Pulsed optically pumped atomic clock with zero-dead-time.

Area of Science:

• Atomic, Molecular, and Optical Physics
• Metrology and Measurement Science
• Quantum Information Science

Background:

• Pulsed optically pumped (POP) atomic clocks are crucial for precise timekeeping.
• Conventional POP clocks suffer from dead time, limiting continuous operation and introducing noise.
• Microwave phase noise is a significant factor affecting atomic clock performance.

Purpose of the Study:

• To develop a zero-dead-time (ZDT) method for POP atomic clocks.
• To eliminate dead time in POP atomic clocks for continuous local oscillator discrimination.
• To improve the frequency stability and reduce sensitivity to microwave phase noise.

Main Methods:

• Alternatively operating two POP atomic clocks to eliminate dead time.
• Implementing a ZDT method for continuous signal processing.
• Analyzing the Allan deviation and its dependence on averaging time (τ).

Main Results:

• The ZDT-POP clock demonstrates a dead-time-free operation.
• Frequency stability, measured by Allan deviation, improves significantly, approaching τ^-1 for short averaging times (0.01–1 s).
• The ZDT-POP clock's frequency stability is enhanced by an order of magnitude compared to conventional POP clocks.

Conclusions:

• The ZDT method effectively eliminates dead time in POP atomic clocks.
• This technique leads to superior frequency stability, particularly at short averaging times.
• Understanding limiting factors for short-term stability is crucial for further advancements in POP atomic clock technology.