Reference and Application, National Time Service Center, Chinese Academy of Sciences, Xi'an 710600, China; [EMAIL_ADDRESS] (Y.C. ); [EMAIL_ADDRESS] (W.T. ); [EMAIL_ADDRESS] (F.G.); [EMAIL_ADDRESS] (G.Z. ); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (J.M.) 2  
[PERSON]  
1 Key Laboratory of Time Reference and Application, National Time Service Center, Chinese Academy of Sciences, Xi'an 710600, China; [EMAIL_ADDRESS] (Y.C. ); [EMAIL_ADDRESS] (W.T. ); [EMAIL_ADDRESS] (F.G.); [EMAIL_ADDRESS] (G.Z. ); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (J.M.) 2  
[PERSON]  
1 Key Laboratory of Time Reference and Application, National Time Service Center, Chinese Academy of Sciences, Xi'an 710600, China; [EMAIL_ADDRESS] (Y.C. ); [EMAIL_ADDRESS] (W.T. ); [EMAIL_ADDRESS] (F.G.); [EMAIL_ADDRESS] (G.Z. ); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (J.M.) 2  
[PERSON]  
1 Key Laboratory of Time Reference and Application, National Time Service Center, Chinese Academy of Sciences, Xi'an 710600, China; [EMAIL_ADDRESS] (Y.C. ); [EMAIL_ADDRESS] (W.T. ); [EMAIL_ADDRESS] (F.G.); [EMAIL_ADDRESS] (G.Z. ); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (J.M.) 2  
[PERSON]  
1 Key Laboratory of Time Reference and Application, National Time Service Center, Chinese Academy of Sciences, Xi'an 710600, China; [EMAIL_ADDRESS] (Y.C. ); [EMAIL_ADDRESS] (W.T. ); [EMAIL_ADDRESS] (F.G.); [EMAIL_ADDRESS] (G.Z. ); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (J.M.) 2  
Hefei National Laboratory, Hefei 230088, China  
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School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, China  
Correspondence: [EMAIL_ADDRESS] (C.Z. ); [EMAIL_ADDRESS] (H.C.); Tel. : +86-029-8389085 (H.C.)  
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Numerous research groups, both domestically and internationally, have delved into portable optical clocks [24; 25; 26; 27]. For instance, in 2014, the European Laboratory for Nonlinear Spectroscopy (LENS) and the Physikalisch-Technische Bundesanstalt (PTB) cooperatively demonstrated the first transportable optical clock. The physical package of this optical clock had dimensions of 120 cm \(\times\) 40 cm \(\times\) 36 cm [28]. Subsequently, in 2017, PTB reported a new type of transportable optical clock housed in a trailer, with dimensions of 80 cm \(\times\) 40 cm \(\times\) 43 cm [29]. In 2018, the Heinrich-Heine-Universitat Dusseldorf and PTB presented a compact optical lattice clock based on bosonic atoms, with a volume of 1 m\({}^{3}\) and an uncertainty of 2.0 \(\times\) 10\({}^{-17}\)[30]. In 2020, the National Time Service Center (NTSC) unveiled a compact optical clock, whose physical system had a volume of 0.3 m\({}^{2}\)[31]. RIKEN also developed a pair of transportable optical clocks in 2020 [32], encased within a magnetic shield box with a side length of approximately 60 cm [33]. More recently, the University of Birmingham presented a field-deployable atomics package designed for an optical lattice clock, which exhibited a remarkable volumetric size, occupying only 121 L, including the laser system. This development marked a significant step in the direction of highly portable optical clocks suitable for a wide range of applications [34]. Typically, after transporting a standard portable optical clock system from the laboratory to the working site, manual adjustments are made to restore the system to its optimal state. However, for specialized optical clocks, like those on space stations or satellites, manual readjustments may not be feasible. To withstand extreme vibration environments, a highly robust optical clock becomes imperative. In this manuscript, we present a strontium optical clock physical system with a compact structure and exceptional environmental adaptability.