Optical system for a strontium optical lattice clock aboard the Chinese Space Station

Area of Science:

• Atomic, Molecular, and Optical Physics
• Space Science and Technology
• Metrology

Background:

• Optical lattice clocks offer unprecedented precision for timekeeping and fundamental physics research.
• Deploying these sensitive instruments in space presents significant engineering challenges due to harsh environmental conditions and size constraints.
• Previous space-based atomic clocks have primarily utilized microwave transitions, limiting achievable accuracy.

Purpose of the Study:

• To design, build, and demonstrate a compact optical system for a strontium-87 (87Sr) optical lattice clock suitable for space deployment.
• To validate the system's robustness and functionality through rigorous qualification tests and in-orbit operation.
• To advance the development of operational optical clocks in space for enhanced scientific exploration and applications.

Main Methods:

• Development of a vertically stacked, compact optical system with a volume of 0.11 m3 and mass of 53.6 kg.
• Rigorous thermal and vibration qualification testing to ensure space-readiness.
• In-orbit implementation of automated multi-stage laser stabilization and a blue magneto-optical trap for 87Sr atoms.

Main Results:

• The optical system successfully passed all pre-launch qualification tests.
• The system remained fully operational after launch aboard the Chinese Space Station.
• Automated laser stabilization and atom trapping functionalities were successfully demonstrated in orbit.

Conclusions:

• The compact 87Sr optical lattice clock system is suitable for space deployment, demonstrating resilience to launch and space environments.
• Successful in-orbit demonstration represents a significant advancement towards operational space-based optical clocks.
• This technology paves the way for future high-precision measurements and fundamental physics experiments in space.