Optical-Comb-Based Frequency Stability Transfer Across the Spectrum With a Multichannel FPGA

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Optics
• Laser Physics

Background:

• Optical frequency combs are crucial for transferring spectral properties of ultrastable lasers to different wavelengths.
• Existing methods often require individual laser stabilization and complex setups.
• Simultaneous multi-laser locking presents a significant technical challenge.

Purpose of the Study:

• To develop and demonstrate a digital locking system for simultaneous multi-laser stabilization using an optical frequency comb.
• To enable robust and independent transfer of coherence from a reference oscillator to multiple lasers.
• To showcase the system's capability in supporting advanced applications like optical clock ensembles.

Main Methods:

• Utilized a digital locking system to synchronize up to six lasers to a single reference oscillator via an optical frequency comb.
• Operated the system in a broad-linewidth regime without requiring pre-stabilization of the target lasers.
• Transferred coherence from a Yb optical lattice clock laser (1156 nm) to lasers in the 1550 nm region.

Main Results:

• Achieved simultaneous and independent locking of multiple lasers to a high-performance reference oscillator.
• Demonstrated short-term instability lower than 10⁻¹⁴ at 1 second, even in the broad-linewidth regime.
• Successfully transferred coherence to a laser used for long-distance fiber frequency dissemination with minimal instability.

Conclusions:

• The digital locking system offers a robust, reconfigurable, and modular approach for multi-laser stabilization.
• This technology minimizes setup complexity and hardware-induced effects, enabling seamless upgrades.
• The system is well-suited for applications demanding multiple ultrastable lasers, including optical clock networks, spectroscopy, and quantum simulation.