High-performance laser system for compact cold-atom optical clock.

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Metrology

Background:

• High-performance laser systems are essential for precision measurements.
• Stabilizing laser frequency to atomic transitions is critical for applications like optical clocks.

Purpose of the Study:

• To demonstrate a straightforward frequency-locking technique for a high-performance 780 nm laser system.
• To achieve multi-transition stabilization of the 87Rb D2 line.
• To enable applications in compact cold-atom optical clocks and quantum sensors.

Main Methods:

• Utilized external modulation saturation absorption spectroscopy.
• Employed a fiber electro-optic modulator for frequency modulation.
• Stabilized the laser to multiple transitions of the 87Rb D2 line.

Main Results:

• Achieved fractional frequency instability of 2.21 × 10-13 at 1 s for the cycling transition.
• Obtained a linewidth of 1.46 kHz for the cycling transition.
• Reached a record-low instability of 1.98 × 10-12 at 1 s for the repumping transition.

Conclusions:

• The developed laser system offers excellent short-term frequency stability and multi-frequency locking.
• This simplified system is a critical subsystem for compact cold-atom optical clocks.
• The metrological performance enables immediate applications in Rydberg electrometry, atomic magnetometry, and matter-wave interferometry.