Dual-interrogation method for suppressing light shift in Rb 778 nm two-photon transition optical frequency standard

Area of Science:

• Atomic Physics
• Optical Metrology

Background:

• Atomic frequency standards are crucial for precise timekeeping and scientific measurements.
• Light shifts are a significant source of error in optical frequency standards, affecting their accuracy and stability.
• The Rubidium (Rb) 778 nm two-photon transition is a promising candidate for optical frequency standards.

Purpose of the Study:

• To develop and demonstrate a novel method for suppressing light shifts in the Rb 778 nm two-photon transition optical frequency standard (2hν-OFS).
• To reduce the sensitivity of the atomic frequency standard to variations in light power.
• To enhance the overall accuracy and long-term stability of the Rb 2hν-OFS.

Main Methods:

• Implementation of a dual-interrogation (DI) technique.
• Utilizing an auxiliary system for real-time calibration of light shifts in the primary system.
• Measuring the reduction in absolute light shift and light-power sensitivity.

Main Results:

• The dual-interrogation method effectively suppressed light shifts.
• Absolute light shift and light-power sensitivity were reduced by a factor of 10.
• Demonstrated significant improvement in the performance of the Rb 778 nm 2hν-OFS.

Conclusions:

• The DI method is highly effective in mitigating light shifts in Rb 778 nm 2hν-OFS.
• This approach enhances the accuracy and stability of atomic frequency standards.
• The DI method is applicable to other vapor-cell atomic frequency standards affected by light shifts.