Pulsed-CPT Cs-Ne microcell atomic clock with frequency stability below 2 × 10^-12 at 10⁵ s.

Area of Science:

• Atomic Physics
• Metrology
• Quantum Optics

Background:

• Table-top atomic clocks are crucial for portable timekeeping.
• Coherent Population Trapping (CPT) microcell clocks face challenges from light-shift effects and atmospheric variations.
• Previous CPT clock designs were limited in mid-term stability.

Purpose of the Study:

• To improve the mid-term stability of a table-top CPT microcell atomic clock.
• To mitigate light-shift effects and variations in the cell's inner atmosphere.
• To achieve stability competitive with current state-of-the-art microwave microcell clocks.

Main Methods:

• Implemented a pulsed symmetric auto-balanced Ramsey (SABR) interrogation technique.
• Stabilized setup temperature, laser power, and microwave power.
• Utilized a micro-fabricated cell with low permeation alumino-silicate glass (ASG) windows to reduce Ne buffer gas pressure variations.

Main Results:

• Successfully mitigated light-shift effects.
• Significantly reduced Ne buffer gas pressure variations within the microcell.
• Achieved a clock Allan deviation of 1.4 × 10^-12 at 10⁵ s.

Conclusions:

• The combined techniques provide significant improvements in CPT microcell atomic clock stability.
• The enhanced clock demonstrates mid-term stability competitive with leading microwave microcell clocks.
• This work advances the development of robust and portable atomic clocks.