Miniaturized optical frequency reference for next-generation portable optical clocks.

Area of Science:

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

Background:

• Optical frequency standards are crucial for precision measurements and advanced technologies like optical atomic clocks.
• Current standards often require large footprints and significant power consumption.

Purpose of the Study:

• To demonstrate a compact and low-power optical frequency reference.
• To utilize the Doppler-free, two-photon transition in rubidium-87 for high-stability frequency referencing.

Main Methods:

• Implementation of a rubidium-87 two-photon transition at 778 nm on a micro-optics breadboard.
• Stabilization of a laser to the atomic transition for frequency referencing.

Main Results:

• Achieved a fractional frequency instability of 2.9×10^-12/τ for averaging times τ < 10³ s.
• The device has a compact volume of approximately 35 cm³ and consumes ≈450 mW of electrical power.

Conclusions:

• The developed optical reference represents a significant advancement in miniaturizing frequency standards.
• This technology is key for the development of compact optical clocks and widespread dissemination of SI-traceable wavelength references.