Two-photon rubidium clock detecting 776 nm fluorescence.

Area of Science:

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

Background:

• Optical atomic clocks offer high precision for timekeeping.
• Developing compact and portable atomic clocks is crucial for next-generation applications.
• Rubidium atomic clocks are candidates for manufacturable, small-size, weight, and power (SWaP) devices.

Purpose of the Study:

• To report the first two-photon rubidium clock stabilized by detecting 776 nm fluorescence.
• To demonstrate the use of a multi-pixel photon counter (MPPC) as a low-voltage substitute for photomultiplier tubes (PMTs) in atomic clock feedback loops.

Main Methods:

• Stabilization of a two-photon rubidium atomic clock using 776 nm fluorescence detection.
• Integration of a multi-pixel photon counter (MPPC) into the clock laser's feedback loop.
• Characterization of the clock's performance with the MPPC system.

Main Results:

• Successful implementation of a two-photon rubidium clock.
• Demonstration of 776 nm fluorescence detection for clock stabilization.
• Validation of the MPPC as a viable low-voltage alternative to PMTs for clock laser feedback.

Conclusions:

• The developed two-photon rubidium clock is a promising candidate for portable, manufacturable timekeeping solutions.
• The use of MPPCs offers a path towards smaller and more power-efficient atomic clocks.
• This work advances the development of next-generation optical atomic clocks with reduced SWaP.